Process cartridge, main body cartridge, image carrier body cartridge, developing cartridge, toner cartridge, and image forming apparatus

An image forming apparatus is provided which can be switched between states in which a developing roller is attached to an image carrier body by applying a pressing force to a developing cartridge and a state in which the developing roller can be released from attachment from the image carrier body. When an operation part of a toner cartridge is arranged at an installation position a pressing force can be applied to a developing cartridge by protruding parts fitting with spring parts, and a developing roller can be attached to a photoconductor drum by the applied pressure. When the operation part is arranged at a removal position, the fitting can be undone, causing the applied pressure to be released.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from Japanese Patent Application Nos. 2005-138779, filed on May 11, 2005, and 2005-149750, filed May 23, 2005, the entire subject matter of which is incorporated herein by reference.

FIELD

Aspects of the present invention relate to an image forming apparatus of a so-called electronic photographic system that forms an image by developing an electrostatic latent image formed on an image carrier body using toner and causing the image to adhere to a recording medium, and to a process cartridge, a main body cartridge, an image carrier body cartridge, a developing cartridge, and a toner cartridge that can be used in the image forming apparatus.

BACKGROUND

In the past, image forming apparatuses have included an image carrier body, having a surface on which an electrostatic latent image is formed, a developing roller, which causes toner to adhere to the surface of the image carrier body to develop the electrostatic latent image, a transfer roller, which transfers to a recording medium the toner that has adhered to the surface of the image carrier body by the developing roller, and a toner cartridge, in which the toner is accommodated and that is configured so that it can be installed and removed.

In this type of image forming apparatus, when an electrostatic latent image is formed on the surface of the image carrier body, the developing roller causes toner that is held in a toner cartridge to adhere to the surface of the image carrier body to develop the electrostatic latent image. Then, it is possible to form an image that corresponds to the electrostatic latent image on the recording medium by the transfer roller transferring the toner that has adhered to the surface of the image carrier body to the recording medium.

In addition, in this type of image forming apparatus, pressure attachment of a developing means such as a developing roller to an image carrier body that uses and OPC (organic photoconductor), etc. is performed using a spring, etc., and the development is performed. However, when the OPC and the developing roller continue to be mutually pressure attached for a long period of time without rotation, there is a possibility of chemical damage to the OPC occurring or of the developing roller becoming permanently deformed. In this regard, it has been proposed that the two be separated by configuring the developing roller and the image carrier body so that they can approach and separate and inserting a wedge member between the developing means and the image carrier body at the time of shipping of the image forming apparatus.

SUMMARY

Certain aspects of the present invention are directed to a process cartridge. According to one illustrative aspect a process cartridge includes an image carrier body having a surface on which an electrostatic latent image is formed, a developing roller configured to cause toner to adhere to the surface of the image carrier body to develop the electrostatic latent image, and a single or plural separable housing configured to support the image carrier body and the developing roller, the housing configured to allow the developing roller to be attached to said image carrier body and to be detached from said image carrier body in response to a pressing force. Also, the process cartridge includes a toner cartridge, for holding the toner, the toner cartridge being configured to be installed in and removed from the housing, and a pressure attachment device that is configured to attach the image carrier body and the developing roller by applying a pressing force when the toner cartridge is installed in the housing and is configured release the pressure attachment of the image carrier body and the developing roller when the toner cartridge is removed from the housing.

DETAILED DESCRIPTION

Next, illustrative aspects of the present invention will be explained using the drawings.FIG. 1is an oblique view that shows the external appearance of a laser printer1functioning as the image forming apparatus according to an illustrative application of the present invention. As shown inFIG. 1, a paper feed cassette3is installed at the bottom part of the cover2that covers the main body of a laser printer1from the outer circumference A lid portion4of the cover2is provided at the front surface (specifically, at the surface arranged in the front at the time of installation of the laser printer1) of the cover2.

The lid part4includes a finger grip part4aat the top of both of the left and right ends. By pulling the finger grip part4a, it is possible to open the lid part4in a forward direction centering on the hinge4bof the lower end as shown inFIG. 2. In addition, as shown inFIG. 2, a paper feed cassette3is provided so that it can be pulled out toward the front. As such, the paper feed cassette3can be installed in and removed from a laser printer1.

Next,FIG. 3is a vertical cross sectional drawing that shows the internal configuration of the laser printer1. As shown inFIG. 3, a support plate5that has energy imparted to it in an upward direction by a spring6is provided in the interior of the paper feed cassette3, and a paper feed roller9, which feeds paper (not shown in the drawing) held in a stacked state on the support plate5toward the image forming part7separately one sheet at a time, is arranged further up on the front surface side of the support plate5. In addition, a conveyance roller11, which operates in conjunction with the paper feed roller9to convey the paper, and a guide13, which returns the paper conveyed by the conveyance roller11approximately 180° along the outer circumference of the paper feed roller9, and a pair of resist rollers14and15, which catch the front edge of the paper by appropriately stopping and adjusting the angular advance of the paper, are sequentially arranged in the conveyance path of the paper from the paper feed roller9to the image forming part7.

The image forming part7includes a photoconductor drum21as the image carrier body provided inside the photoconductor cartridge20and a transfer roller22opposing the photoconductor drum21. Note that the photoconductor drum21is a well-known type that forms an organic photoconductor (OPC) layer on the surface of a grounded metal core.

The paper, which passes between this photoconductor drum21and transfer roller22and on which an image resulting from toner is formed in the manner discussed below, is fed to a fixing part31. At the fixing part31, the toner image that is formed on the paper is held between a heating roller33and a transfer roller35and fixed by the heat, and the paper on which the image has been fixed is further conveyed by a pair of conveyance rollers36and36.

The paper, which has been conveyed by the conveyance rollers36and36, is guided above the cover2by a guide37, and is ejected to a paper eject tray39provided on the upper surface of the cover2by a pair of paper eject rollers38and38. In addition, a scanner unit90, which exposes the photoconductor drum21using laser light L, is arranged between the paper eject tray39and the photoconductor cartridge20.

Next, the configuration of the image forming part7and the scanner unit90will be explained in further detail. The photoconductor cartridge20as the image carrier body cartridge includes a photoconductor drum21so as to be rotatable and further includes a scorotron charging unit23that uniformly charges the surfaces of the transfer roller22and the photoconductor drum21. An electrostatic latent image is formed by laser light L incident from the scanner unit90via an exposure aperture part20aon the surface of the photoconductor drum21charged by the scorotron charging unit23. Next, the electrostatic latent image is developed by a developing roller41provided on a developing cartridge40by supplying toner to the surface of the photoconductor drum21. This is because the toner that has adhered to the photoconductor drum21is transferred to the paper that has passed the aforementioned transfer roller22, and an image is formed on that paper by the above operation.

The developing roller41is rotatably supported by the developing cartridge40as shown inFIG. 3and comes into contact with the photoconductor drum21and is rotated and driven by a mechanism discussed below. The developing cartridge40includes an installation part42that supports a toner cartridge60so that it can be installed and removed and an aperture part42a, by which toner is supplied from the toner cartridge60, is bored into the installation part42. In addition, a lower auger43, which conveys the toner supplied from the aperture part42aprovided at the center portion in the shaft direction to both sides in the shaft direction, an upper auger44, which conveys the toner that has been conveyed by the lower auger43and has accumulated at both sides in the shaft direction to the center portion of the shaft direction and returns it to the toner cartridge60via the aperture part42a, a supply roller45, which feeds the toner conveyed by the lower auger43toward the developing roller41, and a developing blade47, which through friction charges the toner that has adhered to the surface of the developing roller41by the supply roller45and forms a thin layer of toner, are provided in the developing cartridge40. Also, an agitator61for agitating the accommodated toner and supplying it to the developing cartridge40side is provided in the interior of the toner cartridge60.

Next, the configuration of the scanner unit90will be explained. Scanner unit90includes a polygon mirror91, which deflects and scans the laser light L generated by a laser emission part that is not shown in the drawing, and mirrors92,93that return the laser light L deflected by that polygon mirror91toward the photoconductor drum21. Also, an fit lens95and a cylindrical lens97are respectively fixed in the optical path of the laser light L that has reached mirror92from the polygon mirror91and in the optical path of the laser light L that has reached mirror93from mirror92.

Through the above configuration, it is possible to form an electrostatic latent image on the surface of the photoconductor drum21by emitting laser light L at the appropriate timing while rotating the polygon mirror91and the photoconductor drum21. Then, in the aforementioned way, image formation by an electronic photographic system is possible by developing the electrostatic latent image using toner via a developing roller41and transferring it to paper.

FIG. 4is a side view that shows the external appearance of the photoconductor cartridge20, the developing cartridge40, and the toner cartridge60. At the time of image formation, the operation part62of the toner cartridge60is arranged at the installation position shown inFIG. 3andFIG. 4(A), and in this state, the three parts, which are the photoconductor cartridge20, the developing cartridge40, and the toner cartridge60, are unified. For this reason, when the lid part4is opened and, also, the operation part62is pulled forward when the operation part62has been arranged at the installation position, the aforementioned three parts can be taken out as a unit from the installation and removal port2a(seeFIG. 3) to outside the main body of the laser printer1. Note that the installation and removal port2ais an aperture part of the cover2that is closed by the lid4.

When the operation part62of the toner cartridge60is rotated upward and arranged at the removal position shown inFIG. 4(B), the toner cartridge60is separated from a photoconductor cartridge20and a developing cartridge40, and when that operation part62is further pulled forward, it is possible to separate only the toner cartridge60as shown inFIG. 4(B)and take it out from the removal port2ato outside the main body of the laser printer1, Through this, it is possible to replace the toner cartridge60.

In addition, a rotary shaft41a(seeFIG. 5) of the developing roller41protrudes from the side surface of the developing cartridge40, and fits into a slot20bthat is bored into the photoconductor cartridge20. Due to this fitting, the developing cartridge40is movably linked to the photoconductor cartridge20along the line that joins the photoconductor drum21and the installation part42. In addition, when the operation part62is arranged at the installation position, the developing roller41is attached to the photoconductor drum21by applying a pressing force as explained below, and when the operation part62is arranged at the removal position, the pressing force is released.

Next, the configuration for installing and removing the toner cartridge60in this way will be explained. First, the configuration for switching between linkage and separation of the developing cartridge40and the toner cartridge60will be explained.

FIGS. 5(A)and (B) show how the operation part62of the toner cartridge60has been arranged at the removal position, whereFIG. 5(A)is a drawing of the installation part42of the developing cartridge40as seen from the toner cartridge60side, andFIG. 5(B)is a drawing of the toner cartridge60as seen from the installation part42side.

As shown inFIG. 5(B), the toner cartridge60includes a long cylindrical inner cylinder63whose interior accommodates the toner and an outer cylinder64that fits onto the outside of the center portion of that inner cylinder63. The outer cylinder64is installed on the installation part42so that it cannot be rotated by engaging a protruding stripe64athat protrudes at the installation part42side with a long groove42bformed on the inner wall surface of the installation part42. The inner cylinder63is such that the aforementioned operation part62is molded as a unit, and it is configured at the inner side of the outer cylinder64so that it is able to rotate according to the operation of the operation part62.

In addition, as shown inFIG. 5(A), a shutter48including a metal plate is arranged at the inside of the installation part42. The shutter48is arranged so that it is movable in the direction of the inner circumference of the installation part42between the position at which the aperture part42aof the installation part42is closed and a position (refer toFIG. 5(C)) arranged to be shifted above the aperture part42aas shown inFIG. 5(A)by supporting both ends by the rails42cformed at the inner wall surface of the installation part42.

Four protrusions63awhich interpose the vicinity of both ends of the shutter48from both sides of the circumferential direction are formed on the surface of the inner cylinder63. For this reason, the shutter48moves according to the rotation of the inner cylinder63, and when the operation part62is arranged at the removal position, as shown inFIG. 5(A), the shutter48is arranged at a position that closes the aperture part42a. Note that the long groove42bdiscussed above is formed further below that so that it does not stack with the shutter48arranged at this position. In addition, the aperture part42ais formed in a lengthwise shape that is long in the horizontal direction, and a rectangular frame-shaped sponge49that surrounds the aperture part42ais affixed at the inner wall surface of the installation part42in that vicinity.

An aperture part64bof the same shape as aperture part42ais formed at a portion of the outer cylinder64that opposes aperture part42awhen the protruding stripe64ais engaged with the long groove42b, and a sponge65of the same shape as sponge49is affixed in the vicinity thereof. In addition, an aperture part63bof the same shape as aperture part64bis formed on the inner cylinder63as well, but when the operation part62is arranged at the removal position, aperture part64band aperture part63bdo not stack at all, as shown inFIG. 5(B). For this reason, the toner of the interior does not spill even when the toner cartridge60is removed.

In addition, after the protruding stripe64ahas engaged with the long groove42b, when the operation part62of the toner cartridge60is arranged at the installation position, aperture part64band aperture part63bstack as shown inFIG. 5(D). In addition, at this time, as shown inFIG. 5(C), the shutter48is moved to above aperture part42aby the protrusions63a, so both aperture part64band aperture part42acommunicate, and it becomes possible to supply the toner from the toner cartridge60to developing cartridge40.

Also, at this time, sponge49and sponge65closely adhere, and, moreover, the engagement parts63cformed on the outer circumference surface of the inner cylinder63engage with the rails42c, so the vicinities of aperture parts64band42aare tightly sealed, and toner is prevent from spilling out to the exterior. In addition, through this engagement of the engagement parts63cand rails42c, the developing cartridge40and the toner cartridge60are linked. Conversely, by arranging the operation part62at the removal position and releasing the engagement of the engagement parts63cand the rails42c, the direct linkage between the developing cartridge40and the toner cartridge60is released.

Also, a gear901that rotates in unison with the agitator61is arranged at the outer side of one end of the inner cylinder63, and a gear902for transmitting driving force to that gear901is exposed at a position that opposes the gear901of the installation part42. For this reason, by installing the toner cartridge60in the installation part42and engaging the engagement parts63cwith the rails42cin the manner discussed above, it is possible to drive the agitator61via gears902and901.

Furthermore, the rotary shaft903of gear901protrudes to the left and right as shown inFIGS. 5(B)and (D), and a gear905is arranged at the other end of the rotary shaft903. A gear906for transmitting driving force to the lower auger43and the upper auger44is exposed at a position that opposes gear905of the installation part42. Note that the driving force transmission mechanisms of these will be discussed below.

As shown inFIG. 4, guide grooves42dthat guide this rotary shaft903are formed at the left and right end surfaces of the installation part42. The rotary shaft903is guided by the guide grooves42dat the time of installation of the toner cartridge60, so it is easy to engage the protruding stripe64awith the long groove42b.

Next,FIG. 6(A)is a drawing of the photoconductor cartridge20, the developing cartridge40, and the toner cartridge60as seen from the front surface side when the operation part62has been arranged at the aforementioned installation position, andFIG. 6(B)is a drawing of the photoconductor cartridge20, the developing cartridge40, and the toner cartridge60as seen from the front surface side when the operation part62has been arranged at the aforementioned removal position.

As shown inFIGS. 6(A)and (B), an aperture part64dthat passes through the operation part62so that rotation is possible in the aforementioned way is formed on the front surface side of the outer cylinder64. In addition, protruding parts67that are supported on the surface of the inner cylinder63by support parts66and that protrude in the left and right direction further than the installation part42are provided on both the left and right side surfaces of the operation part62.

FIG. 7(A)is a side view that shows the configuration of the photoconductor cartridge20, andFIG. 7(B)is a partial view that shows the configuration of the front surface side end portion of the photoconductor cartridge20from the inner surface side. As shown inFIG. 7(B), concave spring parts25into which protruding parts67fit when the operation part62has been arranged at the installation position are arranged in the vicinity of the front surface side end part of the photoconductor cartridge20. The spring parts25are configured to be slidable centering on fulcrums25aand impart energy in the direction of the photoconductor drum21through compression coil springs26in relation to receiving plates20cmolded as a unit at the front surface side of the photoconductor cartridge20.

For this reason, when the operation part62is rotated to the installation position, and the protruding parts67are fit into the spring parts25, as shown inFIG. 8(A), the developing cartridge40is pressed in the direction of the photoconductor drum21via the toner cartridge60, and the developing roller41is pressure attached to the photoconductor drum21. In addition, at this time, the shutter48is opened, engagement parts63cand rails42cengage, and aperture parts42a,63b, and64bcommunicate, so it is possible to perform image formation in the aforementioned way.

Conversely, when the operation part62is rotated to the removal position, and the fitting of the protruding parts67and the spring parts25is undone, as shown inFIG. 8(B), the aforementioned pressing is released. In addition, at this time, the shutter48is closed, the engagement of engagement parts63cand rails42cis released, and aperture parts63band64bare arranged to be mutually unaligned, so it is possible to remove the toner cartridge60without spilling toner. Note that, as shown inFIG. 6, the receiving plates20cand the spring parts25are arranged at the outer side in the left and right directions of the toner cartridge60and the installation part42, so these do not become and obstruction at the time of installation and removal of the toner cartridge60. Also, as shown inFIG. 2andFIG. 3, and interference member4cis provided in a protruding manner at the inner surface of the lid part4, and the configuration is such that, if the operation part62is not arranged at the installation position, that operation part62and interference member4cinterfere with each other, and it is not possible to close the lid part4.

Next, the mechanism for transmitting driving force to the developing roller41, etc. will be explained. Returning toFIG. 7(A), a metal rotary shaft21aof the photoconductor drum21protrudes from the photoconductor cartridge20at both the left and right sides, and a gear21bthat rotates in unison with the photoconductor drum21is exposed from the end portion of the rear side (installation direction side) of the photoconductor cartridge20.

In contrast with this, as shown inFIG. 9, a guide groove121that guides the rotary shaft21ais formed on the inner wall surface of the left side of the main body of the laser printer1, and a gear121bthat meshes with gear21bis provided. By this gear21band gear121bmeshing with each other at the time of installation of the photoconductor drum20, driving force can be transmitted from the main body side to the photoconductor drum21.

To continue,FIG. 10(A)is a left side surface view that shows the configuration of the developing cartridge40and the toner cartridge60, andFIG. 10(B)is a right side surface view that shows the configuration of the developing cartridge40and the toner cartridge60. As shown inFIG. 10(A), a drive shaft51through which driving force is transmitted from the drive shaft151(seeFIG. 9) of the main body side is provided at the left side surface of the developing cartridge40. Note that, in addition to drive shaft151, at the end face, comprising a flat protruding part151aand drive shaft51being formed into a cylindrical concave part into which drive shaft151can fit, a protrusion51athat is able to engage with flat protruding part151ais formed, and a so-called drive coupling is formed by the two.

As shown inFIG. 10(A), a gear51bthat rotates in unison is formed on drive shaft51, and this gear51bmeshes with a gear41bthat rotates in unison with the developing roller41, a gear45athat rotates in unison with the supply roller45, and gear902discussed above. In addition, gear901, which rotates in unison with rotary shaft903of the agitator61meshes with gear902at the time of installation of the toner cartridge60in the aforementioned way, and, in the same way, driving force is transmitted to a gear906via a gear905that rotates in unison with rotary shaft903.

As shown inFIG. 10(B), gear906meshes with gears43aand44a, which respectively rotate in unison with the lower auger43and the upper auger44. For this reason, driving force is transmitted from drive shaft151to drive shaft51, and, through that driving force, it is possible to rotate the developing roller41, the supply roller45, the agitator61, the lower auger43, and the upper auger44.

In a laser printer1configured in the above way, if the toner cartridge60is caused to be removed from the installation part42at the time of shipping, it is possible to maintain a state in which the pressure attachment of the photoconductor drum21and the developing roller41has been released as shown inFIG. 8(B). For this reason, it is possible to prevent chemical damage to the photoconductor drum21and permanent deformation of the developing roller41.

Also, as shown inFIG. 8(A), it is possible to pressure attach the developing roller41to the photoconductor drum21merely by installing the toner cartridge60in the installation part42, so operability at the time of the start of usage is improved. Furthermore, the pressure attachment is released again when the toner cartridge60is removed from the installation part42and replaced, so it is possible to better prevent chemical damage to the photoconductor drum21and permanent deformation of the developing roller41. Moreover, at this time, the rotary shaft41aof the developing roller41is guided by a slot20b, so it is possible to perform the pressure attachment and pressure attachment release even more smoothly, and the positional relationship between the photoconductor drum21and the developing roller41also becomes difficult to move.

In addition, if the toner cartridge60is installed in the installation part42, in the manner discussed above, the photoconductor drum20, the developing cartridge40, and the toner cartridge60are made into a unit, and it is possible to perform installation and removal as a unit along the guide groove121. Therefore, in the laser printer1, the ability to resolve jam handling can be improved. Also, by the protruding parts67fitting into the spring parts25and pressing the toner cartridge60in the direction of the developing cartridge40, a state in which the photoconductor drum20, the developing cartridge40, and the toner cartridge60are joined is maintained at at least two locations, making it possible to reinforce the strength of the rails42cand the engagement parts63c.

Note that, in the above illustrative aspect, the photoconductor cartridge20, the developing cartridge40, and the toner cartridge60can correspond to a process cartridge, the photoconductor cartridge20and the developing cartridge40can correspond to the main body cartridge, the housing portion of the photoconductor cartridge20and the developing cartridge40can correspond to the housing, protruding parts67, spring parts25, and compression coil springs26or like can correspond to the pressure attachment device, rails42cand engagement parts63ccan correspond to the engagement parts, protruding parts67and the fitting parts can correspond to the action receiving parts, spring parts25can correspond to the fitting receiving parts, and shutter48and outer cylinder64can correspond to the shielding member.

Also, aspects of the present invention are not limited in any way to the above described aspects, and it is possible to implement various modes within a scope that comports with aspects of the present invention. For example, as shown inFIG. 11, the slot20bmay be opened on the toner cartridge60side. In this case, from the state shown inFIG. 11(A), when the toner cartridge60is removed as shown inFIG. 11(B)in the same way as in the above aspect, as shown inFIG. 11(C), it is possible to easily separate the developing cartridge40from the photoconductor cartridge20. Therefore, it is possible to respectively individually replace the photoconductor cartridge20, the developing cartridge40, and the toner cartridge60according to the lifespan of the photoconductor drum21and the developing roller41, etc.

In addition, an elastic member that generates a pressing force for attaching the developing roller41to the photoconductor drum21may be provided on the toner cartridge60side.FIG. 12(A)is a side surface view that shows the configuration of the toner cartridge60according to this aspect. As shown inFIG. 12(A)and inFIG. 12(B)as a partial enlarged drawing thereof, in addition to holes62abeing bored in the vicinity of protruding parts67of the operation part62, protruding parts67are formed by a single shaft that passes through the holes62a. In addition, the support parts66of protruding parts67are formed by elastic members such as rubber, and the protruding parts67are made displaceable within the holes62ashown inFIG. 12(C)by elastic deformation of the support parts66.

In this case, there is no need to provide spring parts25in the photoconductor cartridge20, and, as shown inFIG. 13, concave fitting receiving parts20dinto which the protruding parts67fit may be provided. According to this aspect, when the operation part62is arranged at the installation position, and the protruding parts67are fit into the fitting receiving parts20das shown inFIG. 13(A), it is possible apply a pressing force to attach a developing roller41to a photoconductor drum21by the imparted energy applied from the support parts66. When the operation part62is arranged at the removal position as shown inFIG. 13(B), the aforementioned fitting is undone, and it is possible to release the aforementioned pressure attachment, and, in that state, it is possible to remove the toner cartridge60as shown inFIG. 13(C). Note that, according to this aspect, the support parts66may be configured by coil springs or plate springs other than rubber ones. Furthermore, the attachment may be performed by fitting resin protruding parts and fitting receiving parts with each other without using elastic members.

Furthermore, aspects of the present invention can also be applied to image forming apparatuses of the type in which the toner cartridge is installed and removed from the side of the developing cartridge. In this case as well, if the configuration is such that the toner cartridge is replaced once the entire process cartridge is removed, by using an appropriate link mechanism, etc., it is possible to link the installation and removal of the toner cartridge with the aforementioned pressure attachment/pressure attachment release. However in the above respective aspects, it is possible to individually replace the toner cartridge60from the front side of the laser printer1, which can result in improved maintenance.

In addition, the pressure attachment device may be provided on the image forming apparatus main body.FIG. 14is a vertical cross sectional view that shows the configuration according to this aspect. As shown inFIG. 14, a pressing member102as the pressure attachment device is arranged on a support plate101that supports the photoconductor cartridge20in the main body of the laser printer1. This pressing member102is provided so that it is able to slide in the forward and back directions by way of a guide101aintegrated with the support part101. The pressing member102also imparts energy toward the back by a coil spring103. In addition, the pressing member102includes a groove part102athat engages with the operation part62when that operation part62is arranged at the installation position.

For this reason, when the toner cartridge60is installed on the installation part42, and the operation part62is rotated to the operation position, the operation part62engages with the groove part102a, and the imparted energy of the coil spring103is transmitted to the developing roller41by the toner cartridge60. On the other hand, at the time of replacement of the toner cartridge60, the operation part62is rotated to the removal position while pulling the pressing member102to the front. When this is done, the aforementioned imparted energy is transmitted to the developing roller41, and it also becomes possible to remove the toner cartridge60. Therefore, according this aspect, the same action and effects as in the aforementioned respective aspects are produced.