AU2007201469B2

AU2007201469B2 - Developer cartridge and image forming apparatus

Info

Publication number: AU2007201469B2
Application number: AU2007201469A
Authority: AU
Inventors: Kotaro Noguchi
Original assignee: Fujifilm Business Innovation Corp
Current assignee: Fujifilm Business Innovation Corp
Priority date: 2006-09-28
Filing date: 2007-04-03
Publication date: 2009-10-22
Anticipated expiration: 2027-04-03
Also published as: CN101154074A; AU2010200134A1; CN101154074B; JP2008083549A; AU2007201469A1; JP4513793B2

Description

AUSTRALIA PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT ORIGINAL Name of Applicant/s: Fuji Xerox Co., Ltd. Actual Inventor/s: Kotaro Noguchi Address for Service is: SHELSTON IP 60 Margaret Street Telephone No: (02) 9777 1111 SYDNEY NSW 2000 Facsimile No. (02) 9241 4666 CCN: 3710000352 Attorney Code: SW Invention Title: DEVELOPER CARTRIDGE AND IMAGE FORMING APPARATUS The following statement is a full description of this invention, including the best method of performing it known to me/us: File: 53841AUP00 - la DEVELOPER CARTRIDGE AND IMAGE FORMING APPARATUS BACKGROUND Technical Field The present invention relates to a developer cartridge and an image forming 5 apparatus. Related Art Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field. 10 An image forming apparatus is configured to supply developer to a developing unit from a developer cartridge. When the developer inside the developer cartridge runs out, the developer cartridge is removed from the image forming apparatus and replaced with a new developer cartridge. An open portion that has, for example, an elongate cylinder shape and is for 15 supplying the developer to the developing unit is disposed in a side wall of the developer cartridge, and a shutter that opens and closes this open portion is disposed. A lock mechanism that locks the shutter is disposed to ensure that the shutter does not easily open in a state where the developer cartridge has been removed from the image forming apparatus (e.g., see Japanese Patent Application Publication No. 2005-37673). 20 A dedicated space is necessary in order to dispose the lock mechanism. For this reason, sometimes this hinders the miniaturization of the developer cartridge or the image forming apparatus. SUMMARY It is an object of the present invention to enable the miniaturization of a 25 developer cartridge or an image forming apparatus even when a lock mechanism that locks a shutter that opens and closes a cartridge open portion in the developer cartridge is disposed to ensure that the shutter does not easily open. In order to achieve the object of the present invention, a developer cartridge of a first aspect of the present invention is a developer cartridge that detachably attaches to an 30 apparatus body, the developer cartridge comprising: a cartridge body that is rotatable using a shaft portion disposed in the apparatus body as a rotating shaft; a shutter that opens and closes a cartridge open portion disposed in the cartridge body; and a lock mechanism that locks the shutter and, abuts the shaft portion, such that the lock -2 mechanism moves and releases the lock by, attachment of the developer cartridge to the apparatus body, and positioning of the shaft portion in a rotational center of the cartridge body. In the developer cartridge of the first aspect, the lock mechanism locks the shutter 5 that opens and closes the cartridge open portion disposed in the cartridge body, so that the shutter is prevented from easily opening and closing. Additionally, after the developer cartridge is attached to the apparatus body, the shaft portion is positioned in the rotational center of the cartridge body, whereby the cartridge body becomes rotatable using the shaft portion as a rotating shaft and the locking by the lock mechanism is released. 10 In this manner, the shaft portion functioning as a rotating shaft of the cartridge body doubles to function to release the locking by the lock mechanism. Thus, miniaturization of the developer cartridge becomes possible. Further, the lock is released as a result of the cartridge body of the developer cartridge becoming rotatable, so that the developer cartridge is prevented from becoming 15 unstable, such as being able to rotate even though the lock has not been released or being unable to rotate even though the lock has been released. In a developer cartridge of a second aspect of the present invention, the lock mechanism includes a lock member that locks the shutter and, when the shaft portion is positioned in the rotational center of the cartridge body, abuts the shaft portion, moves 20 and releases the lock. In the developer cartridge of the second aspect, the shaft portion attached to the apparatus body is positioned in the rotational center of the cartridge body, whereby the lock mechanism locking the shutter abuts the shaft portion, moves and releases the lock. In other words, the lock mechanism has a configuration that is simple and easy. Thus, it 25 becomes possible to economize the space for the lock mechanism. As a result, miniaturization of the developer cartridge becomes possible. In a developer cartridge of a third aspect of the present invention, the cartridge body includes a guide portion in which is formed a guide that guides the shaft portion to the rotational center of the cartridge body when the developer cartridge is attached to the 30 apparatus body. The developer cartridge of the third aspect includes the guide portion in which is formed the guide that guides the shaft portion to the rotational center of the cartridge body, so that when the developer cartridge is attached to the apparatus body, the guide -3 can easily and accurately guide the shaft portion to the rotational center of the cartridge body. In a developer cartridge of a fourth aspect of the present invention, the guide portion includes a cartridge biasing member that abuts the shaft portion and biases the 5 developer cartridge in an axial direction. In the developer cartridge of the fourth aspect, the cartridge biasing member abuts the shaft portion and biases the developer cartridge in the axial direction. Additionally, the developer cartridge is positioned in the axial direction as a result of causing a positioning reference surface of the developer cartridge to abut a positioning 10 reference surface disposed in the apparatus body, for example. In a developer cartridge of a fifth aspect of the present invention, the lock mechanism is disposed in the guide portion so as to be exposed from the cartridge body. In the developer cartridge of the fifth aspect, the lock mechanism is disposed in the guide portion so as to be exposed from the cartridge body, so that it becomes 15 possible to further economize the space for the lock mechanism. In a developer cartridge of a sixth aspect of the present invention, the lock mechanism includes a biasing portion that always biases the lock mechanism in the direction where the lock mechanism locks the shutter. In the developer cartridge of the sixth aspect, the lock mechanism is always 20 biased by the biasing portion in the direction where the lock mechanism locks the shutter, so that the shutter is further prevented from easily opening and closing. In a developer cartridge of a seventh aspect of the present invention, the biasing portion is formed integrally with the lock mechanism. In the developer cartridge of the seventh aspect, the biasing portion is formed 25 integrally with the lock mechanism, so the structure of the lock mechanism is simple. An image forming apparatus of an eighth aspect of the present invention comprises: the developer cartridge of any one of the first to seventh aspects; an attachment portion to which the developer cartridge detachably attaches and which includes an apparatus open portion that faces the cartridge open portion in the developer 30 cartridge; and the shaft portion, which is positioned in the rotational center of the cartridge body of the developer cartridge when the developer cartridge is attached to the attachment portion and serves as a rotating shaft when causing the cartridge body to rotate.

-4 In the image forming apparatus of the eighth aspect, the lock mechanism locks the shutter that opens and closes the cartridge open portion disposed in the cartridge body of the developer cartridge, so that the shutter is prevented from easily opening and closing. Additionally, the developer cartridge is attached to the apparatus body and the 5 shaft portion is positioned in the rotational center of the cartridge body, whereby the cartridge body becomes rotatable using the shaft portion as a rotating shaft and the locking by the lock mechanism is released. In this manner, the shaft portion that is disposed in the apparatus body and functions as a rotating shaft of the cartridge body of the developer cartridge doubles to 10 function to release the locking by the lock member. The developer cartridge and the apparatus body can be miniaturized. Further, the lock is released as a result of the cartridge body of the developer cartridge becoming rotatable, so that the developer cartridge is prevented from becoming unstable, such as being able to rotate even though the lock has not been released. 15 In an image forming apparatus of a ninth aspect of the present invention, the cartridge body is caused to rotate using the shaft portion as a rotating shaft after the developer cartridge is attached to the attachment portion and the shaft portion is positioned in the rotational center of the cartridge body and the locking of the shutter by the lock member is released, and the cartridge open portion moves in accompaniment 20 with this rotation, whereby the unlocked shutter opens and the cartridge open portion and the apparatus open portion face each other. In the image forming apparatus of the ninth aspect, as long as the shaft portion is not positioned in the rotational center of the cartridge body of the developer cartridge and the locking of the shutter by the lock mechanism is not released, the cartridge body 25 cannot be rotated using the shaft portion as a rotating shaft to open the shutter, and the cartridge open portion and the apparatus open portion cannot be caused to face each other, so the developer is more reliably prevented from spilling. As described above, according to the present invention, miniaturization of a developer cartridge or an image forming apparatus becomes possible even when a lock 30 mechanism that locks a shutter that opens and closes a cartridge open portion in a developer cartridge is disposed to ensure that the shutter does not easily open.

- 4a Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to". 5 BRIEF DESCRIPTION OF THE DRAWINGS An exemplary embodiment of the present invention will be described in detail based on the following figures, wherein: -5 FIG. I is a schematic side view showing the configuration of an image forming apparatus of the exemplary embodiment of the present invention; FIG. 2 is a perspective view showing a developer cartridge of the exemplary embodiment of the present invention; 5 FIG. 3A is a view showing a state where a shutter of a cylinder portion of the developer cartridge is closed; FIG. 3B is a view showing a state where the shutter of the cylinder portion of the developer cartridge is open; FIG. 4 is a view showing an attachment portion of a developing unit; 10 FIGS. 5A is a cross-sectional views showing the developer cartridge being attached to the attachment portion; FIGS. 5B is a cross-sectional views showing the developer cartridge being attached to the attachment portion; FIGS. 5C is a cross-sectional views showing the developer cartridge being 15 attached to the attachment portion; FIG. 6 is a view showing the developer cartridge being attached to the attachment portion; FIG. 7 is a perspective view showing a guide member seen from inside; and FIG. 8A is a cross-sectional view of both end portions of the developer cartridge; 20 FIG. 8B is a front view of one end portion of the developer cartridge. DETAILED DESCRIPTION An exemplary embodiment of the present invention will be described in detail below based on the drawings. It will be noted that arrow FR represents a front side and 25 arrow RE represents a rear side. As shown in FIG. 1, an image forming apparatus 10 includes an apparatus body 12, and an image forming portion 14 including a rotary developing device 16 is disposed in the substantial center portion of the apparatus body 12. A paper supply cassette 18 in which recording paper is stored is disposed in the 30 lower portion of the apparatus body 12. A feed roller 22 that feeds the recording paper from the paper supply cassette 18 and retard rollers 24 that sort the fed recording paper one sheet at a time are disposed in front of (in the direction of arrow FR) and above the paper supply cassette 18.

-6 A conveyance path 20 is a recording paper path from the feed roller 22 to a discharge opening 30. The conveyance path 20 is formed at the front side of the image forming apparatus 10 in a substantially vertical direction from the paper supply cassette 18 to a later-described fixing device 70. A later-described second transfer roller 66 and a 5 second transfer backup roller 60 are disposed upstream of the fixing device 70 on the conveyance path 20. A registration roller 26 is disposed upstream of the second transfer roller 66 and the second transfer backup roller 60. Further, discharge rollers 28 are disposed in the vicinity of the discharge opening 30 on the conveyance path 20. Consequently, the recording paper is fed by the feed roller 22 from the paper 10 supply cassette 18 and sorted by the retard rollers 24 so that just the uppermost sheet of the recording paper is guided to the conveyance path 20. Then, the recording paper is temporarily stopped by the registration roller 26 and sent between (second transfer portion) the later-described second transfer roller 66 and the second transfer backup roller 60 at a timing. 15 The rotary developing device 16 is disposed somewhat toward the rear side of the substantial center portion of the apparatus body 12. The rotary developing device 16 includes a rotating body 34 that houses therein developing units 38Y, 38M, 38C, and 38K that respectively form toner images of the four colors of yellow (Y), magenta (M), cyan (C), and black (K), and the developing device 16 is configured to rotate leftward 20 (counter-clockwise in FIG. 1) about a rotating shaft 36. The developing units 38Y, 38M, 38C, and 38K respectively include developing rollers 40Y, 40M, 40C, and 40K, and are pushed in the substantial radial direction of the rotating body 34 by elastic bodies 42 comprising coil springs, for example. Further, an image carrier 44 comprising a photoconductor drum, for example, is 25 disposed so as to abut the rotary developing device 16. Part of the outer periphery of each of the developing rollers 40Y, 40M, 40C, and 40K protrudes about 2 mm, for example, from the outer periphery of the rotating body 34 in a state where the developing rollers 40Y, 40M, 40C, and 40K are not abutting the image carrier 44. It will be noted that tracking roller (not shown) having a diameter slightly larger than the 30 diameter of the developing rollers 40Y, 40M, 40C, and 40K are disposed on both ends of each of the developing rollers 40Y, 40M, 40C, and 40K so as to rotate coaxially with the developing rollers 40Y, 40M, 40C, and 40K.

-7 That is, the developing rollers 40Y, 40M, 40C, and 40K of the developing units 38Y, 38M, 38C, and 38K are disposed on the outer periphery of the rotating body 34 at intervals of 90 degrees around the rotating shaft 36. The tracking rollers of the developing rollers 40Y, 40M, 40C, and 40K abut flanges (not shown) disposed on both 5 ends of the image carrier 44, so that a predetermined gap is formed between the developing rollers 40Y, 40M, 40C, and 40K and the image carrier 44, and the developing rollers 40Y, 40M, 40C, and 40K develop, with toner of their respective colors, a latent image on the image carrier 44. Further, a charge roller 46 serving as a charge member that uniformly charges the 10 surface of the image carrier 44 is disposed below the image carrier 44. Additionally, a cleaning blade 48 serving as a cleaning member abuts the image carrier 44 downstream of the charge roller 46 in the rotational direction of the image carrier 44. Waste toner remaining on the image carrier 44 after first transfer is scraped off by the cleaning blade 48. 15 Further, an exposure device 50 that uses a light beam such as a laser beam to write the latent image on the image carrier 44 uniformly charged by the charge roller 46 is disposed below the rotary developing device 16. Further, an intermediate transfer device 52 that conveys, from the image carrier 44 that is a first transfer portion to the second transfer roller 66 that is a second transfer portion, the toner image made visible 20 by the rotary developing device 16 is disposed in front of the rotary developing device 16. The intermediate transfer device 52 is configured by an intermediate transfer belt 54 serving as an intermediate transfer body, a wrap-in roller 56, a wrap-out roller 58, the second transfer backup roller 60, and tension rollers 62 and 64. The intermediate transfer 25 belt 54 pulled out frontward due to the second transfer backup roller 60 abuts the second transfer roller 66. The intermediate transfer belt 54 includes a first transfer portion (image carrier wrap region) that wrappingly abuts the image carrier 44 between the wrap-in roller 56 and the wrap-out roller 58, is wrapped around a predetermined range of the image carrier 30 44, and is configured to follow the rotation of the image carrier 44. After the toner image on the image carrier 44 has been firstly transferred, the intermediate transfer belt 54 conveys the firstly transferred toner image to the second transfer backup roller 60.

-8 The second transfer roller 66 faces the second transfer backup roller 60 of the intermediate transfer device 52 with the conveyance path 20 being interposed between the second transfer roller 66 and the second transfer backup roller 60. In other words, the area between the second transfer roller 66 and the second transfer backup roller 60 5 serves as the second transfer portion, and the second transfer roller 66 is assisted by the second transfer backup roller 60 in secondly transferring, to the recording paper, the toner image firstly transferred onto the intermediate transfer belt 54. It will be noted that, although it is not shown, a cleaning member that scrapes off waste toner remaining on the intermediate transfer belt 54 after second transfer is disposed in the vicinity of the 10 tension roller 62. Further, the fixing device 70 is disposed above (downstream of) the second transfer portion. The fixing device 70 includes a heat roller 72 and a pressure roller 74 and is configured to cause the toner image secondly transferred to the recording paper by the second transfer roller 66 and the second transfer backup roller 60 to be fixed to the 15 recording paper by heating/pressuring and fusing, with the heat roller 72 and the pressure roller 74. When the toner image transferred to the recording paper is fixed by the fixing device 70, the recording paper is discharged by the discharge rollers 28 through the discharge opening 30 into a discharge portion 32. The discharge portion 32 is slanted 20 such that its portion near the discharge opening 30 is low and such that it gradually becomes higher in the direction of its back side (rear direction). Next, the process of image formation will be described. When an image forming signal is sent to the image forming apparatus 10, the image carrier 44 is uniformly charged by the charge roller 46. Then, the uniformly 25 charged image carrier 44 is irradiated with a light beam based on an image signal from the exposure device 50. In other words, the light beam from the exposure device 50 exposes the surface of the image carrier 44, whereby a latent image is formed. The latent image formed on the surface of the image carrier 44 by the exposure device 50 is developed as toner images of the respective colors of yellow (Y), magenta 30 (M), cyan (C), and black (K) by the rotary developing device 16, and the toner images are superposed on the intermediate transfer belt 54 and firstly transferred, whereby a full-color toner image is formed on the intermediate transfer belt 54. After first transfer, -9 waste toner remaining on the image carrier 44 is scraped off by the cleaning blade 48 and is recovered. The recording paper stored in the paper supply cassette 18 is fed by the feed roller 22 according to a paper supply signal and the like, sorted by the retard rollers 24, 5 guided to the conveyance path 20, temporarily stopped by the registration roller 26, and conveyed to the second transfer portion at a timing. When the recording paper is guided to the second transfer portion, the full-color toner image on the intermediate transfer belt 54 is secondly transferred to the recording paper by the second transfer roller 66 and the second transfer backup roller 60. After 10 second transfer, waste toner remaining on the intermediate transfer belt 54 is scraped off by the cleaning blade (not shown) and is recovered. In this manner, the recording paper to which the full-color toner image has been transferred is guided to the fixing device 70, where the full-color toner image is fixed to the recording paper by heat and pressure from the heat roller 72 and the pressure roller 15 74. Then, the recording paper to which the full-color toner image has been fixed is discharged by the discharge rollers 28 through the discharge opening 30 and into the discharge portion 32. The developing units 38Y, 38M, 38C, and 38K of the rotary developing device 16 are respectively disposed with developer cartridges 1OY, 1OOM, 1OOC, and lOOK 20 that store developer of their corresponding colors of yellow (Y), magenta (M), cyan (C), and black (K). The developer cartridges 1OGY, lOOM, IOOC, and lOOK are detachably attached to attachment portions 200Y, 200M, 200C, and 200K of the developing units 38Y, 38M, 38C, and 38K, and supply new developer. Then, when the developer inside the developer cartridges I OY, I OOM, I OC, and 100K runs out, the developer cartridges 25 1 OY, 1 OM, I OOC, and 100K are removed from the apparatus body 12 and replaced with new developer cartridges lOGY, lOOM, 1OOC, and lOOK. In the present exemplary embodiment, two-component developer comprising toner and carrier is used for the developer. Further, a "trickle" development system is employed. 30 The trickle development system is a development system that gradually replenishes the developer in order to prevent deterioration of the charge performance of the developer and extend the interval of developer replacement, and at the same time, - 10 perform development while discharging (recovering) excessively degraded (including a lot of degraded carrier) developer. Next, the developer cartridges 1OY, 1OOM, 1OOC, and 1OOK will be described. It will be noted that, because the developer cartridges IOOY, 1OOM, IOOC, and lOOK all 5 have the same configuration, the letters Y, M, C, and K will be omitted. As shown in FIG. 2, each of the developer cartridges 100 has an overall elongate cylinder shape whose longitudinal direction is the axial direction of the rotating shaft 36 (see FIG. 1) of the rotary developing device 16. The developer cartridge 100 is disposed with a cartridge body 102 that houses 10 developer. The outer shape of the cross section of the cartridge body 102 orthogonal to the longitudinal direction is egg-shaped. Further, the cartridge body 102 is disposed with a cylinder portion 150 that extends from one longitudinal-direction end portion 102A in the longitudinal direction. The outer shape of the cross section of the cylinder portion 150 orthogonal to the longitudinal direction is smaller than that of the cartridge body 102 15 and is substantially circular. The cartridge body 102 includes a handle portion 104 that protrudes in the longitudinal direction from the end portion 102A, curves, and connects to an end portion of the cylinder portion 150. Additionally, a gap 300 is formed between the handle portion 104 and the cylinder portion 150. 20 As shown in FIG. 3B, disposed in a side wall 152 of the cylinder portion 150 of the cartridge body 102 are a replenishment opening 154, which replenishes the developing unit 38 with the developer inside the developer cartridge 100, and a recovery opening 156, which recovers the developer discharged from the developing unit 38 to the developer cartridge 100. 25 A shutter 160 in the form of a circular arc plate having a shape following the curvature of the side wall 152 is disposed on the outer side of the side wall 152 of the cylinder portion 150. As shown in FIG. 3A and FIG. 3B, the shutter 160 moves (slides) along the side wall 152 in the circumferential direction (direction orthogonal to the longitudinal direction) to open and close the replenishment opening 154 and the 30 recovery opening 156. The trajectory along which the shutter 160 moves is disposed in the gap 300 between the handle portion 104 and the cylinder portion 150. That is, the shutter 160 is - 11 configured to enter the gap 300 when the shutter 160 is moved in order to open the replenishment opening 154 and the recovery opening 156 (see also FIG. 5C). Moreover, as shown in FIG. 5A, a seal member 162 comprising an elastic member such as a sponge that seals the area around the replenishment opening 154 and 5 the recovery opening 156 when the shutter 160 is closed is adhered to the backside of the cylinder portion 150 side of the shutter 160. Further, a projecting portion 158 that pushes against an end portion of the seal member 162 is disposed on the side wall 152 of the cylinder portion 150 in order to enhance sealability. As shown in (b)-1 and (c)-1 of FIG. 6, a guide member 250 is disposed on the 10 end portion of the developer cartridge 100. A guide 252 for guiding a shaft portion 500 disposed in the apparatus body 12 to the rotational center of the cartridge body 102 is formed in the guide member 250. The guide 252 is shaped like an inwardly recessed groove and becomes wider in the width direction toward the insertion side of the shaft portion 500. Further, a circular portion 253 is formed in the distal end portion (rotational 15 center portion) of the guide 252 to enable the developer cartridge 100 to rotate using the shaft portion 500 as a rotating shaft. Moreover, a biasing claw 254 (see FIG. 7, FIG. 8A and FIG. 8B) that elastically deforms in the longitudinal direction is disposed on a longitudinal-direction end surface portion (bottom surface of groove of the guide 252) of the guide member 250. 20 As shown in (a)-1 of FIG. 6 and in FIG. 7, a lock mechanism 380 is disposed in the guide member 250. The lock mechanism 380 includes a lock member 400 that is disposed inside the guide member 250 and comprises a square rod-shaped first member 402 and second member 404 which form an L shape. As shown in (b)-1 and (c)-1 of FIG. 6, a distal end portion 404A of the second member 404 of the lock member 400 is 25 inserted into a lock hole 160C in the shutter 160, whereby the shutter 160 is locked. It will be noted that FIG. 7 is a view of the guide member 250 seen from inside. Further, as shown in FIG. 7, a spring portion 406 is integrally formed on the upper portion of the first member 402 of the lock member 400. The lock member 400 is biased by the elasticity of the spring portion 406 in the direction where the distal end 30 portion 404A of the second member 404 is inserted into the lock hole 160C in the shutter 160. Thus, the shutter 160 is ordinarily locked by the lock member 400. Further, as shown in FIG. 6, the first member 402 of the lock member 400 is exposed to the circular - 12 portion 253 of the guide 252. Further, the lock member 400 is configured to be slidable in the vertical direction in (a)-1 of FIG. 6 and in FIG. 7. Next, the attachment portions 200Y, 200M, 200C, and 200K to which the developer cartridges I OOY, I OOM, I OOC, and 100K detachably attach will be described. 5 It will be noted that, because the attachment portions 200Y, 200M, 200C, and 200K also are all configured in the same manner, the letters Y, M, C, and K will be omitted. As shown in FIG. 4, a receiving portion 202 curved in a substantially circular arc following the curvature of the side wall 152 of the cylinder portion 150 of the developer cartridge 100 is disposed in the attachment portion 200. As shown in FIGS. 5A to 5C, a 10 replenishment opening 204 and a recovery opening (not shown) that respectively face the aforementioned replenishment opening 154 and recovery opening 156 (see FIG. 2) in the developer cartridge 100 are formed in the receiving portion 202. Moreover, a shutter 260 that opens and closes the replenishment opening 204 and the recovery opening is disposed in the receiving portion 202 so as to be movable in the circumferential 15 direction. Further, a seal member 210 comprising an elastic member such as a sponge is adhered to the area around the replenishment opening 204 and the recovery opening. Further, a projecting portion 207 that pushes against an end portion of the seal member 210 is disposed on the shutter 206 in order to enhance sealability. 20 Next, the attachment of the developer cartridge 100 to the attachment portion 200 will be described using FIGS. 5A to 5C and FIG. 6. It will be noted that, although illustration of the recovery opening 156 in the developer cartridge 100 and the recovery opening in the attachment portion 200 is omitted in FIGS. 5A to 5C, their operation is the same as that of the replenishment opening 154 in the developer cartridge 100 and the 25 replenishment opening 204 in the attachment portion 200. As shown in FIG. SA and FIG. 5B, the cylinder portion 150 of the developer cartridge 100 attaches to the receiving portion 202 of the attachment portion 200. An end portion 160A of the shutter 160 of the developer cartridge 100 abuts the end portion of the receiving portion 202. It will be noted that, at this time, the replenishment opening 30 154 and the recovery opening 156 in the developer cartridge 100 and the replenishment opening 204 and the recovery opening (not shown) in the attachment portion 200 do not face each other and are respectively closed by the shutter 160 of the cartridge and the shutter 206 of the attachment portion.

- 13 As shown in (a)-l, (a)-2, (b)-1, (b)-2, (c)-1 and (c)-2 of FIG. 6, when the developer cartridge 100 is attached to the attachment portion 200, the shaft portion 500 is guided by the guide 252 of the guide member 250 and enters the circular portion 253 when attachment is complete. 5 At this time, the first member 402 of the lock member 400 is pushed. Then, the distal end portion 404A of the second member 404 of the lock member 400 escapes from the lock hole 160C in the shutter 160, whereby the lock is released. When the lock is released, as shown in FIGS. 5B and 5C and in (a)-2, (a)-3, (b) 2, (b)-3, (c)-2 and (c)-3 of FIG. 6, the handle portion 104 is turned to cause the 10 developer cartridge 100 to rotate. At this time, the end portion 160A of the shutter 160 of the developer cartridge 100 does not move because it is abutting the end portion of the receiving portion 202. In other words, the shutter 160 opens when the replenishment opening 154 and the recovery opening 156 in the cylinder portion 150 move. Moreover, the shutter 206 of the attachment portion 200 opens in association with the rotation of 15 the developer cartridge 100. As shown in FIG. 5C, the replenishment opening 154 and the recovery opening 156 in the developer cartridge 100 and the replenishment opening 204 and the recovery opening (not shown) in the attachment portion 200 face each other. The developer cartridge 100 is removed in the opposite sequence of what has 20 been described above. Further, when the developer cartridge 100 is removed, the lock member 400 is biased by the spring portion 406, whereby the distal end portion 404A of the second member 404 is inserted into the lock hole 160C in the shutter 160 so that the shutter 160 becomes locked in a closed state. When the developer cartridge 100 is to be attached to the attachment portion 200, 25 the biasing claw 254 of the guide member 250 that elastically deforms in the longitudinal direction pushes against the shaft portion 500, whereby the developer cartridge 100 is biased in the longitudinal direction (axial direction). Then, a positioning reference surface 260 opposite of the guide member 250 of the developer cartridge 100 is brought to abut a positioning reference surface 502 disposed in the apparatus body 12 30 opposite of the shaft portion 500, whereby the developer cartridge 100 is positioned in the axial direction. Next, the action of the present exemplary embodiment will be described.

- 14 The lock member 400 of the lock mechanism 380 locks the shutter 160 that opens and closes the replenishment opening 154 and the recovery opening 156 disposed in the side wall 152 of the cylinder portion 150 of the cartridge body 102 of the developer cartridge 100, so the shutter 160 is prevented from opening easily. 5 Additionally, after the developer cartridge 100 is attached to the attachment portion 200, the shaft portion 500 is positioned in the rotational center of the cartridge body 102, whereby the cartridge body 102 becomes rotatable using the shaft portion 500 as a rotating shaft, and the locking by the lock mechanism 380 is released. Specifically, the distal end portion 404A of the second member 404 of the lock 10 member 400 locks the shutter 160 as a result of being inserted into the lock hole 160C in the shutter 160, and the first member 402 of the lock member 400 is brought to abut the shaft portion 500 and the lock member 400 is pressed, whereby the distal end portion 404A of the second member 404 escapes from the lock hole 160C and the lock is released. Thus, the lock mechanism 380 has a configuration that is simple and easy. 15 Further, the lock member 400 of the lock mechanism 380 is disposed inside the guide member 250 in which is formed the guide 252 that guides the shaft portion 500 to the rotational center when the developer cartridge 100 is attached to the attachment portion 200. In this manner, the shaft portion 500 functioning as a rotating shaft of the 20 developer cartridge 100 doubles to function to release the locking by the lock mechanism 380. Further, the configuration of the lock mechanism 380 is also simple and easy. Moreover, the lock mechanism 380 is disposed in the guide member 250. Consequently, the space for the lock mechanism 380 is small (space is economized). Thus, miniaturization of the developer cartridge becomes possible in 25 correspondence to that amount. Further, the apparatus body 12 can also be miniaturized because a member for the lock mechanism is not separately required (because a member other than the shaft portion 500 is not required). Further, as long as the shaft portion 500 is not positioned in the rotational center of the developer cartridge 100 and the locking of the shutter 160 by the lock mechanism 30 380 is not released, the developer cartridge 100 cannot be rotated using the shaft portion 500 as a rotating shaft. In other words, as long as the locking of the shutter 160 is not released, the developer cartridge 100 cannot be rotated to open the shutter 160, and the replenishment opening 154 and the recovery opening 156 in the cartridge cannot be - 15 caused to face the replenishment opening 204 and the recovery opening in the apparatus, so the developer is reliably prevented from being spilled. Further, the developer cartridge 100 is prevented from becoming unstable, such as being able to rotate even though the lock is not released or being unable to rotate even though the lock is released. 5 Further, the guide 252 of the guide member 250 can easily and accurately guide the shaft portion 500 to the rotational center because the guide 252 guides the shaft portion 500 to the rotational center. Further, the biasing claw 254 abuts the shaft portion 500, biases the developer cartridge 100 in the axial direction, and causes the positioning reference surface 260 of 10 the developer cartridge 100 to abut the positioning reference surface 502 of the apparatus body 12, whereby the developer cartridge 100 is accurately positioned in the axial direction. Further, the shutter 160 is reliably prevented from easily opening and closing in a state where the developer cartridge 100 has been removed from the apparatus body 12 15 because the spring portion 406 formed integrally with the lock member 400 always biases the lock member 400 in the locking direction (the direction where the distal end portion 404A of the second member 404 of the lock member 400 is inserted into the lock hole 160C in the shutter 160). Moreover, the configuration of the lock mechanism 380 is simple because the spring portion 406 is formed integrally with the lock member 400. 20 The present invention is not limited to the preceding exemplary embodiment. For example, in the preceding exemplary embodiment, two-component developer comprising toner and carrier is used as the developer, but the developer is not limited to this. It suffices for the developer to include at least toner, and one-component developer comprising only toner may also be used. Further, the development system does not have 25 to be the trickle development system. Further, in the preceding exemplary embodiment, the open portion in the developer cartridge 100 is configured by two openings - the replenishment opening 154 and the recovery opening 156 - but the open portion is not limited to this. The open portion may also be configured by one opening or by three or more openings. 30 Further, in the preceding exemplary embodiment, the image forming apparatus 10 utilizes a four-cycle system that uses only one photoconductor to form a color image, but the image forming apparatus 10 may also utilize a tandem system that uses plural -16 photoconductors to form a color image. The image forming apparatus may also be one for black-and-white images. The foregoing descriptions of the exemplary embodiments of the present invention have been provided for the purposes of illustration and description. It is not 5 intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The exemplary embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the 10 various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.

Claims

1. A developer cartridge that detachably attaches to an apparatus body, the developer cartridge comprising: 5 a cartridge body that is rotatable using a shaft portion disposed in the apparatus body as a rotating shaft; a shutter that opens and closes a cartridge open portion disposed in the cartridge body; and a lock mechanism that locks the shutter and, abuts the shaft portion, such that the 10 lock mechanism moves and releases the lock by, attachment of the developer cartridge to the apparatus body, and positioning of the shaft portion in a rotational center of the cartridge body.

2. The developer cartridge of claim 1, wherein the cartridge body includes a guide portion in which is formed a guide that guides the shaft portion to the rotational center of 15 the cartridge body when the developer cartridge is attached to the apparatus body.

3. The developer cartridge of claim 2, wherein the guide portion includes a cartridge biasing member that abuts the shaft portion and biases the developer cartridge in an axial direction.

4. The developer cartridge of claim 2, wherein the lock mechanism is disposed in 20 the guide portion so as to be exposed from the cartridge body.

5. The developer cartridge of any one of the preceding claims wherein the lock mechanism includes a biasing portion that always biases the lock mechanism in the direction where the lock mechanism locks the shutter.

6. The developer cartridge of claim 5, wherein the biasing portion is formed 25 integrally with the lock mechanism.

7. An image forming apparatus comprising: a developer cartridge that detachably attaches to an apparatus body, the developer cartridge including a rotatable cartridge body, a shutter that opens and closes a cartridge open portion disposed in the cartridge body, and a lock mechanism that locks -18 the shutter and, abuts a shaft portion, such that the lock mechanism moves and releases the lock by, attachment of the developer cartridge to the apparatus body, and positioning of the shaft portion in a rotational center of the cartridge body; an attachment portion to which the developer cartridge detachably attaches and 5 which includes an apparatus open portion that faces the cartridge open portion in the developer cartridge; and the shaft portion, which is positioned in the rotational center of the cartridge body of the developer cartridge when the developer cartridge is attached to the attachment portion and serves as a rotating shaft when causing the cartridge body to 10 rotate.

8. The image forming apparatus of claim 7, wherein the cartridge body is caused to rotate using the shaft portion as a rotating shaft after the developer cartridge is attached to the attachment portion and the shaft portion is positioned in the rotational center of the cartridge body and the locking of the shutter by 15 the lock mechanism is released, and the cartridge open portion moves in accompaniment with this rotation, whereby the unlocked shutter opens and the cartridge open portion and the apparatus open portion face each other.

9. The image forming apparatus of claim 7 or claim 8, wherein the cartridge body 20 includes a guide portion in which is formed a guide that guides the shaft portion to the rotational center of the cartridge body when the developer cartridge is attached to the apparatus body.

10. The image forming apparatus of claim 9, wherein the guide portion includes a cartridge biasing member that abuts the shaft portion and biases the developer cartridge 25 in an axial direction.

IH. The image forming apparatus of claim 9 or claim 10, wherein the lock mechanism is disposed in the guide portion so as to be exposed from the cartridge body.

12. The image forming apparatus of any one of claims 9 to 11, wherein the lock mechanism includes a biasing portion that always biases the lock mechanism in the 30 direction where the lock mechanism locks the shutter. - 19

13. The image forming apparatus of claim 12, wherein the biasing portion is formed integrally with the lock mechanism.

14. A developer cartridge that detachably attaches to an apparatus body, the developer cartridge comprising: 5 a cartridge body that is rotatable using a shaft portion disposed in the apparatus body as a rotating shaft; a shutter that opens and closes a cartridge open portion disposed in the cartridge body; and a lock mechanism including a lock member that locks the shutter and, abuts the 10 shaft portion, such that the lock mechanism moves and releases the lock by, attachment of the developer cartridge to the apparatus body, and positioning of the shaft portion in a rotational center of the cartridge body, the cartridge body including a guide portion in which is formed a guide that guides the shaft portion to the rotational center of the cartridge body when the developer 15 cartridge is attached to the apparatus body.

15. A developer cartridge substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.

16. An image forming apparatus substantially as herein described with reference to 20 any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.