Patent Grant
11378909
The present invention relates to an image forming apparatus for forming an image on a recording medium, and an image forming unit used in the image forming apparatus.
Heretofore, an image forming apparatus that adopts an electrophotographic system has been disclosed, in which a member for performing an electrophotographic process is arranged in a cartridge that can be attached to and detached from the apparatus body, so that a user or a maintenance operator can perform replacement operations easily and usability is improved thereby. Japanese Patent Application Laid-Open Publication No. 2009-157389 discloses a configuration where a process cartridge including a photosensitive drum and a developing roller is attached to a tray that can be drawn out of an apparatus body, and by inserting the tray to the apparatus body, the process cartridge can be attached to the apparatus body. Meanwhile, there are photosensor units equipped with a waste toner conveyance member for conveying waste toner that has not been transferred to a photosensitive member. Japanese Patent Application Laid-Open Publication No. 2002-196585 discloses a configuration in which a developing unit uses driving force received from the apparatus body to drive the waste toner conveyance member of a cleaning unit.
According to the configuration disclosed in the above-described document, the cleaning unit equipped with the photosensitive drum and the developing unit equipped with the developing roller are arranged in a single cartridge.
The present invention provides an image forming unit, in which a second cartridge is arranged detachably from a first cartridge and in which driving force can be transmitted from the second cartridge to the first cartridge, and an image forming apparatus including the image forming unit.
According to one aspect of the invention, an image forming unit to be attached to an apparatus body of an image forming apparatus includes: a first cartridge including a driven portion configured to rotate on a first rotational axis; and a second cartridge configured separable from the first cartridge, the second cartridge including: an input portion configured to receive driving force from the apparatus body; and a drive transmission portion configured to rotate on a second rotational axis and to transmit the driving force to the driven portion.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
Now, embodiments for carrying out the present invention will be described with reference to the drawings.
Examples of image forming apparatuses in the following description include copying machines, printers, multifunction devices, commercial printing devices and so on. Image is formed on a recording medium based on image information entered from an external computer or image information read from documents. Various types of sheet material of various materials and shapes can be used, such as normal paper and thick paper, plastic films, coated paper, special-shaped sheets such as envelopes and index sheets, and cloth.
An image forming apparatus according to a first embodiment will be described.
The process unit PU is an image forming unit according to the present embodiment that can be attached to and detached from the apparatus body of the image forming apparatus. Further, the photoconductor cartridge B is a first cartridge according to the present embodiment, and the developing cartridge C is a second cartridge according to the present embodiment.
General Configuration of Image Forming Apparatus
As illustrated in
As illustrated in
In a state where the image forming apparatus IF receives an instruction, i.e., print start signal, to start forming an image to the sheet P, the photosensitive drum 62 is driven to rotate at a predetermined peripheral speed, i.e., processing speed, in the direction of arrow R. The charging roller 66 to which bias voltage has been applied contacts an outer peripheral surface of the photosensitive drum 62 and charges a surface of the drum uniformly and evenly. The laser scanner 3 irradiates a laser beam L modulated based on the image information (refer to
As illustrated in
In parallel with this process, feeding of sheet P is carried out at a synchronized timing with an exposing operation by the laser scanner 3. The pickup roller 5a illustrated in
The sheet P to which toner image has been transferred is separated from the photosensitive drum 62 and conveyed to the fixing unit 9 along the conveyance guide 8. The fixing unit 9 includes a rotary member pair composed of a heating roller 9a and a pressure roller 9b, and a heat source, such as a halogen lamp, that heats the sheet P through the heating roller 9a. The fixing unit 9 applies heat and pressure to the toner image on the sheet while nipping and conveying the sheet P. Thereby, toner particles are melted and then adhered, by which the image is fixed to the sheet P. The sheet P having gone through the image fixing process is discharged by the sheet discharge roller pair 10 onto the sheet discharge tray 11 provided on an upper portion of the apparatus body A.
The cleaning member 77 removes foreign substances such as residual toner remaining on the photosensitive drum 62 that has not been transferred to the sheet P at the transfer portion. Thereby, the surface of the photosensitive drum 62 is cleaned to be prepared for the next image forming process.
Configuration of Cartridge of Process Unit
Next, a configuration of the process unit PU will be described. In the following description, a rotational axis direction, i.e., axial direction, of the photosensitive drum 62 and an axial direction of the developing roller 32 arranged in parallel therewith are referred to as a reference axis direction, in other words, longitudinal direction, of the photoconductor cartridge B and the developing cartridge C. In the reference axis direction, a side having a coupling for the photoconductor cartridge B and the developing cartridge C to receive driving force from the apparatus body A is referred to as a drive side of the photoconductor cartridge B and the developing cartridge C, and a side opposite therefrom is referred to as a non-drive side.
As illustrated in
The photosensitive drum 62 has both ends thereof in the reference axis direction supported rotatably by the cleaning frame member 71, and it is configured to rotate in an arrow R direction in the drawing by receiving driving force from a drive motor (not shown) which serves as a driving source provided on the apparatus body A. Specifically, as illustrated in
The cleaning member 77 includes a cleaning blade 77a serving as a blade-shaped member formed of an elastic material such as rubber, and a support member 77b that supports the blade. The cleaning blade 77a is in contact with the photosensitive drum 62 in a counter direction with respect to the direction of rotation of the photosensitive drum 62. That is, the cleaning blade 77a is inclined with respect to a radial direction of the photosensitive drum 62 that passes the contact point with the drum surface so that a tip portion thereof is arranged upstream in the direction of rotation of the photosensitive drum 62 as it approaches the rotational axis of the photosensitive drum 62. Further, a drum contact sheet 65 for preventing leakage of waste toner from the cleaning frame member 71 is arranged at an edge of an opening portion of the cleaning frame member 71 to which the photosensitive drum 62 is arranged, so as to contact the photosensitive drum 62.
The charging roller 66 is rotatably supported at both end portions in the reference axis direction by the cleaning frame member 71 via a charging roller bearing 67. Further, the charging roller 66 is pressed against the photosensitive drum 62 by having the charging roller bearing 67 pressed toward the photosensitive drum 62 by an urging member 68. The charging roller 66 rotates along with the photosensitive drum 62. The portions (71, 72, 77) having excluded the photosensitive drum 62 and the charging roller 66 from the photoconductor cartridge B constitute a cleaning unit 60 whose main function is to clean the photosensitive drum 62.
The developing cartridge C includes the developing roller 32, the magnet roller 34, a developer container 23, a developing blade 42, and a roller contact sheet 33. The magnet roller 34 is arranged on an inner side of the developing roller 32, and it is fixed to the developer container 23. The developing blade 42 and the roller contact sheet 33 are arranged at an opening portion of the developer container 23 to which the developing roller 32 is arranged. The developing blade 42 regulates a layer thickness of toner T that is borne on the developing roller 32 and moves toward the developing area, and applies frictional charge to toner T. The roller contact sheet 33 prevents toner T in the toner supply chamber 28 from leaking to the exterior of the developing cartridge C.
The above-described toner chamber 29 and toner supply chamber 28 are formed on the inner side of the developer container 23. A first conveyance member 43, a second conveyance member 44 and a third conveyance member 50 are arranged in the toner chamber 29, and the respective conveyance members 43, 44 and 50 function as agitating members that agitate toner T, and convey the toner T toward the toner supply chamber 28 while agitating the same. The developer container 23 constitutes a casing 20 of the developing cartridge C together with a driven-side side member 26 (refer to
The developing roller 32 has both end portions thereof in the reference axis direction supported rotatably by bearing members 27 and 37 (refer to
As illustrated in
Attachment and Detachment of Cartridge
Next, a configuration for attaching and detaching the photoconductor cartridge B and the developing cartridge C to and from the apparatus body A will be described.
The apparatus body A includes a driven-side plate 15 which is opposed to the photoconductor cartridge B and the developing cartridge C in the attached state from a drive side in the reference axis direction X, and a non-driven-side plate 16 which is opposed from a non-drive side thereto. A guide member described later for supporting attachment and detachment of the photoconductor cartridge B is attached to the driven-side plate 15 and the non-driven-side plate 16. Further, a tray 18 for supporting attachment and detachment of the developing cartridge C is arranged removably from the apparatus body A through the cartridge insertion port 17.
At first, an attachment and detachment configuration of the photoconductor cartridge B will be described. As illustrated in
Furthermore, the photoconductor cartridge B is inserted and the first guided portion 71h gets apart from the guide member 19b. At approximately the same timing, the first guided portion 73e on the drive side gets apart from the guide member 19a. Since the first guided portions 73e and 71h leave the guide members 19a and 19b, the photoconductor cartridge B swings downward by its own weight around the second guided portions 71a and 71g supported by the guide members 19a and 19b.
As described later, a drive shaft support member 1 that supports a drive side end portion of the photoconductor cartridge B and a non-drive side support member 12 that supports anon-drive side end portion of the photoconductor cartridge B are provided on the apparatus body A. Regarding the position of the photoconductor cartridge B in the insertion direction D, a range in which the guide members 19a and 19b can support the first guided portions 73e and 71h partially overlaps with a range in which the drive shaft support member 1 and the non-drive side support member 12 can support the photoconductor cartridge B. Actually, the range in which the drive shaft support member 1 and the non-drive side support member 12 can support the photoconductor cartridge B refers to a range in which second support portions 1b and 12b of the respective support members 1 and 12 can support supported portions 73d and 71f of the photoconductor cartridge B in
Accordingly, in a state where the first guided portions 73e and 71h have gotten apart from the guide members 19a and 19b, the photoconductor cartridge B will be in a state supported by the drive shaft support member 1 and the non-drive side support member 12 on the downstream side of the insertion direction D. In this state, the second guided portions 71a and 71g are supported by the guide members 19a and 19b at a side upstream of the insertion direction D. Then, when the photoconductor cartridge B is further inserted and reaches a predetermined attachment position with respect to the apparatus body A, the photoconductor cartridge B is positioned with respect to the apparatus body A and in a state coupled to a driving source of the apparatus body A (
Next, an attachment and detachment configuration of the developing cartridge C will be described. As illustrated in
As illustrated in
The driven-side configuration has been described above, but the supporting surface 18e and the position regulating portion 18f on the non-drive side adopt a similar configuration. That is, as illustrated in
In a state where the operator moves the tray 18 in the insertion direction D1, the developing cartridge C may receive force in the draw-out direction D2 from a member provided on the apparatus body A. Even in such a case, the first regulating surfaces 18c and 18h of the tray 18 press the regulated portions 20b and 20f of the developing cartridge C, by which the developing cartridge C moves integrally with the tray 18 in the insertion direction D1. Further, in a state where the operator moves the tray 18 in the draw-out direction D2, the developing cartridge C may receive force in the insertion direction D1 from a member provided on the apparatus body A. Even in such a case, the second regulating surfaces 18d and 18i of the tray 18 press the regulated portions 20b and 20f of the developing cartridge C, by which the developing cartridge C moves integrally with the tray 18 in the draw-out direction D2.
According to the present embodiment, a configuration example has been illustrated where the regulated portions 20b and 20f are protruded and the position regulating portions 18b and 18f are fit to the regulated portions 20b and 20f, but other configurations can be adopted to regulate relative movement of the developing cartridge C with respect to the tray 18. For example, one or more projected portions that protrude upward from a bottom surface of the tray 18 can be provided, and the developing cartridge C can be provided with recessed portions that fit to the projected portions. Even in this case, the projected portions fits to the recessed portions to regulate relative movement of the developing cartridge C to the insertion direction D1 and the draw-out direction D2 with respect to the tray 18, and the developing cartridge C can be moved along with the insertion or drawing out of the tray 18. Further, configurations corresponding to the position regulating portions 18b and 18f and the regulated portions 20b and 20f can be provided at arbitrary positions that differ from the illustrated positions in a plane coordinate of the tray 18. Similar effects can be achieved by this configuration.
As illustrated in
As illustrated in
Thereafter, the developing cartridge C loaded on the tray 18 is inserted in the insertion direction D1 so as to be attached to the apparatus body A. As described earlier, the photoconductor cartridge B is configured to be attached to and detached from the apparatus body A in a state where the developing cartridge C is not attached. Therefore, the attachment operation of the developing cartridge C is normally performed in a state where the photoconductor cartridge B has been attached to the apparatus body A.
Supporting Configuration of Cartridge
Next, a supporting configuration of the photoconductor cartridge B and the developing cartridge C in a state attached to the apparatus body A will be described. While being attached to the apparatus body A, the photoconductor cartridge B is supported by the driven-side plate 15 and the non-driven-side plate 16 (
As illustrated in
Further, as illustrated in
Next, a supporting configuration of the developing cartridge C will be described. As illustrated in
As illustrated in
As described above, the developing cartridge C is inserted together with the tray 18 to the apparatus body A in the insertion direction D in a state being placed on the tray 18. As illustrated in
The inclined surface 23c is inclined with respect to a horizontal plane so as to extend upward in the vertical direction toward a downstream side in the insertion direction D. Therefore, if the developing cartridge C is further inserted after the inclined surface 23c contacts the coupling pin 69, the inclined surface 23c rides on the coupling pin 69 and the developing cartridge C lifts up. Then, as illustrated in
In the state where the first support hole 23a and the second support hole 23b are engaged with the coupling pin 69, at least a portion of the weight of the developing cartridge C will be supported by the photoconductor cartridge B through the coupling pin 69. The developing cartridge C is capable of swinging in a direction in which the developing roller 32 moves toward and away from the photosensitive drum 62 while the coupling pin 69 acting as a fulcrum. As illustrated in
In a state where the developing cartridge C moves by having the inclined surface 23c of the first support hole 23a and the second support hole 23b ride on the coupling pin 69, the coupling pin 69 pushes back the inclined surface 23c, by which a force opposite to the insertion direction D acts on the developing cartridge C. However, as described above, since the first regulating surfaces 18c and 18h of the position regulating portions 18b and 18f provided on the tray 18 push the regulated portions 20b and 20f of the developing cartridge C in the insertion direction D, the developing cartridge C can move to the insertion direction D together with the tray 18. The fitting length in the up-down direction of the first regulating surfaces 18c and 18h and the regulated portions 20b and 20f is set so that the first regulating surfaces 18c and 18h maintain contact with the regulated portions 20b and 20f even in a state where the inclined surface 23c rides on the coupling pin 69.
When drawing out the tray 18, in a state where the coupling pin 69 is withdrawn from the first support hole 23a and the second support hole 23b, a force in the insertion direction D that is opposite to the draw-out direction acts on the developing cartridge C. However, as described above, the second regulating surfaces 18d and 18i of the position regulating portions 18b and 18f provided on the tray 18 push the regulated portions 20b and 20f of the developing cartridge C in the draw-out direction, the developing cartridge C can move to the draw-out direction together with the tray 18. The fitting length in the up-down direction of the second regulating surfaces 18d and 18i and the regulated portions 20b and 20f is set so that the second regulating surfaces 18d and 18i maintain contact with the regulated portions 20b and 20f while the coupling pin 69 is withdrawn from the first support hole 23a and the second support hole 23b.
As described, according to the present embodiment, the attachment and detachment of the photoconductor cartridge B is guided by the guide members 19a and 19b and the attachment and detachment of the developing cartridge C is performed in a state supported by the tray 18. Then, by inserting the tray 18 supporting the developing cartridge C in a direction intersecting the reference axis direction X, that is, the insertion direction D, the developing cartridge C is engaged with the photoconductor cartridge B attached to the apparatus body A. That is, the replacement operation of the cartridges is facilitated in a configuration where the image forming unit is composed of a plurality of cartridges, and an image forming unit and an image forming apparatus having a high usability can be provided.
In the present embodiment, the urging member 100 is provided on the tray 18, but the urging member can be arranged at a different location, as long as it is arranged to apply force in a direction abutting the developing roller against the photosensitive drum. The trench shape of the first support hole 23a and the second support hole 23b is preferably somewhat inclined with respect to the horizontal plane so that it rises in the vertical direction as it extends upstream in the insertion direction D, as according to the present embodiment. Thereby, it becomes possible to prevent respective support holes engaged to the coupling pin 69 from slipping out of the coupling pin 69. Furthermore, it becomes possible to prevent slipping even further by arranging the position of the developing cartridge C in a state where the first support hole 23a and the second support hole 23b are engaged with the coupling pin 69 so that the first support hole 23a urges the coupling pin 69 by gravity acting on the developing cartridge C.
Further, the urging member 100 should preferably be rounded at the end portion on the upstream side in the insertion direction D of the tray 18. Thereby, the developing cartridge C can easily ride on the urging member 100 along with the operation for inserting the tray 18 to the apparatus body A.
According to the present embodiment, the developing cartridge C is designed to ride on the urging member 100 along with the insertion operation of the tray 18, but as another example, the urging member may urge the developing cartridge C by performing a predetermined operation after the insertion operation of the tray 18. For example, an opening portion through which the urging member 100 can pass may be formed on the bottom surface of the tray 18, and at the same time, the urging member 100 may be designed to move in linkage with the opening and closing of the door 13 (
Input of Drive to Cartridge
Next, a configuration for entering drive (driving force) from the apparatus body A to the photoconductor cartridge B will be described. As illustrated in
The drum coupling 70 and the developing coupling 21 adopt a configuration where they can both be inclined with respect to the photoconductor cartridge B and the developing cartridge C, in other words, so that the rotational axis of the coupling member can be inclined with respect to the reference axis direction X. As described below, the drum coupling 70 and the developing coupling 21 are configured to be engaged with or withdrawn from the first drive shaft 14 and the second drive shaft 99 along with the operation in which the photoconductor cartridge B and the developing cartridge C are inserted to and drawn out of the apparatus body A.
As illustrated in
Similarly, as illustrated in
In the state illustrated in
Positioning of Photosensitive Drum in Axial Direction
Next, a configuration for positioning the photoconductor cartridge B with respect to the reference axis direction X will be described. As illustrated in
Further, a regulation member 2 having a regulation groove 2a is provided on the apparatus body A. The regulation groove 2a functions as a regulation portion that is provided on the apparatus body to regulate the cartridge position in the reference axis direction X in a state where the photoconductor cartridge B is attached to the apparatus body A. The regulation groove 2a is a trench-shaped groove that extends in a substantially vertical direction and opens upstream in the insertion direction D of the cartridge.
As illustrated in
When the photoconductor cartridge B moves further to the insertion direction D, as illustrated in
A clearance between the guide groove 1c and the protruded portion 74 in the reference axis direction X is not necessarily matched with a clearance between the regulation groove 2a and the regulated portion 61 in the reference axis direction X. For example, the positioning accuracy of the photosensitive drum 62 during image forming operation may be improved by setting the former value smaller than the latter value. Further according to the present embodiment, the part used for positioning during attachment of cartridge, that is, the guide groove 1c and the protruded portion 74, is provided individually from apart used for positioning in the state where the cartridge is attached, that is, the regulation groove 2a and the regulated portion 61, but they can be arranged collectively. For example, it may be possible to extend the guide groove 1c to reach the area of the cutout portion 1d according to the present embodiment to enable the protruded portion 74 to be engaged to the guide groove 1c even in the state where the cartridge is attached.
Removal of Cartridge
The photoconductor cartridge B and the developing cartridge C can be removed from the apparatus body A by performing a removal operation of carrying out the steps of attachment operation described above in reverse order. In order to remove the developing cartridge C, the operator draws out the tray 18 to an opposite direction to the insertion direction D in a state where the door 13 of the apparatus body A is opened. Then, the first support hole 23a and the second support hole 23b are withdrawn from the coupling pins 69 and 69 and engagement between the developing cartridge C and the photoconductor cartridge B is cancelled. Further, the developing coupling 21 is withdrawn from the second drive shaft 99 of the apparatus body A. By lifting up the developing cartridge C from the tray 18 in a state where the tray 18 is drawn out to the predetermined position, removal of the developing cartridge C is completed. Thereafter, the operator may further remove the photoconductor cartridge B or set a new developing cartridge C to the tray 18 so that only the developing cartridge C is replaced.
In the present embodiment, service life of the photoconductor cartridge B is set longer than an average period of time for toner sealed in a new developing cartridge C to be consumed. Therefore, only the developing cartridge C can be replaced if there is no need to replace the photoconductor cartridge B.
When removing the photoconductor cartridge B, the operator draws out the photoconductor cartridge B to a direction opposite to the insertion direction D in a state where the developing cartridge C has been removed. Then, the photoconductor cartridge B is withdrawn from the drive shaft support member 1 and the non-drive side support member 12 on the apparatus body A, and the drum coupling 70 is withdrawn from the first drive shaft 14. Thereafter, the cartridge is drawn out further along the guide members 19a and 19b, by which the removal of the photoconductor cartridge B from the apparatus body A is completed.
Conveyance of Waste Toner
Next, a configuration for conveying waste toner collected by the cleaning member from the photosensitive drum will be explained.
The first screw 86 is arranged near the photosensitive drum 62 and the cleaning member 77 so that a rotational axis thereof extends in the reference axis direction X (refer to
A waste toner discharge port 72a serving as a first opening portion capable of discharging waste toner to the developing cartridge C is provided on the lid member 72. The waste toner discharge port 72a is provided at a position opposing to a downstream portion of the second screw 87 in the conveyance direction of the second screw 87. Waste toner removed from the photosensitive drum 62 by the cleaning member 77 is first conveyed by the first screw 86 along the reference axis direction X, then conveyed by the second screw 87 to the waste toner discharge port 72a and discharged to an exterior of the photoconductor cartridge B.
Further, a shutter not shown is provided respectively on the waste toner discharge port 72a of the photoconductor cartridge B and the waste toner receiving port 23d of the developing cartridge C. In a state where the photoconductor cartridge B and the developing cartridge C are attached to the apparatus body A, the shutters are in an opened state, so that the waste toner discharge port 72a and the waste toner receiving port 23d are communicated. In a state where the photoconductor cartridge B and the developing cartridge C are separated, such as when the developing cartridge C is removed from the apparatus body A, both shutters are closed to prevent waste toner from leaking to the exterior.
An actual configuration example of such shutter mechanism will be described below. A shutter member capable of sliding in the insertion direction D is arranged on the casing of each cartridge, and an urging member for urging each shutter to a position closing the opening portion is arranged. Then, during an insertion operation of the developing cartridge C, a portion of the developing cartridge C slides the shutter of the photoconductor cartridge B in the insertion direction D to open the waste toner discharge port 72a. Along therewith, a portion of the photoconductor cartridge B may slide the shutter of the developing cartridge C to a direction opposite to the insertion direction D to open the waste toner receiving port 23d. As for the waste toner receiving port 23d of the developing cartridge C that faces upward, it may be in an opened state without providing a shutter thereto.
Next, an image forming apparatus according to a second embodiment will be described. The present embodiment differs from the first embodiment in that a photoconductor cartridge is inserted to the apparatus body in a state supported by a drawer member other than the tray 18 described above. Components having a similar configuration and effect as those of the first embodiment are denoted with the same reference numbers as the first embodiment, and descriptions thereof are omitted.
As illustrated in
As illustrated in
As illustrated in
The operation of attaching the photoconductor cartridge B and the developing cartridge C to the apparatus body A that follows is the same as the first embodiment. That is, by inserting the upper tray 101 supporting the photoconductor cartridge B to the apparatus body A toward the insertion direction D, the drum coupling 70 is connected to the first drive shaft 14 of the apparatus body A (
Further, if the developing cartridge C is inserted to the apparatus body A in a state where the photoconductor cartridge B is attached to the apparatus body A, the first support hole 23a and the second support hole 23b of the developing cartridge C fit to the coupling pins 69 and 69 of the photoconductor cartridge B (
According to the present embodiment, the attachment and detachment of the photoconductor cartridge B and the developing cartridge C are performed in a state where the cartridges are supported by trays (18 and 101). By inserting the tray 18 supporting the developing cartridge C in a direction intersecting the reference axis direction X, that is, in the insertion direction D, the developing cartridge C is engaged with the photoconductor cartridge B attached to the apparatus body A. That is, even according to the configuration of the present embodiment, the replacement operation of the cartridges is facilitated in a configuration where the image forming unit is composed of a plurality of cartridges, and an image forming unit and an image forming apparatus having a high usability can be provided.
Next, an image forming apparatus according to a third embodiment will be described. Configurations similar to the first and second embodiments are denoted with the same reference numbers as the first and second embodiments, and descriptions thereof are omitted.
First, drive transmission between a photoconductor cartridge B serving as a first cartridge and a developing cartridge C serving as a second cartridge according to the present embodiment will be described with reference to
As described earlier, the process unit PU is detachably attached to the apparatus body A, and includes the photoconductor cartridge B and the developing cartridge C. The photoconductor cartridge B and the developing cartridge C are inserted to the apparatus body A.
The driving force from the apparatus body A is transmitted via a first drive shaft 14 (refer to
The developing cartridge C includes a developing coupling gear 310 that rotates integrally with the developing coupling 21. The developing coupling gear 310 is configured to be coaxial with the developing coupling 21 in a state in which the developing coupling 21 is engaged with the second drive shaft 99.
A developing roller gear 311 is attached to the developing roller 32. A first conveyance gear 315 is attached to the first conveyance member 43. A second conveyance gear 316 is attached to the second conveyance member 44. A third conveyance gear 318 is attached to the third conveyance member 50. A third screw gear 320 is attached to the third screw 88.
Further, the developing cartridge C includes a first idler gear 312, i.e., drive transmission portion according to the present embodiment, meshed with the developing coupling gear 310, a second idler gear 313 meshed with the first idler gear 312, and a third idler gear 314 meshed with the second idler gear 313. The third idler gear 314 is meshed with the first conveyance gear 315 and the second conveyance gear 316. Further, the developing cartridge C includes a fourth idler gear 317 meshed with the second conveyance gear 316 and the third conveyance gear 318, and a fifth idler gear 319 meshed with the third conveyance gear 318 and the third screw gear 320. The first idler gear 312 is rotatable around a rotational axis, i.e., second rotational axis. The rotational axis directions of the respective gears are parallel.
Meanwhile, in the photoconductor cartridge B, a first screw gear 323 is attached to the first screw 86. Further, the photoconductor cartridge B includes a driven gear 321, i.e., driven portion according to the present embodiment, meshed with the first idler gear 312, and an intermediate gear 322 meshed with the driven gear 321 and the first screw gear 323. The driven gear 321 is rotatable around a rotational axis, i.e., first rotational axis.
The drum coupling 70 receives drive from the apparatus body A and rotates in an arrow R direction together with the photosensitive drum 62. The photosensitive drum 62 is configured to transmit drive to the transfer roller 7 (refer to
Further, the developing coupling gear 310 rotates in an arrow SS direction of
Driving force is transmitted sequentially from the first idler gear 312 to the second idler gear 313 and the third idler gear 314. In a state where the third idler gear 314 rotates, the first conveyance gear 315 and the second conveyance gear 316 rotate. Driving force is further transmitted from the second conveyance gear 316 to the fourth idler gear 317, the third conveyance gear 318, the fifth idler gear 319 and the third screw gear 320. Thereby, driving force is transmitted from the apparatus body A to the developing roller gear 311, the first conveyance member 43, the second conveyance member 44, the third conveyance member 50 and the third screw 88.
As described earlier, the developing cartridge C is capable of being separated from the photoconductor cartridge B. Further, the developing cartridge C is attached to and detached from the apparatus body A in a state where the photoconductor cartridge B has been attached to the apparatus body A. More specifically, the first support hole 23a and the second support hole 23b of the developing cartridge C are engaged with the coupling pin 69 provided on the cleaning frame member 71. Thereby, the developing cartridge C is coupled to the photoconductor cartridge B.
In a state where the photoconductor cartridge B and the developing cartridge C are attached to the apparatus body A, the first idler gear 312 is directly meshed with the driven gear 321 provided in the photoconductor cartridge B. The first idler gear 312 transmits the driving force that the developing coupling 21 receives from the apparatus body A to the driven gear 321.
The driving force transmitted to the driven gear 321 rotates the intermediate gear 322 and is transmitted via the intermediate gear 322 to the first screw gear 323. Then, the first screw gear 323 and the first screw 86 rotate.
In other words, according to the present embodiment, the first screw 86 serving as an example of a rotary member is rotated by the driving force input to the developing coupling 21.
Meanwhile, the photosensitive drum 62 provided on the photoconductor cartridge B similarly as the first screw 86 is rotated by the driving force transmitted to the drum coupling 70, as described earlier. In other words, both a member, e.g., the photosensitive drum 62, that rotates by driving force transmitted via the first input portion and a member, e.g., the first screw 86, that rotates by driving force transmitted via the second input portion provided on the second cartridge exist in the first cartridge according to the present embodiment.
As mentioned earlier, the second screw 87 rotates by receiving driving force from the first screw 86. Waste toner removed by the cleaning member 77 from the photosensitive drum 62 is first conveyed by the first screw 86 along the reference axis direction X and thereafter conveyed by the second screw 87 to the waste toner discharge port 72a, before being discharged to the exterior of the photoconductor cartridge B.
Method for Engaging Driven Gear and First Idler Gear
Next, a method for engaging the driven gear 321 of the photoconductor cartridge B and the first idler gear 312 of the developing cartridge C will be described with reference to
As described in the first embodiment, the developing cartridge C moves in the direction of arrow D and is inserted in the apparatus body A. The developing cartridge C is supported by the apparatus body A via the photoconductor cartridge B. More specifically, the insertion direction D, that is, direction of attachment, of the developing cartridge C is a direction intersecting a rotational axis of the first idler gear 312. In the present embodiment, the direction of insertion of the developing cartridge C is a direction orthogonal to the rotational axis of the first idler gear 312. Further, the direction of attachment, i.e., direction of insertion, of the photoconductor cartridge B is a direction intersecting the rotational axis of the driven gear 321. In the present embodiment, the direction of attachment of the photoconductor cartridge B is a direction orthogonal to the rotational axis of the driven gear 321. Further, the rotational axis of the first idler gear 312 is parallel to the rotational axis of the driven gear 321. Further, the rotational axis direction of the first idler gear 312 is in parallel with the rotational axis direction of the developing roller 32. Further, the rotational axis direction of the first idler gear 312 is parallel with the direction of a pivot axis of the developing cartridge C described later.
As described earlier, in a state where the developing cartridge C is inserted to the apparatus body A, the first support hole 23a and the second support hole 23b of the developing cartridge C is engaged with the coupling pin 69 provided on the cleaning frame member 71, and the developing cartridge C is coupled to the photoconductor cartridge B. The developing cartridge C is supported pivotably in an arrow CD direction by the photoconductor cartridge B. Further, when the developing cartridge C pivots in the arrow CD direction around the coupling pin 69, the gap retainer 38 (refer to
Thereby, the position of the developing cartridge C with respect to the photoconductor cartridge B is regulated in a direction orthogonal to the rotational axis direction of the first idler gear 312.
In this state, as illustrated in
In a state where the developing cartridge C is attached in the arrow D direction, the first idler gear 312 of the developing cartridge C is engaged with the driven gear 321. In the present embodiment, at least a part of the driven gear 321 is exposed from the photoconductor cartridge B toward the upstream side in the insertion direction D, i.e., attachment direction, of the developing cartridge C. Further, at least a portion of the first idler gear 312 is exposed from the developing cartridge C toward the downstream side in the insertion direction D of the developing cartridge C. Further, with respect to the insertion direction D of the developing cartridge C, a center of rotation, i.e., rotational axis, of the driven gear 321 is positioned downstream of the center of rotation, i.e., rotational axis, of the first idler gear 312. Thereby, in a state where the developing cartridge C is inserted in the arrow D direction, the first idler gear 312 of the developing cartridge C is engaged smoothly with the driven gear 321.
As illustrated in
In the arrow CD direction, that is, the direction in which the developing roller 32 approaches the photosensitive drum 62, the direction of force FD should preferably be directed toward the downstream side of a line FP connecting an action part of force FD and a center of the coupling pin 69. The action part of force FD represents a portion in which tooth surfaces 312b of the first idler gear 312 contact tooth surfaces 321b of the driven gear 321. If the direction of force FD satisfies the above-described relationship, the force FD generated by the mutual pushing of the tooth surfaces 312b and 321b when the first idler gear 312 rotates the driven gear 321 causes a moment in the arrow CD direction to act on the developing cartridge C. Therefore, the gap retainer 38 of the developing cartridge C can be abutted against the photosensitive drum 62 more securely. Similar to the first embodiment, the developing cartridge C can be urged toward the arrow CD direction by the urging member 100 (
As illustrated in
The position of the developing cartridge C with respect to the direction orthogonal to the rotational axis direction of the first idler gear 312 is determined by the first support hole 23a and the second support hole 23b engaging with the coupling pin 69 and the gap retainer 38 being in contact with the photosensitive drum 62. In other words, the developing cartridge C includes a position determined portion, that is, the first support hole 23a, the second support hole 23b and the gap retainer 38, with respect to the direction orthogonal to the rotational axis direction of the first idler gear 312. Further, the photoconductor cartridge B includes a position determining portion, that is, the coupling pin 69 and the photosensitive drum 62, with respect to the direction orthogonal to the rotational axis direction of the first idler gear 312.
In a direction orthogonal to the rotational axis direction of the first idler gear 312, in a state where the developing cartridge C is positioned, a gap is formed between the tooth tip surfaces 312d of the teeth 312a of the first idler gear 312 and the bottom surfaces 321c of the driven gear 321. Similarly, a gap is formed between the tooth tip surfaces 321d of the teeth 321a of the driven gear 321 and the bottom surfaces 312c of the first idler gear 312.
In other words, the process unit PU according to the present embodiment includes a restriction portion, that is, the coupling pin 69 and the photosensitive drum 62, that restricts movement of the developing cartridge C with respect to the direction orthogonal to the rotational axis of the first idler gear 312. The restriction portion contacts a restricted portion, that is, the first support hole 23a, the second support hole 23b and the gap retainer 38, of the developing cartridge C, and restricts movement of the developing cartridge C. More specifically, the restriction portion restricts movement of the developing cartridge C so that a gap is formed between the tip circle of the teeth 312a of the first idler gear 312 and the root circle of the driven gear 321 when viewed in the rotational axis direction of the first idler gear 312. Further, the restriction portion restricts movement of the developing cartridge C so that a gap is formed between the root circle of the first idler gear 312 and the tip circle of the driven gear 321 when viewed in the rotational axis direction of the first idler gear 312.
The first idler gear 312 and the driven gear 321 are positioned between a first restriction portion, i.e., the coupling pin 69, and a second restriction portion, i.e., the photosensitive drum 62, with respect to the direction orthogonal to the rotational axis of the first idler gear 312. The first idler gear 312 and the driven gear 321 are positioned between a first restricted portion, i.e., the first support hole 23a and the second support hole 23b, and a second restricted portion, i.e., the gap retainer 38.
Thereby, the driven gear 321 and the first idler gear 312 can be meshed stably. At the same time, the mutual positions of the photoconductor cartridge B and the developing cartridge C can be determined highly accurately. Further, the gap retainer 38 can be abutted against the photosensitive drum 62 stably.
Meanwhile, an angle, i.e., narrow angle, formed between a line GG that connects a rotational axis of the first idler gear 312 and a rotational axis of the driven gear 321 and a line FP should preferably be greater than 0° and smaller than 90°. The gap between the bottom surfaces 321c of the driven gear 321 can be secured more reliably if the line GG and the line FP are close to parallel. Further, the driven gear 321 and the first idler gear 312 can be meshed smoothly when the developing cartridge C is inserted if the line GG and the line FP are orthogonal. In the present embodiment, the angle, i.e., narrow angle, formed between line GG and line FP is set greater than 45°.
Further, the force required for the first idler gear 312 to rotate is greater than a force required for the driven gear 321 to rotate. If the driven gear 321 and the first idler gear 312 abut against each other during insertion of the developing cartridge C, the driven gear 321 rotates. As a result, rotation of the developing roller 32 can be prevented.
Conveyance of Waste Toner
Now, conveyance of waste toner by the first screw 86 and the second screw 87 will be described with reference to
The photoconductor cartridge B includes a cleaning frame member 71 and a screw lid 325. The cleaning frame member 71 and the screw lid 325 form a waste toner path 330 through which waste toner removed from the photosensitive drum 62 passes. The first screw 86 and the second screw 87 are arranged on the waste toner path 330.
An end portion of the first screw 86 protrudes out of the waste toner path 330 through a hole formed on the screw lid 325. A D-cut plane 86d is formed at an end portion of the first screw. The first screw gear 323 is attached to the D-cut plane 86d. A sponge-like sealing member (not shown) is arranged at a gap formed between the first screw 86 and the hole on the screw lid 325, preventing leakage of toner from the waste toner path 330.
The first screw 86 includes a transmission portion 86a. The second screw 87 includes a transmitted portion 87a. The transmission portion 86a and the transmitted portion 87a are engaged at an inner side of the waste toner path 330. In a state where the first screw 86 rotates, the transmission portion 86a rotates the transmitted portion 87a. Thereby, driving force is transmitted from the first screw 86 to the second screw 87. The transmission portion 86a and the transmitted portion 87a can be formed, for example, by a pin gear or a bevel gear.
As illustrated in
Meanwhile, the second screw 87 includes a shaft portion and a spiral conveyance portion 87c wound around the shaft portion. The cleaning frame member 71 includes a bearing 71o, and the screw lid 325 includes a bearing 325a. The position of the second screw 87 in a direction orthogonal to a rotational axis 87b is regulated by the bearing 710 and the bearing 325a. By rotation of the second screw 87 around the rotational axis 87b, the waste toner transmitted to the second screw 87 is conveyed in an arrow N direction along the rotational axis 87b through the conveyance portion 87c. The waste toner conveyed by the second screw 87 is discharged through the waste toner discharge port 72a provided on the lid member 72 (refer to
Transmission of Drive from Developing Cartridge to Photoconductor Cartridge
According to the configuration described above, in a configuration where the photoconductor cartridge B is separable from the developing cartridge C, drive can be transmitted from the developing cartridge C to the photoconductor cartridge B, to thereby drive the driven gear 321, the first screw 86 and the second screw 87.
Thereby, force necessary for driving the drum coupling 70 can be reduced.
Further, in the photoconductor cartridge B, there is no need to provide members for transmitting driving force from the drum coupling 70 to the driven gear 321 or the first screw 86 and the second screw 87.
Generally, the number of recording media that can be printed using the photoconductor cartridge B is greater than the number of recording media that can be printed using the developing cartridge C. In the present embodiment, the number of recording media that can be printed by the photoconductor cartridge B is several times the number of recording media that can be printed by the developing cartridge C. In other words, the photoconductor cartridge B can be used longer than the developing cartridge C. That is, a frequency of replacement of the developing cartridge C is higher than a frequency of replacement of the photoconductor cartridge B.
The developing cartridge C must be replaced with a new developing cartridge C when toner is consumed. In contrast, the photoconductor cartridge B can be used until service life of one of the components of the photoconductor cartridge B, such as the photosensitive drum 62 or the charging roller 66, is consumed. In order to increase toner T stored in the developing cartridge C, the size of the developing cartridge must be increased. Meanwhile, service life of the photosensitive drum 62 or the charging roller 66 can be extended by varying materials and so on, without having to increase the size of the photoconductor cartridge B. Further, as described earlier, the photoconductor cartridge B can be used for a longer period of time by collecting waste toner when replacing the developing cartridge C by providing the waste toner chamber 30 in the developing cartridge C.
Meanwhile, the photosensitive drum 62 is designed to contact the recording medium. Therefore, the first screw 86 and the second screw 87 rotate while being in contact with waste toner and paper dusts. Generally, in a state where waste toner and paper dusts exist, wear of the sliding portions between members or at the sealing portion tends to increase. Therefore, if the photoconductor cartridge B having an especially long service life is adopted, it is preferable to reduce the rotation of the first screw 86 or the second screw 87, which are examples of the waste toner conveyance members.
In some cases, the photosensitive drum 62 is rotated to charge the photosensitive drum 62 before the developing roller 32 is rotated. According to the present embodiment, even if the photosensitive drum 62 is rotated before the developing roller 32 is rotated, it becomes possible to prevent the waste toner conveyance member from rotating.
Furthermore, as described earlier, a shutter is respectively provided on the waste toner discharge port 72a of the photoconductor cartridge B and the waste toner receiving port 23d of the developing cartridge C. In a state where the photoconductor cartridge B and the developing cartridge C are separated, the shutters are respectively closed to prevent waste toner from leaking.
If rotation of the first screw 86 and the second screw 87 is allowed in a state where only the photoconductor cartridge B is attached to the apparatus body A, waste toner is conveyed to the waste toner discharge port 72a in a state where the waste toner discharge port 72a is closed by the shutter. However, according to the present embodiment, the first screw 86 and the second screw 87 are rotated by the driving force from the developing cartridge C. Therefore, the first screw 86 and the second screw 87 are not driven unless the photoconductor cartridge B and the developing cartridge C are coupled. Therefore, waste toner can be conveyed to the waste toner discharge port 72a in a state where the waste toner discharge port 72a is opened without fail.
In the third embodiment described above, a gear meshed directly with each other was described as an example of the drive transmission portion and the driven portion, but other drive transmission mechanisms can be used. For example, a dog clutch mutually meshed with one another can be adopted as the drive transmission portion and the driven portion.
According to the third embodiment, the first screw 86 for conveying waste toner was illustrated as an example of a member in the first cartridge, that is, the photoconductor cartridge B, driven by driving force transmitted to the first cartridge via the second cartridge, that is, the developing cartridge C. However, another member, such as the charging roller 66 of
Embodiments described according to the aforementioned embodiments were mere examples for carrying out the present invention, and other modifications are possible within the scope of the technical ideas of the present technique. For example, the image forming unit may include a cartridge other than the photoconductor cartridge B and the developing cartridge C, such as a toner cartridge capable of being detachably attached to the developing cartridge C.
Further, the coupling pin 69 and the first and second support holes 23a and 23b are mere examples of the engagement portion and the engaged portions. Instead of the configuration of the above-illustrated embodiments, for example, a shaft-like member can be provided in the developing cartridge C, and a trench-shaped portion that is engaged with the shaft-like member can be provided in the photoconductor cartridge B. According to the first and second embodiments, the coupling pins 69 and 69 are arranged on both end portions in the reference axis direction X of the photoconductor cartridge B, and the first and second support holes 23a and 23b are arranged on both end portions in the reference axis direction X of the developing cartridge C, but the arrangement of the present invention is not limited thereto. The configuration can include one set of engagement portion and engaged portion, or more than three sets. However, the position or positions at which the engagement portion(s) and the engaged portion(s) engage should preferably be arranged symmetrically with respect to the reference axis direction X.
According to the present embodiment, driving force can be transmitted from the second cartridge to the first cartridge in the image forming unit in which the second cartridge is arranged detachably from the first cartridge.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application Nos. 2019-032129, filed on Feb. 25, 2019, and 2019-189732, filed on Oct. 16, 2019, which are hereby incorporated by reference herein in their entirety.
| Number | Date | Country | Kind |
|---|---|---|---|
| JP2019-032129 | Feb 2019 | JP | national |
| JP2019-189732 | Oct 2019 | JP | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 20080138109 | Anan et al. | Jun 2008 | A1 |
| 20090257781 | Fuji | Oct 2009 | A1 |
| 20100080615 | Kikuchi | Apr 2010 | A1 |
| 20110164897 | Kikuchi | Jul 2011 | A1 |
| 20160070207 | Yada et al. | Mar 2016 | A1 |
| 20160154374 | Hiramatsu et al. | Jun 2016 | A1 |
| 20170108824 | Kawakami et al. | Apr 2017 | A1 |
| 20170248869 | Matsumoto et al. | Aug 2017 | A1 |
| 20170248905 | Anan et al. | Aug 2017 | A1 |
| 20170261917 | Harada et al. | Sep 2017 | A1 |
| 20170329279 | Hirayama et al. | Nov 2017 | A1 |
| 20180267455 | Isaka | Sep 2018 | A1 |
| 20180329359 | Anan et al. | Nov 2018 | A1 |
| 20180348700 | Hirayama et al. | Dec 2018 | A1 |
| 20190179256 | Hirayama et al. | Jun 2019 | A1 |
| 20190361383 | Sato | Nov 2019 | A1 |
| 20200050143 | Hirayama et al. | Feb 2020 | A1 |
| 20200089159 | Sato et al. | Mar 2020 | A1 |
| 20200150582 | Hirayama et al. | May 2020 | A1 |
| 20200201245 | Hirayama et al. | Jun 2020 | A1 |
| 20200201246 | Hirayama et al. | Jun 2020 | A1 |
| 20200201247 | Hirayama et al. | Jun 2020 | A1 |
| 20200201248 | Hirayama et al. | Jun 2020 | A1 |
| 20200201249 | Hirayama et al. | Jun 2020 | A1 |
| 20200241468 | Hirayama et al. | Jul 2020 | A1 |
| 20200272087 | Sueshige et al. | Aug 2020 | A1 |
| Number | Date | Country |
|---|---|---|
| 2002-196585 | Jul 2002 | JP |
| 2009-157389 | Jul 2009 | JP |
| 2010-102285 | May 2010 | JP |
| Number | Date | Country | |
|---|---|---|---|
| 20210216034 A1 | Jul 2021 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 16798618 | Feb 2020 | US |
| Child | 17201148 | US |
