JP2022112702A - drum cartridge - Google Patents

Abstract

To provide a configuration that can peel developer on a magnetic roller while reducing the size in a withdrawal direction of a drum cartridge.SOLUTION: A drum cartridge 50 is movably supported in a first direction with respect to a color printer 1, and the drum cartridge 50 comprises: a first photoconductor drum 51K; a frame 59 that allows the toner cartridge TC to be removably attached in a third direction, the frame 59 having a developer container 62 that stores developer including toner and carrier; a magnetic roller 61 that can carry the developer and faces the first photoconductor drum 51K; and a second auger 64 that faces the magnetic roller 61. The magnetic roller 61 has a first magnetic pole S1 and a second magnetic pole S2 with the same polarity as that of the first magnetic pole S1. The second auger 64 faces a peeling area W between the first magnetic pole S1 and the second magnetic pole S2 in the third direction, and is located between the first magnetic pole S1 and the second magnetic pole S2 in the first direction.SELECTED DRAWING: Figure 5

Description

The present disclosure relates to a drum cartridge mounted on an image forming apparatus.

2. Description of the Related Art Conventionally, a developing unit that can be used in an image forming apparatus is known (Patent Document 1). The developing unit includes a developing container containing developer having toner and carrier, a magnetic roller for supplying the developer in the developing container to the photosensitive drum, and an auger for supplying the developer to the magnetic roller. , provided. In such a development method using a developer containing toner and carrier, it is necessary to peel off the developer on the magnetic roller after development. When the developer container is positioned above the magnetic roller, the developer cannot be separated by gravity. , the developer was peeled off.

As another form of image forming apparatus, there is known a configuration including a body housing, a drum cartridge detachable from the body housing, and a developing cartridge detachable from the drum cartridge (Patent Reference 2). According to this configuration, the drum cartridge has a plurality of photosensitive drums. The drum cartridge is movable in the direction in which the plurality of drums are arranged, between a housed position located inside the body housing and a drawn position pulled out from the body housing. As a result, the user can replace the developing cartridge while the drum cartridge is pulled out, which improves operability.

JP 2006-308624 A JP 2013-76877 A

In the configuration of the drum cartridge that can be attached and detached by pulling it out of the main body housing of Patent Document 2, when the developing unit as in Patent Document 1 is applied, a configuration in which the auger is obliquely arranged with respect to the magnetic roller is conceivable. With such a configuration, there is a problem that the size of the drum cartridge in the pull-out direction becomes large. Therefore, a configuration in which the auger is arranged above the magnetic roller is conceivable. However, the separation on the magnetic roller could not be sufficiently performed only by arranging the auger on the top.

Therefore, it is an object of the present invention to provide a structure capable of peeling off the developer on the magnetic roller while reducing the size of the drum cartridge in the pull-out direction.

A drum cartridge supported movably in a first direction with respect to an image forming apparatus, the drum cartridge comprising a first photosensitive drum rotatable about a first drum shaft extending in the second direction and a first photosensitive drum extending in the second direction. A second photosensitive drum rotatable about a second drum shaft, the second photosensitive drum being aligned with the first photosensitive drum in a first direction, and a toner cartridge accommodating toner in a third direction are detachable frames. a frame having a developer container containing a developer containing toner and carrier; a magnetic roller capable of carrying the developer in the developer container, the magnetic roller facing the photosensitive drum; and an auger shaft extending in the second direction. a rotatable auger facing the magnetic roller; The magnetic roller has a magnetic roller shaft extending in the second direction, and a sleeve positioned around the outer periphery of the magnetic roller shaft and rotatable about the magnetic roller shaft. The magnetic roller shaft is a first magnet having a first magnetic pole, the first magnet positioned with the first magnetic pole facing the sleeve, and the second magnet positioned apart from the first magnet in the rotation direction of the sleeve. a second magnet having a second magnetic pole of the same polarity as the first magnetic pole, the second magnet positioned with the second magnetic pole toward the sleeve. The magnetic roller has a stripping region located between the first magnetic pole and the second magnetic pole in the rotational direction of the sleeve, the stripping region being free of other magnetic poles, and the auger shaft is positioned in the third direction in the stripping region and located between the first magnet and the second magnet in the first direction.

According to this configuration, the size of the drum cartridge in the first direction can be reduced as compared with the case where the second auger is positioned beside the magnetic roller.

Alternatively, a blade may be provided for regulating the layer thickness of the developer on the magnetic roller, and the second magnetic pole may face the blade.

According to this configuration, when the layer thickness is regulated by the blade, the necessary amount of developer can be retained by the second magnetic pole.

Also, in the rotational direction of the magnetic roller, the first point where the magnetic force of the second magnetic pole is maximum may be positioned upstream with respect to the second point that is closest to the blade of the magnetic roller.

According to this configuration, after holding a sufficient amount of the developer in the developing container at the first point, the layer thickness of the developer can be regulated at the second point.

Also, the second magnet may be arranged farther from the auger than the first magnet.

According to this configuration, the auger easily separates the developer from the separation area by agitating the developer.

The developing container has a first arcuate surface facing the first magnetic pole and extends along the sleeve, and the developing container has a second arcuate surface facing the second magnetic pole and extends along the sleeve. and a second arcuate surface, wherein the distance between the second arcuate surface and the sleeve is greater than the distance between the first arcuate surface and the sleeve.

According to this configuration, the developer can be sufficiently accommodated between the second arcuate surface and the sleeve.

Also, the auger has an auger shaft extending in the second direction, and a blade positioned at the recovery of the auger shaft and having a helical shape, and the distance between the tip of the blade and the sleeve is It may be configured to be smaller than the distance between the two arcuate surfaces and the sleeve.

According to this configuration, the developer on the magnetic roller can be easily peeled off by the blades of the auger.

Further, the developer container may have an open end extending from the first arcuate surface and extending away from the magnetic roller.

According to this configuration, the developer on the magnetic roller after development can be prevented from being scraped off by the developing container when entering the developing container as the sleeve rotates.

Also, the rotation direction of the auger may be opposite to the rotation direction of the magnetic roller.

According to this configuration, the auger can agitate the developer toward the second magnetic pole.

Also, the magnetic roller has a third magnet located on the side opposite to the second magnet with respect to the first magnet in the rotation direction of the magnetic roller, and the third magnet is located on the side opposite to the second magnet in the rotation direction of the magnetic roller. and a third magnet located on the opposite side of the auger, the third magnet being a third magnetic pole having a polarity opposite to that of the first magnetic pole, and having a third magnetic pole facing the photosensitive drum, good too.

Also, the magnetic force of the third magnetic pole may be greater than that of the first magnetic pole and the second magnetic pole.

According to this configuration, the third magnetic pole can prevent the carrier from moving to the photosensitive drum when the photosensitive drum is developed.

Further, the auger may be positioned between the toner cartridge and the magnetic roller in the third direction with the toner cartridge attached.

According to this configuration, the toner cartridge mounted on the drum cartridge, the auger, and the magnetic roller are aligned in the third direction, so the size of the drum cartridge in the first direction can be reduced.

The developer on the magnetic roller can be peeled off while reducing the size of the drum cartridge pull-out direction with respect to the magnetic roller.

1 is a sectional view showing a color printer of this embodiment; FIG. FIG. 3 is a cross-sectional view showing a drum cartridge to which a toner cartridge is attached; FIG. 5 is a cross-sectional view showing a state in which the drum cartridge is positioned at the pulled-out position; FIG. 8 is a cross-sectional view of the developing unit viewed from one end side in the third direction; FIG. 5 is a cross-sectional view of the developing unit viewed from the other end side in the second direction; FIG. 10 is a cross-sectional view of the developing unit viewed from the other end side in the second direction, showing the arrangement of the magnetic poles of the magnetic roller and the magnetic force of each magnetic pole in the normal direction. FIG. 2 is a diagram showing the arrangement of magnetic poles of a magnetic roller and the magnetic force of each magnetic pole in the normal direction; 3 is a perspective view of a toner sensor; FIG. 3A and 3B are perspective views of the developing unit as viewed from the magnetic roller side, in which (a) the toner sensor is not covered with an insulating sheet, and (b) the toner sensor is covered with an insulating sheet. 2 is a perspective view showing wiring among a toner sensor, a relay board, and a connector; FIG.

Next, an embodiment of the present disclosure will be described in detail with reference to the drawings as appropriate. In the following description, the direction in which the plurality of photosensitive drums 51 are arranged is defined as the first direction. The axial direction of the photosensitive drum 51 is defined as the second direction. Also, the first direction intersects with the second direction. Preferably, the first direction is orthogonal to the second direction. Also, the direction in which the toner cartridge TC is attached to and detached from the developing unit is defined as the third direction. The third direction intersects the second direction and the first direction. Preferably, the third direction is orthogonal to the second direction and the first direction. In the following description, in the main housing 10, one end side in the third direction is simply called "upper", and the other end side in the third direction is simply called "lower". For example, in FIG. 2 the toner cartridge TC is positioned above the first auger 63 and the magnetic roller 61 is positioned below the second auger 64 .

(1) Overall Description of Color Printer 1 As shown in FIG. 1, a color printer 1 as an example of an image forming apparatus includes a main housing 10, a front cover 11, a main body connector 12, a sheet feeding section 20, It has an image forming section 30 , a discharge section 90 and a control section 100 .

The body housing 10 has an opening 10A. The opening 10A is located on one end side of the main housing 10 in the first direction.

The front cover 11 can move between an open position that opens the opening 10A and a closed position that closes the opening 10A. Specifically, the front cover 11 is rotatable between an open position and a closed position.

The body connector 12 is electrically connected to the controller 100 . The body connector 12 is located inside the body housing 10 .

The sheet supply section 20 includes a supply tray 21 and a sheet transport mechanism 22 . The supply tray 21 accommodates the sheets S. As shown in FIG. The sheet conveying mechanism 22 conveys the sheet S from the supply tray 21 to the image forming section 30 .

The image forming section 30 includes a scanner unit 40 , a drum cartridge 50 , four toner cartridges TC, a transfer member 70 and a fixing device 80 .

The scanner unit 40 includes a laser emitting section, a polygon mirror, a lens, a reflecting mirror, and the like (not shown). The scanner unit 40 emits a laser beam to the photosensitive drum 51 .

The drum cartridge 50 is movable in the first direction with respect to the main housing 10 through the opening 10A.

The drum cartridge 50 is movable in the first direction with respect to the main body housing 10 between an accommodation position located within the main body housing 10 and a drawn position pulled out from the main body housing 10 . The drum cartridge 50 is supported by the main housing 10 so as to be movable between an accommodation position and a drawn-out position. The drum cartridge 50 is removable from the color printer 1 .

As shown in FIG. 2, the drum cartridge 50 includes a plurality of photosensitive drums 51, a plurality of scorotron chargers 52, a plurality of cleaning rollers 53, a frame 59, a plurality of developing units 60, a sheet guide 54, and a connector 55 . Specifically, the drum cartridge 50 includes four photosensitive drums 51, four scorotron chargers 52, four cleaning rollers 53, a frame 59, four developing units 60, a sheet guide 54, and a connector 55. have The four photosensitive drums 51 include a first photosensitive drum 51K, a second photosensitive drum 51C, a third photosensitive drum 51M, and a fourth photosensitive drum 51Y.

The plurality of photosensitive drums 51, the plurality of scorotron chargers 52, the plurality of cleaning rollers 53, and the plurality of developing units 60 form images of different colors (eg, cyan, magenta, yellow, and black). However, in this embodiment, the plurality of photosensitive drums 51, the plurality of scorotron chargers 52, the plurality of cleaning rollers 53, and the plurality of developing units 60 have the same configuration except for the color of the developer used for image formation. . Therefore, only one of the plurality will be described below.

The photosensitive drum 51 is rotatable about a drum axis X1 extending in the second direction. More specifically, the first photosensitive drum 51K is rotatable about the first drum axis X11. The second photosensitive drum 51C is rotatable about a second drum axis X12. The third photosensitive drum 51M is rotatable about a third drum axis X13. The fourth photosensitive drum 51Y is rotatable about a fourth drum axis X14. The multiple photosensitive drums 51 are arranged in the first direction. More specifically, the first photosensitive drum 51K, the second photosensitive drum 51C, the third photosensitive drum 51M, and the fourth photosensitive drum 51Y are arranged in the first direction.

The scorotron charger 52 is a charger that charges the photosensitive drum 51 . A charging roller may be used instead of the scorotron charger 52 .

The cleaning roller 53 is a roller that cleans the photosensitive drum 51 . A cleaning blade may be used instead of the cleaning roller 53 .

The developing unit 60 is positioned between the toner cartridge TC and the photosensitive drum 51 in the third direction. The developing unit 60 includes a magnetic roller 61 , a developer container 62 , a first auger 63 , a second auger 64 and a blade 65 . The second auger 64 is an example of an auger.

The magnetic roller 61 is a roller that supplies toner to the photosensitive drum 51 . The magnetic roller 61 has a magnetic roller shaft 61A and a sleeve 61B.

The magnetic roller shaft 61A is fixed to the developer container 62. As shown in FIG. In other words, the magnetic roller shaft 61A does not rotate with respect to the developer container 62 . A plurality of magnets 610 are arranged on the magnetic roller shaft 61A (see FIG. 5).

The sleeve 61B is made of, for example, a cylindrical member mainly made of a non-magnetic metal material. The sleeve 61B is rotatable around the magnetic roller shaft 61A. The sleeve 61B holds the developer by the magnetic force of the plurality of magnets 610. As shown in FIG. A developing voltage is applied from the main housing 10 to the sleeve 61B.

The magnetic roller 61 is positioned below a first auger 63 and a second auger 64 in the third direction. The magnetic roller 61 is positioned between the toner cartridge TC and the photosensitive drum 51 . The sleeve 61B is rotatable about the magnetic roller axis X2 extending in the second direction. That is, the magnetic roller 61 is rotatable about the magnetic roller axis X2 extending in the second direction. The magnetic roller 61 faces the surface of the photosensitive drum 51 . The magnetic roller 61 is separated from the surface of the photosensitive drum 51 .

The developing container 62 is a container that accommodates non-magnetic toner and magnetic carrier. The carrier is, for example, iron powder. The developer container 62 has a supply port 62A. The supply port 62A is located on the side opposite to the magnetic roller 61 with respect to the first auger 63 and the second auger 64 in the third direction.

The supply port 62A is located above the first auger 63 and the second auger 64 in the third direction. Specifically, the supply port 62A is positioned above the first auger 63 . The magnetic roller axis X2 is positioned below the first auger 63 and the second auger 64 . Specifically, the magnetic roller axis X2 is located below the second auger 64 . When the toner cartridge TC is attached to the developer container 62, toner can be supplied to the developer container 62 from the supply port 62A. The supply port 62A is positioned on one end side of the developer container 62 in the second direction (see FIG. 7).

As shown in FIG. 2, the first auger 63 and the second auger 64 are positioned within the developer container 62 . The first auger 63 is rotatable about a first auger axis X3 extending in the second direction. The second auger 64 is rotatable about a second auger axis X4 extending in the first direction. The first auger 63 is positioned apart from the second auger 64 in the first direction. The first auger 63 is located closer to the supply port 62A than the second auger 64 is.

The blade 65 is a member that regulates the thickness of the toner layer on the magnetic roller 61 . The blade 65 is out of contact with the magnetic roller 61 . The blade 65 is aligned with the magnetic roller 61 in the first direction. The magnetic roller axis X2 is located between the blade 65 and the drum axis X1 in the second direction.

The sheet guide 54 is a guide that guides the sheet S toward the photosensitive drum 51 . The sheet guide 54 is aligned with the photosensitive drum 51 in the first direction. The sheet guide 54 is located upstream of the four photosensitive drums 51 in the sheet S conveying direction.

The most upstream magnetic roller 61 in the sheet S conveying direction is positioned between the sheet guide 54 and the second auger 64 in the third direction. The blade 65 positioned most upstream in the conveying direction of the sheet S is positioned between the sheet guide 54 and the first auger 63 in the third direction.

A connector 55 is located on the outer surface of the drum cartridge 50 . Specifically, the connector 55 is located on the outer surface of the frame that supports the developer unit 60 .

A toner cartridge capable of containing toner can be attached to and detached from the frame 59 in the third direction. The frame 59 has a developer container 62 capable of accommodating a developer containing toner and carrier, which will be described later.

The four toner cartridges TC have the same configuration except for the color of the developer contained therein. Therefore, only one of the plurality will be described below.

The toner cartridge TC contains toner that is non-magnetic. As shown in FIG. 3, the toner cartridge TC can be attached to or removed from the frame 59 of the drum cartridge 50 . Specifically, the toner cartridge TC is detachable from the frame 59 of the drum cartridge 50 in the third direction.

The toner cartridge TC has a toner memory TM. The toner memory TM has a storage element capable of storing information and a contact capable of contacting the first electrical contact 56 described later. The toner memory TM stores toner cartridge information regarding the toner cartridge TC. The toner cartridge information is at least one of identification information that can identify each toner cartridge TC and toner life information of each toner cartridge TC. Identification information is, for example, a serial number. The toner life information is, for example, at least one of the cumulative number of rotations of the magnetic roller 61 or the first auger 63, the used dot count, and the remaining amount of toner.

As shown in FIG. 1, the transfer member 70 is a member that transfers the toner image on the photosensitive drum 51 onto the sheet S. As shown in FIG. The transfer member 70 is positioned between the sheet supply section 20 and the drum cartridge 50 . The transfer member 70 includes a driving roller 71 , a driven roller 72 , a conveying belt 73 and a transfer roller 74 .

The driving roller 71 and the driven roller 72 are spaced apart in the first direction. The driving roller 71 and the driven roller 72 support a conveying belt 73 that is an endless belt. The transfer roller 74 is positioned inside the transport belt 73 . The transfer roller 74 sandwiches the conveying belt 73 with the photosensitive drum 51 .

The fixing device 80 has a heating roller 81 and a pressure roller 82 . The pressure roller 82 sandwiches the sheet S with the heat roller 81 .

A series of operations when the image forming section 30 performs image formation is as follows.

In the image forming section 30 , the scorotron charger 52 charges the surface of the photosensitive drum 51 . After that, the scanner unit 40 forms an electrostatic latent image on the photosensitive drum 51 by exposing the surface of the photosensitive drum 51 .

The magnetic roller 61 supplies developer to the electrostatic latent image formed on the photosensitive drum 51 to form a developer image on the photosensitive drum 51 . After that, the conveying belt 73 conveys the sheet S conveyed from the sheet supply section 20 toward the photosensitive drum 51 . The transfer roller 74 transfers the developer image on the photosensitive drum 51 to the sheet S by pressing the sheet S sandwiched between the conveying belt 73 and the photosensitive drum 51 from the inside of the conveying belt 73 toward the photosensitive drum 51 . do. The fixing device 80 fixes the developer image onto the sheet S by sandwiching the sheet S onto which the developer image has been transferred between a heating roller 81 and a pressure roller 82 .

The discharge section 90 includes a plurality of conveying rollers 91 . The conveying roller 91 discharges the sheet S that has passed through the fixing device to the outside of the main housing 10 .

The control unit 100 includes, for example, a CPU, a RAM, a ROM, and an input/output circuit. to control.

As shown in FIG. 1, the connector 55 is electrically connected to the color printer 1 when the drum cartridge 50 is attached to the color printer 1 . Specifically, the connector 55 contacts and is electrically connected to the body connector 12 when the drum cartridge 50 is attached to the body housing 10 . When the connector 55 is electrically connected to the body connector 12 with the toner cartridge TC attached to the drum cartridge 50, the controller 100 acquires the toner cartridge information from the toner memory TM, or stores the toner cartridge information in the toner memory TM. Information can be written.

(2) Description of Developing Unit 60 (2-1) Description of Developing Container 62 As shown in FIG. The first storage chamber 62B and the second storage chamber 62C communicate with each other through a supply port 62E and a recovery port 62F.

The first accommodation chamber 62B is a space that accommodates the first auger 63 . 62 C of 2nd storage chambers are spaces which accommodate the 2nd auger 64. As shown in FIG. The first containing chamber 62B and the second containing chamber 62C contain toner and carrier therein.

The partition wall 62D extends in the second direction. The partition wall 62D is located between the first auger 63 and the second auger 64. As shown in FIG.

The supply port 62E is positioned on the other end side in the second direction of the partition wall 62D. The supply port 62E allows movement of toner and carrier from the first storage chamber 62B to the second storage chamber 62C.

The recovery port 62F is positioned on one end side in the second direction of the partition wall 62D. The recovery port 62F allows movement of toner and carrier from the second storage chamber 62C to the first storage chamber 62B.

The supply port 62A communicates the first storage chamber 62B and the outside of the developer container 62 with each other. The supply port 62A allows toner to be supplied from the toner cartridge TC. Specifically, when the toner cartridge TC is attached to the developing container 62, the replenishment port 62A includes a first storage chamber 62B, a toner storage chamber (not shown) in which the toner cartridge TC stores toner, communicate. The supply port 62A is positioned closer to the recovery port 62F than the supply port 62E. Specifically, the distance from the supply port 62A to the supply port 62E is greater than the distance from the supply port 62A to the recovery port 62F.

As shown in FIG. 5, the developer container 62 has a magnet sheet 69 . The magnet sheet 69 is positioned at the end of the developer container 62 in the second direction. The magnet sheet 69 faces the magnetic roller 61 .

The developer container 62 has a first arcuate surface 62G that faces a first magnetic pole S1, which will be described later. The first arcuate surface 62G extends along the sleeve 61B of the magnetic roller 61. As shown in FIG. The developer container 62 also has an open end 62I extending from the first arcuate surface 62G. The open end 62I extends away from the magnetic roller 61 .

The developer container 62 has a second arcuate surface 62H that faces a second magnetic pole S2, which will be described later. The second arcuate surface 62H extends along the sleeve 61B of the magnetic roller 61. As shown in FIG.

(2-2) Configuration of First Auger 63 and Second Auger 64 As shown in FIG. 4, the first auger 63 carries toner and carrier from one end 60A of the developing container 62 toward the other end 60B in the second direction. transport. In other words, the first auger 63 conveys toner and carrier from the recovery port 62F toward the supply port 62E. Specifically, the first auger 63 conveys the toner supplied from the supply port 62A to the first storage chamber 62B to the supply port 62E together with the carrier. Further, the first auger 63 conveys the toner and carrier supplied from the recovery port 62F to the first storage chamber 62B to the supply port 62E. The developer transported to the supply port 62E is transported from the first storage chamber 62B to the second storage chamber 62C via the supply port 62E. In other words, the supply port 62</b>E allows the developer transported by the first auger 63 to move toward the second auger 64 .

The first auger 63 has a first auger shaft 63A and first auger blades 63B. The first auger shaft 63A is rotatable about a first auger shaft extending in the second direction. The first auger blade 63B is positioned on the outer circumference of the first auger shaft 63A. The first auger blade 63B has a spiral shape. The first auger 63 does not contact a detection portion 66B of the toner sensor 66, which will be described later. More specifically, the diameter of the tip of the first auger blade 63B is partially reduced so as not to come into contact with the detector 66B.

The second auger 64 conveys toner and carrier from the other end 60B of the developer container 62 in the second direction toward the one end 60A. In other words, the second auger 64 conveys toner and carrier from the supply port 62E toward the collection port 62F. Specifically, the second auger 64 conveys the toner supplied from the supply port 62E to the second storage chamber 62C toward the other end in the second direction together with the carrier. The developer conveyed in the second direction by the second auger 64 adheres to the sleeve 61B of the magnetic roller 61 due to the magnetic force of the magnetic roller 61 . The developer transported to the recovery port 62F is transported from the second storage chamber 62C to the first storage chamber 62B via the recovery port 62F. In other words, the recovery port 62</b>F allows the developer transported by the second auger 64 to move toward the first auger 63 .

The second auger 64 has a second auger shaft 64A and second auger blades 64B. The second auger shaft 64A is rotatable about a second auger shaft extending in the second direction. The second auger blade 64B is positioned on the outer circumference of the second auger shaft 64A. The second auger blade 64B has a spiral shape.

The first auger 63 and the second auger convey and agitate the developer in the developer container 62 at the same time. Agitation of the developer by the first auger 63 and the second auger 64 causes the developer to be triboelectrically charged.

In this manner, the first auger 63 and the second auger 64 can convey toner and carrier from the supply port 62A toward the magnetic roller 61. FIG. Also, the first auger 63 and the second auger 64 circulate the carrier and toner in the developer container 62 .

(2-3) Configuration of Toner Sensor 66 As shown in FIG.

A toner sensor 66 can detect the toner density in the developer container 62 . A signal detected by the toner sensor 66 is sent to the controller 100 (see FIG. 1). Thereby, the controller 100 can determine the amount of toner in the developer container 62 from the signal sent from the toner sensor 66 . The toner sensor 66 of this embodiment is a magnetic permeability sensor capable of detecting magnetic permeability.

A toner sensor 66 is positioned below the first auger 63 . The toner sensor 66 is positioned between the photosensitive drum 51 and the first auger 63 in the third direction. The toner sensor 66 is located on the opposite side of the first auger 63 from the supply port 62A in the third direction. The toner sensor 66 is positioned below the developer container 62 . The toner sensor 66 is positioned below the second auger 64 . The toner sensor 66 is positioned closer to the first auger 63 than to the second auger 64 .

As shown in FIG. 8, the toner sensor 66 has a body portion 66A and a detection portion 66B. The body portion 66A is positioned outside the developer container 62 . As shown in FIG. 9A, the body portion 66A is attached to the developer container 62. As shown in FIG. Also, as shown in FIG. 9B, an insulating sheet 68 is attached to the body portion 66A. The detection portion 66B enters a hole of the developer container 62 and comes into contact with the developer in the developer container 62 . More specifically, the detection section 66B contacts the developer in the first storage chamber 62B. Note that the toner sensor 66 may be located obliquely below the first auger 63 as long as a sufficient amount of developer is present in the vicinity of the detection portion 66B.

The toner sensor 66 is positioned away from the supply port 62A in the second direction. Specifically, the supply port 62A is located closer to the recovery port 62F than the supply port 62E, while the toner sensor 66 is located closer to the supply port 62E than the recovery port 62F. As a result, the toner sensor 66 can detect the developer after the toner replenished through the replenishment port 62A and the developer present in the developer container 62 are sufficiently agitated.

(2-4) Configuration of Frame 59 As shown in FIG. 10, the drum cartridge 50 has a frame 59 that supports the photosensitive drum 51 and the developing unit 60 . The frame 59 has a third side plate W3, a fourth side plate W4, a front plate W5, and a rear plate W6. The third side plate W3, the fourth side plate W4, the front plate W5 and the rear plate W6 are made of resin.

Each developing unit 60 is positioned between the third side plate W3 and the fourth side plate W4 in the second direction. The front plate W5 is positioned on one end side in the first direction of the third side plate W3 and the fourth side plate W4. The rear plate W6 is positioned on the other end side in the first direction of the third side plate W3 and the fourth side plate W4.

(2-5) Configuration of Relay Board 58 The drum cartridge 50 further includes a first electrical contact 56, a second electrical contact 57, a relay board 58, wiring CA1, and wiring CA2.

More specifically, drum cartridge 50 includes a plurality of first electrical contacts 56 . Each first electrical contact 56 corresponds to each of the plurality of toner memories TM. The first electrical contacts 56 are arranged side by side in the second direction inside the fourth side plate W4. When the toner cartridge TC is attached to the drum cartridge 50 and the drum cartridge 50 is attached to the main housing 10, the first electrical contact 56 is in contact with the toner memory TM, thereby being electrically connected to the toner memory TM. be.

The drum cartridge 50 also has a plurality of second electrical contacts 57 . Each second electrical contact 57 corresponds to each of the plurality of toner sensors 66 . The second electrical contacts 57 are arranged side by side in the second direction inside the fourth side plate W4. When the drum cartridge 50 is attached to the main housing 10 , the second electrical contact 57 contacts the output contact of the toner sensor 66 and is thereby electrically connected to the toner sensor 66 .

The relay board 58 is located on the inner surface of the rear plate W6 of the drum cartridge 50. As shown in FIG. The relay board 58 has a drum memory 58M that stores drum cartridge information about the drum cartridge 50 . Specifically, the drum memory 58M is located on the relay board. The relay board 58 is electrically connected to the first electrical contact 56 and the second electrical contact 57 by the wiring CA1. Also, the relay board 58 is electrically connected to the connector 55 by the wiring CA2. The relay board 58 electrically connects each toner sensor 66 and the connector 55 . The relay board 58 electrically connects each toner memory TM and the connector 55 . The drum memory 58M is electrically connected to the connector 55 by a wiring CA2.

The drum cartridge information is at least one of identification information that can identify the drum cartridge 50 and drum life information of the photosensitive drum 51 . Identification information is, for example, a serial number. The drum life information is, for example, at least one of the cumulative number of rotations of the photosensitive drum 51, the cumulative number of printed sheets using the photosensitive drum 51, and the cumulative dot count number using the photosensitive drum 51. FIG.

A signal detected by the toner sensor 66 is communicated to the controller 100 of the color printer 1 via the relay board 58 .

The toner cartridge information stored in the toner memory TM is communicated to the controller 100 of the color printer 1 via the relay board 58 .

The information stored in the drum memory 58M is communicated to the control section 100 of the color printer 1. FIG.

(3) Configuration of Magnetic Roller 61 (3-1) Description of Magnet 610 of Magnetic Roller 61 As shown in FIG. In other words, the second auger 64 is positioned between the toner cartridge TC and the magnetic roller 61 . The magnetic roller 61 rotates in the direction of arrow A1. The direction of rotation of the magnetic roller 61 is opposite to the direction of rotation of the second auger 64 (arrow A2).

Magnetic roller 61 has a plurality of magnets 610 . A plurality of magnets 610 are fixed to the magnetic roller shaft 61A. Specifically, the plurality of magnets 610 are adhered to the magnetic roller shaft 61A with an adhesive. A plurality of magnets 610 are spaced apart on the magnetic roller shaft 61A in the direction of rotation of the sleeve 61B. Specifically, the first magnet 611, the second magnet 612, the third magnet 613, the fourth magnet 614, and the fifth magnet 615 are positioned at intervals on the magnetic roller shaft 61A. The first magnet 611 is positioned with the first magnetic pole S1 facing the sleeve 61B. The second magnet 612 is positioned with the second magnetic pole S2 facing the sleeve 61B. The third magnet 613 is positioned with the third magnetic pole N1 facing the sleeve 61B. The fourth magnet 614 is positioned with the fourth magnetic pole N2 facing the sleeve 61B. The fifth magnet 615 is positioned with the fifth magnetic pole S3 facing the sleeve 61B. Therefore, the magnetic roller 61 has a first magnetic pole S1, a second magnetic pole S2, a third magnetic pole N1, a fourth magnetic pole N2 and a fifth magnetic pole S3. The magnetic force distribution in the normal direction of the magnetic roller 61 formed by each magnetic pole is as shown in FIGS. 6 and 7. FIG. 6 and 7, the illustration of the magnet 610 is omitted, and the magnetic force distribution and the arrangement of the magnetic poles that form the magnetic field shown in the magnetic force distribution are shown only by reference numerals. 5, 6, and 7, of the magnetic poles of each magnet 610, the magnetic poles having the opposite polarity to the magnetic poles described above and not shown face the magnetic roller shaft 61A.

5 and 6, the first magnet 611 faces the first circular arc surface 62G of the developer container 62. As shown in FIGS. More specifically, the first magnetic pole S1 faces the first arcuate surface 62G of the developing container 62. As shown in FIG. In this embodiment, the first magnetic pole S1 is the S pole.

The second magnet 612 is positioned apart from the first magnet 611 in the rotation direction of the magnetic roller 61 . Therefore, the second magnetic pole S2 is positioned apart from the first magnetic pole S1 in the direction of rotation of the magnetic roller 61 . The second magnetic pole S2 is positioned downstream of the first magnetic pole S1 in the direction of rotation of the magnetic roller 61 . The second magnetic pole S2 faces the second arcuate surface 62H of the developer container 62. As shown in FIG. Also, the second magnetic pole S2 faces the blade 65 . A first point P at which the magnetic force of the second magnetic pole S2 in the normal direction of the magnetic roller 61 is maximized is located upstream from a second point Q closest to the blade 65 of the magnetic roller 61 . The second magnetic pole S2 has the same polarity as the first magnetic pole S1. In this embodiment, the second magnetic pole S2 is the S pole.

The second magnetic pole S2 is adjacent to the first magnetic pole S1. In other words, there is no other magnetic pole between the first magnetic pole S1 and the second magnetic pole S2 in the direction of rotation of the magnetic roller 61 . As a result, almost no magnetic force exists in a region between the first magnetic pole S1 and the second magnetic pole S2 where no other magnetic pole exists (hereinafter referred to as a separation region W) (see FIG. 7). The developer is peeled off from the magnetic roller 61 in the peeling area W. As shown in FIG. The second magnet 612 is positioned farther from the second auger 64 than the first magnet 611 . Therefore, the second magnetic pole S2 is located farther from the second auger 64 than the first magnetic pole S1. As a result, the separation area W is wider on the downstream side than on the upstream side in the rotation direction of the magnetic roller 61 with respect to the proximity point between the second auger 64 and the magnetic roller 61 .

The third magnet 613 is positioned upstream of the first magnet 611 in the rotation direction of the magnetic roller 61 . Therefore, the third magnetic pole N1 is positioned upstream of the first magnetic pole S1 in the direction of rotation of the magnetic roller 61 . The third magnet 613 is located below the first magnet 611 and the second magnet 612 in the third direction. In other words, the third magnet 613 is located on the opposite side of the second auger 64 with respect to the first and second magnets in the third direction. The third magnetic pole N1 is located below the first magnetic pole S1 and the second magnetic pole S2 in the third direction. The third magnetic pole N1 faces the photosensitive drum 51 . The magnetic force of the third magnetic pole N1 is the largest among the plurality of magnets 610. FIG. Specifically, the magnetic force of the third magnetic pole N1 is greater than the magnetic forces of the first magnetic pole S1, the second magnetic pole S2, the fourth magnetic pole N2, and the fifth magnetic pole S3. The polarity of the third magnetic pole N1 is opposite to that of the first magnetic pole S1. In this embodiment, it is the N pole.

A third point R located between the third magnetic pole N1 and the first magnetic pole S1, where the magnetic force in the normal direction to the sleeve 61B of the magnetic roller 61 is approximately 0, is located in the third direction. , is located at substantially the same position as the lower end of the open end 62I.

The fourth magnetic pole N2 is positioned downstream of the second magnetic pole S2 in the direction of rotation of the magnetic roller 61 . The fourth magnetic pole N2 is located below the blade 65. As shown in FIG. The fourth magnetic pole N2 is positioned below the lower end of the developer container 62 . The fourth magnetic pole N2 is of opposite polarity to the second magnetic pole S2. In this embodiment, it is the N pole.

The fifth magnetic pole S3 is positioned downstream of the fourth magnetic pole N2 in the direction of rotation of the magnetic roller 61 . Also, the fifth magnetic pole S3 is adjacent to the fourth magnetic pole N2 and the third magnetic pole N1. The fifth magnetic pole is located below the third magnetic pole N1 and the fourth magnetic pole N2. The fifth magnetic pole is of opposite polarity to the fourth magnetic pole N2. In this embodiment, it is the S pole.

The magnetic roller 61 conveys the developer in the developer container 62 to the photosensitive drum 51 by each magnet 610 . The process of conveying the developer to the photosensitive drum 51 will be described below.

The magnetic roller 61 holds the developer in the developer container 62 near the second magnetic pole S2 by the magnetic force of the second magnetic pole S2. As the magnetic roller 61 rotates, the developer held by the second magnetic pole S2 passes through a position close to the blade 65 and is regulated in layer thickness. After that, the developer is held by the magnetic roller 61 by the fourth magnetic pole N2 and the fifth magnetic pole S3 and moves toward the position where the magnetic roller 61 and the photosensitive drum 51 are close to each other. At the close position, the developer held by the magnetic roller 61 forms a magnetic brush by the magnetic field of the third magnetic pole N1. As a result, the developer brought to the adjacent position by the magnetic roller 61 comes into contact with the photosensitive drum 51, and the electrostatic latent image on the photosensitive drum 51 is developed. At this time, the nonmagnetic toner moves to the photosensitive drum 51 due to the potential difference, but the magnetic carrier remains on the magnetic roller 61 due to the magnetic force of the third magnetic pole N1. After that, the carrier that has not moved to the photosensitive drum 51 and the toner that has not been developed are held by the magnetic roller 61 by the magnetic force of the first magnetic pole S1 and carried into the developer container 62 . The magnetic brush on the magnetic roller 61 when passing the third point R is in a state along the sleeve 61B of the magnetic roller 61 because the magnetic force in the normal direction is almost zero. After that, the developer carried to the separation area W between the first magnetic pole S1 and the second magnetic pole S2 is not subjected to the magnetic force from the magnetic roller 61, so that the developer inside the developer container 62 being stirred by the second auger 64 It is separated from the magnetic roller 61 by the flow of the developer. As a result, the developing unit 60 separates the developer, whose toner concentration has decreased after passing the position close to the magnetic roller 61 and the photosensitive drum 51 , from the magnetic roller 61 and agitates the developer in the developer container 62 . can be done.

Note that, in the present embodiment, the developer in the developer container 62 is filled above the rotation shaft of the second auger 64 . As a result, since the amount of developer in the second storage chamber 62C is large, even if the developer with reduced toner concentration is stirred with the developer in the developer container 62, the toner concentration in the developer container 62 does not decrease. can reduce the impact.

(3-2) Relationship Between Magnet 610 and Second Auger 64 The second auger 64 is located between the first magnet 611 and the second magnet 612 in the first direction. More specifically, the second auger axis X4 is located between the first magnet 611 and the second magnet 612 in the first direction. Therefore, the second auger 64 is located between the first magnetic pole S1 and the second magnetic pole S2 in the first direction. The second auger axis X4 is located between the first magnetic pole S1 and the second magnetic pole S2 in the first direction.

The first magnetic pole S1 is positioned closer to the second auger 64 than the second magnetic pole S2. In other words, the distance between the second magnetic pole S2 and the second auger 64 is greater than the distance between the first magnetic pole S1 and the second auger 64. As a result, the size of the peeling region W is larger downstream of the magnetic roller 61 in the rotation direction than the close position of the second auger 64 and the magnetic roller 61 .

(3-3) Relationship Between Magnet 610 and Developing Container 62 The distance L1 between the second arcuate surface 62H and the sleeve 61B of the magnetic roller 61 is the distance between the first arcuate surface 62G and the sleeve 61B of the magnetic roller 61. Larger than L2. Therefore, more developer is accommodated between the second arcuate surface 62H and the sleeve 61B than between the first arcuate surface 62G and the sleeve 61B.

The second auger 64 faces the peeling area W. As shown in FIG. Since the flow of the developer conveyed by the second auger 64 scrapes off the developer on the separation area W, the distance between the second auger 64 and the magnetic roller 61 needs to be small to some extent. Specifically, the distance L3 between the tip of the second auger blade 64B of the second auger 64 and the sleeve 61B of the magnetic roller 61 is the distance L1 between the second circular arc surface 62H and the sleeve 61B of the magnetic roller 61. less than

(4) Effects According to the embodiment of the present disclosure described above, the second auger 64 is positioned between the first magnetic pole S1 and the second magnetic pole S2 in the first direction. The developer on the magnetic roller 61 can be peeled off. In addition, since the second auger 64 is positioned above the magnetic roller 61 in the first direction, compared to the case where the second auger 64 is positioned laterally of the magnetic roller 61, the movement of the drum cartridge 50 in the first direction is reduced. size can be reduced. This reduces the amount of pulling out the drum cartridge 50 by the user, so that the operability is good.

Further, since the second magnetic pole S2 faces the blade 65, when the layer thickness of the developer on the magnetic roller 61 is regulated by the blade 65, the developer is held by the second magnetic pole S2. can hold the amount of developer needed for development. Thereby, the magnetic roller 61 can develop an appropriate amount of developer onto the photosensitive drum 51 .

Further, since the first point P is positioned upstream from the second point Q, the magnetic roller 61 holds a sufficient amount of developer in the developer container 62 at the first point P, and then the blade 65 is moved to the first point. It is possible to regulate the layer thickness of the developer at two points Q. Thereby, the magnetic roller 61 can develop an appropriate amount of developer onto the photosensitive drum 51 .

In addition, since the distance between the second magnetic pole S2 and the second auger 64 is larger than the distance between the first magnetic pole S1 and the second auger 64, the separation region W between the second auger 64 and the second magnetic pole S2 The width is also large. As a result, the second auger 64 agitates the developer toward the second magnetic pole S<b>2 to create a flow of the developer, so that the developer on the separation area W can be separated from the magnetic roller 61 . As a result, the developing unit 60 can return the developer whose toner density has decreased after development into the developer container 62 .

Further, since the distance L2 between the second arcuate surface 62H and the sleeve 61B of the magnetic roller 61 is greater than the distance L1 between the first arcuate surface 62G and the sleeve 61B of the magnetic roller 61, the second magnetic pole S2 A sufficient amount of developer can be supplied to the In addition, since the distance L1 between the first arcuate surface 62G and the sleeve 61B of the magnetic roller 61 is sufficiently small, the developer in the developer container 62 can be prevented from leaking out of the developer container 62. FIG.

Further, since the distance L3 between the tip of the second auger blade 64B and the sleeve 61B of the magnetic roller 61 is smaller than the distance L2 between the second arcuate surface 62H and the sleeve 61B of the magnetic roller 61, the second The auger 64 can strip the developer on the magnetic roller 61 and located between the magnetic pole S1 and the magnetic pole S2. As a result, the developing unit 60 can separate the developer whose toner concentration has decreased after development from the magnetic roller 61 .

Further, since the opening end 62I of the developer container 62 extends away from the magnetic roller 61, the developer on the magnetic roller 61 after development can be prevented from being scraped off by the opening end 62I. This can prevent the developer after development from being separated from the magnetic roller 61 at the opening of the developer container 62 . Further, since the distance L1 between the first arcuate surface 62G and the magnetic roller 61 is sufficiently small, the developer in the developer container 62 can be prevented from leaking out of the developer container 62 .

In addition, since the position of the third point R where the magnetic brush of the developer lies down is substantially the same in the third direction as the lower end of the opening end 62I, the developer after development on the magnetic roller 61 can be suppressed from being scraped off by the open end 62I. This prevents the developer on the magnetic roller 61 from peeling off outside the developer container 62 and the developer from adhering to the paper being conveyed and the photosensitive drum 51 .

In addition, since the rotation direction (A2) of the second auger 64 is opposite to the rotation direction (A1) of the magnetic roller 61, the second auger 64 and the magnetic roller 61 do not rotate at the locations where the second auger 64 and the magnetic roller 61 face each other. transport the developer in the same direction. As a result, the second auger 64 agitates the developer toward the second magnetic pole S2, so that the second auger 64 can agitate the developer in the vicinity of the second magnetic pole S2. Further, since the second auger 64 agitates the developer toward the second magnetic pole S2, the second magnetic pole S2 can hold a sufficient amount of developer.

In addition, since the magnetic force of the third magnetic pole N1 is greater than the magnetic forces of the first magnetic pole S1 and the second magnetic pole S2, even if the third magnetic pole is positioned below the developer container, the developer does not reach the magnetic roller 61. It can reduce falling from

In addition, since the magnetic force of the third magnetic pole N1 is greater than the magnetic forces of the first magnetic pole S1 and the second magnetic pole S2, even if the third magnetic pole is positioned below the developer container, the developer does not reach the magnetic roller 61. It can reduce falling from

Further, since the second auger 64 is positioned between the toner cartridge TC and the magnetic roller 61, compared to the case where the second auger 64 and the magnetic roller 61 are arranged side by side in the first direction, the drum cartridge 50 is can be reduced in size in the first direction. As a result, the amount by which the user pulls out the drum cartridge 50 is further reduced, resulting in good operability.

Further, the developer container 62 has the magnet sheet 69 at the end in the second direction, thereby suppressing the developer in the developer container 62 from leaking out of the developer container 62 from the end of the developer container 62 . can.

(5) Modifications Although one embodiment of the present disclosure has been described above, the present disclosure is not limited to the above-described embodiment, and can be implemented with appropriate modifications.

Also, in the above-described embodiment, the polarities of the first magnetic pole and the second magnetic pole are S poles, but they may be N poles. In this case, the third and fourth magnetic poles should be S poles, and the fifth magnetic pole should be N poles.

Also, in the above-described embodiment, the magnetic roller 61 has five magnetic poles, but it may have more or less. For example, in addition to the third and fourth magnetic poles, two more magnetic poles may be provided between the second and third magnetic poles.

Further, in the above-described embodiment, the toner sensor is a magnetic sensor capable of detecting magnetic permeability, but it may be a physical sensor that detects the amount of toner or stirring torque. It may be an optical sensor that detects

Also, in the above-described embodiment, the blade is made of metal, but it may be made of resin.

Further, in the embodiment described above, the drum memory stores drum cartridge information, but may store information detected by a toner sensor. The drum memory may also store values for calibration.

Moreover, each element described in the above-described embodiment and modification can be implemented in combination as appropriate.

10 main housing 50 drum cartridge 51 photosensitive drum 51K first photosensitive drum 51C second photosensitive drum 60 developing unit 61 magnetic roller 61A magnetic roller shaft 61B sleeve 611 first magnet 612 second magnet 613 third magnet S1 first magnetic pole S2 second 2 magnetic poles N1 3rd magnetic pole 62 developer container 62A supply port 62E supply port 62F recovery port 63 first auger 64 second auger 65 blade TC toner cartridge

Claims (11)

A drum cartridge supported movably in a first direction with respect to an image forming apparatus,
a first photosensitive drum rotatable about a first drum shaft extending in a second direction;
a second photosensitive drum rotatable about a second drum shaft extending in the second direction, the second photosensitive drum being aligned with the first photosensitive drum in the first direction;
a frame to which a toner cartridge containing toner is attachable and detachable in a third direction, the frame having a developer container containing developer containing toner and carrier;
a magnetic roller capable of carrying the developer in the developer container and facing the first photosensitive drum;
an auger rotatable about an auger shaft extending in the second direction, the auger facing the magnetic roller;
The magnetic roller is
a magnetic roller shaft extending in the second direction;
a rotatable sleeve located on the outer periphery of the magnetic roller shaft;
The magnetic roller shaft is
a first magnet having a first magnetic pole, the first magnet positioned with the first magnetic pole facing the sleeve;
a second magnet positioned apart from the first magnet in the rotation direction of the sleeve, the second magnet having a second magnetic pole having the same polarity as the first magnetic pole, the second magnetic pole being attached to the sleeve; a second magnet positioned facing;
has
the magnetic roller has a peeling area located between the first magnetic pole and the second magnetic pole in the rotational direction of the sleeve, the peeling area having no other magnetic poles;
The drum cartridge, wherein the auger shaft faces the peeling area in the third direction and is positioned between the first magnet and the second magnet in the first direction. comprising a blade for regulating the layer thickness of the developer on the magnetic roller,
2. The drum cartridge of claim 1, wherein the second magnetic pole faces the blade. A first point at which the magnetic force of the second magnetic pole in the normal direction in the rotational direction of the magnetic roller is maximum is located upstream with respect to a second point of the magnetic roller that is closest to the blade. 3. A drum cartridge as claimed in claim 2. 4. A drum cartridge according to claim 2, wherein said second magnet is located farther from said auger than said first magnet. the developer container has a first arcuate surface facing the first magnetic pole, the first arcuate surface along the sleeve;
The developer container is a second arcuate surface facing the second magnetic pole, is a second arcuate surface along the sleeve, and is positioned between the blade and the first arcuate surface in the rotation direction of the sleeve. and a second arcuate surface that
3. A first distance between said second arcuate surface and said sleeve is greater than a second distance between said first arcuate surface and said sleeve. 5. A drum cartridge according to any one of claims 4 to 4. The auger
an auger shaft extending in the second direction;
a blade located on the outer circumference of the auger shaft, the blade having a helical shape;
6. The drum cartridge according to claim 5, wherein a third distance between the tips of the blades and the sleeve is smaller than the second distance. 7. The drum cartridge according to claim 5, wherein said developer container has an open end extending from said first arcuate surface and extending away from said magnetic roller. 8. A drum cartridge according to any one of claims 1 to 7, wherein the rotating direction of said auger is opposite to the rotating direction of said magnetic roller. The magnetic roller shaft includes a third magnet located on the side opposite to the second magnet with respect to the first magnet in the rotation direction of the magnetic roller, wherein the first magnet and the a third magnet located on the opposite side of the auger relative to the second magnet;
9. The third magnet according to claim 1, wherein the third magnet has a third magnetic pole having a polarity opposite to that of the first magnetic pole, and has a third magnetic pole facing the first photosensitive drum. 1. The drum cartridge according to item 1. 10. The drum cartridge of claim 9, wherein the magnetic force of the third magnetic pole is greater than the magnetic forces of the first magnetic pole and the second magnetic pole. 11. The apparatus according to any one of claims 1 to 10, wherein the auger is positioned between the toner cartridge and the magnetic roller in the third direction when the toner cartridge is attached to the frame. The image forming apparatus according to any one of the items.

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