JP4604715B2 - Developing device and image forming apparatus - Google Patents

Description

  The present invention relates to a developing device and an image forming apparatus.

2. Description of the Related Art Conventionally, a developing device having a developing roller and a supply roller for supplying toner to the developing roller has been provided as used in an image forming apparatus such as a laser printer. For example, Patent Document 1 discloses a technique in which a frame portion is provided below the developing roller and the supply roller along the peripheral surfaces of these rollers so that the toner can be properly supplied to the developing roller.
JP 2004-118093 A

  By the way, in the conventional developing apparatus as described above, a configuration capable of refilling toner is widely used. When refilling toner, if old toner remains in the developing device, it will adversely affect the image quality after refilling. Remove (collect) the oldest toner from the developing device as much as possible, and then fill with new toner. There must be. However, the conventional configuration has a problem that it is difficult to collect the toner that has entered the gap formed by the developing roller, the supply roller, and the frame portion when an attempt is made to refill the toner. That is, the developing device has a tendency that the developing roller, the supply roller, and the frame portion are arranged close to each other with high density due to functional factors and a request for downsizing. Therefore, the toner is easily clogged between these parts, and it is difficult to quickly and sufficiently collect the toner from within the developing device.

  The present invention has been made based on the above-described circumstances, and an object thereof is to easily realize a configuration capable of satisfactorily collecting toner.

As means for achieving the above object, the invention according to claim 1 is a developing device that is detachably provided in the main body of the image forming apparatus, and develops the electrostatic latent image with a powder toner to make it visible. A developing roller facing the image carrier, a supply roller for supplying the powdered toner to the developing roller, and the powdered toner are accommodated so that the developing roller and the supply roller are rotatable. A frame portion for supporting, and at the time of image formation, a distance between the outer peripheral surface of the supply roller and the outer peripheral surface of the developing roller is set in advance at a position where the supply roller and the developing roller face each other. with a first distance, said feed roller, said be relatively immovable with respect to the developing roller, at the time of non-image formation, before Kiko plant, outside of the developing roller and the outer peripheral surface of the feed roller Wherein the distance between the surfaces, from the first distance, so that the larger second distance greater than the first distance, that the supply roller is movable relative to the developing roller And

  According to a second aspect of the present invention, in the developing device according to the first aspect, the frame portion has a facing surface disposed to face the outer peripheral surface of the supply roller, and the supply roller is relatively to the development roller. According to the movement, the distance between the facing surface of the frame portion and the outer peripheral surface of the supply roller is a fourth distance that is larger than the third distance from a preset third distance. It is changed as follows.

According to a third aspect of the present invention, there is provided a developing device which is detachably provided on the main body of the image forming apparatus and develops the electrostatic latent image with a powder toner so as to make it visible. A roller, a supply roller for supplying the powder toner to the developing roller, and a frame portion for storing the powder toner and rotatably supporting the developing roller and the supply roller, The portion has a facing surface disposed to face the outer peripheral surface of the supply roller, and a distance between the facing surface of the frame portion and the outer peripheral surface of the supply roller is set to a preset third distance during image formation. the distance it becomes, the supply roller, be relatively immovable with respect to the facing surface, at the time of non-image formation, the distance between the outer peripheral surface of the supply roller and the opposing surface of the frame portion, the third From distance As a third fourth distance greater than the distance, the feed roller, characterized in that it is movable relative to the facing surface.

According to a fourth aspect of the present invention, in the developing device according to any one of the first to third aspects, the supply roller is relatively movable after the developing device is detached from the main body. And

According to a fifth aspect of the present invention, in the developing device according to any one of the first to fourth aspects, the shaft member of the supply roller passes through the frame portion, and a tip portion of the shaft member is The operation unit is configured to relatively move the supply roller.

According to a sixth aspect of the present invention, in the developing device according to the fifth aspect , a first gear is attached to the shaft member of the supply roller, and the frame portion meshes with the first gear. A detachable second gear for transmitting a driving force to the first gear is arranged, and the engagement between the first gear and the second gear is released during the non-image formation. Thus, the operation unit can be operated.

According to a seventh aspect of the present invention, in the developing device according to the sixth aspect , the operation is performed by removing only the second gear of the first gear and the second gear during the non-image formation. The unit is operable.

According to an eighth aspect of the present invention, in the developing device according to the sixth aspect , the operation unit can be operated by removing both the first gear and the second gear during the non-image formation. It is characterized by that.

According to a ninth aspect of the present invention, in the developing device according to any of the fifth to eighth aspects, the frame portion includes a guide portion that guides the shaft member of the supply roller.

A tenth aspect of the present invention is the developing device according to the ninth aspect , wherein the frame portion has both side walls disposed opposite to each other in the axial direction of the supply roller, and the shaft member of the supply roller is The guide portions are provided on the both side walls of the frame portion, respectively, so as to penetrate the both side walls and be supported by the side walls.

According to an eleventh aspect of the present invention, in the developing device according to the ninth or tenth aspect , the guide portion is formed in a groove shape, and a detachable cap that closes at least a part of the guide portion during image formation. In the non-image formation, the cap member is removed from the guide portion, so that the shaft member can be moved according to the guide portion.

According to a twelfth aspect of the present invention, in the developing device according to the eleventh aspect , the guide portion is provided with a support surface that supports an outer surface of the cap member, and the cap member includes the support surface and an outer surface of the cap. It attaches to the said guide part in the state which interposed the sheet-like sticking medium in between.

According to a thirteenth aspect of the present invention, in the developing device according to any one of the first to twelfth aspects, the supply roller is configured to contact the developing roller during image formation.

According to a fourteenth aspect of the present invention, in the image forming apparatus, the developing device according to any one of the first to thirteenth aspects is provided.

According to a fifteenth aspect of the present invention, in the image forming apparatus, an image carrier, a developing roller facing the image carrier, a supply roller for supplying the powder toner to the developer roller, and the powder toner are accommodated. A frame portion that rotatably supports the developing roller and the supply roller, respectively, and an outer peripheral surface of the supply roller and the development at a position where the supply roller and the developing roller face each other during image formation. the distance between the outer peripheral surface of the roller, it becomes the first preset distance, the supply roller, wherein the relative immovable relative to the developing roller, at the time of non-image formation, before Ki箇 plants, the the distance between the outer peripheral surface of the outer peripheral surface of the supply roller and the developing roller, so that the greater than the first of the first distance from the distance the second distance, the feed roller, the current Characterized in that it is movable relative to the roller.

According to a sixteenth aspect of the present invention, there is provided an image carrier, a developing roller facing the image carrier, a supply roller for supplying the powder toner to the developer roller, the powder toner, and a frame portion which rotatably supports the said feed roller, respectively, wherein the frame portion has a facing surface which is opposed to the outer peripheral surface of the feed roller, during image formation, the counter of the frame part The distance between the surface and the outer peripheral surface of the supply roller is a third distance set in advance, and the supply roller is not allowed to move relative to the facing surface. the distance between the facing surface and the outer peripheral surface of the supply roller, so that the third greater than the third distance from the length of the fourth distance, the feed roller, with respect to the facing surface Relative movement possible Characterized in that it is a.

<Inventions of Claims 1 and 15 >
According to the first and fifteenth aspects, the supply roller and the development roller can be arranged with high density. On the other hand, when collecting the powder toner, the distance between the development roller and the supply roller is increased. Therefore, it is possible to recover the toner in a state where the powder toner is not easily clogged. In addition, it is possible to stably form the supply rollers with high density and perform image formation. On the other hand, during non-image formation, the powder toner can be recovered satisfactorily.

<Invention of Claim 2 >
According to the configuration of the second aspect, since the supply roller can be separated from both the developing roller and the frame portion by the relative movement of the supply roller, the vicinity of the supply roller is more widely released, and the powder toner Can be more effectively prevented.

<Inventions of Claims 3 and 16 >
According to the configurations of claims 3 and 16 , the supply roller and the frame portion can be arranged with high density. On the other hand, when collecting the powder toner, the outer peripheral surface of the supply roller and the opposing surface of the frame portion are arranged. Therefore, the toner can be collected well in a state where the powder toner is not easily clogged. In addition, it is possible to stably form the supply rollers with high density and perform image formation. On the other hand, during non-image formation, the powder toner can be recovered satisfactorily.

<Invention of Claim 4 >
According to the configuration of the fourth aspect , since the supply roller can be relatively moved after the developing device is detached from the apparatus main body, the operator can perform the relative movement operation of the supply roller in a wide space outside the apparatus main body. In addition, it is easy to collect powder toner. Therefore, it becomes the structure which was further excellent in operativity.

<Invention of Claim 5 >
According to the structure of Claim 5 , it becomes a suitable structure which an operator can operate an operation part and can move a supply roller.

<Invention of Claim 6 >
According to the configuration of the sixth aspect , the driving force can be reliably transmitted from the second gear to the first gear attached to the shaft member during image formation, and the first gear and the second gear can be transmitted during non-image formation. By releasing the meshing with the gear, the supply roller can be moved favorably.

<Invention of Claim 7 >
According to the configuration of the seventh aspect , the driving force can be reliably transmitted from the second gear to the first gear during image formation, and the supply roller can be easily moved during non-image formation.

<Invention of Claim 8 >
According to the configuration of the eighth aspect , the driving force can be reliably transmitted from the second gear to the first gear during image formation, and the supply roller can be moved without much complicated operation during non-image formation. This is a preferable example.

<Invention of Claim 9 >
According to the structure of Claim 9 , it becomes the structure which can move the shaft member of a supply roller stably.

<Invention of Claim 10 >
According to the configuration of the tenth aspect , since the guide portions are respectively provided on both side walls of the frame portion, more stable movement is possible.

<Invention of Claim 11 >
According to the configuration of the eleventh aspect , since a part of the guide portion can be closed by the cap member at the time of image formation, leakage of the powder toner from the guide portion can be prevented. Further, in such a configuration, when the non-image is formed, since the shaft member can be moved according to the guide portion by removing the cap member, the moving operation can be facilitated.

<Invention of Claim 12 >
According to the structure of the twelfth aspect , the separation of the cap member can be effectively prevented by the adhesion force of the adhesion medium, and the gap between the outer surface of the cap member and the support surface is filled by the adhesion medium, and the toner Leakage can be prevented.

<Invention of Claim 13 >
According to the configuration of the thirteenth aspect , it is a preferable configuration for supplying the powder toner from the supply roller to the developing roller. In such a high-density configuration, when the supply roller is relatively movable, Useful.

<Invention of Claim 14 >
According to the fourteenth aspect , an image forming apparatus having the same effect as the structure according to any one of the first to thirteenth aspects is obtained.

Next, Embodiment 1 of the present invention will be described.
(1. Overall configuration)
FIG. 1 is a cross-sectional side view of a main part showing an embodiment of a laser printer as an image forming apparatus of the present invention. FIG. 2 is a diagram illustrating a state where the process cartridge is removed from the main body of the laser printer. FIG. 3 is a side view showing the process cartridge with the developing cartridge removed, and FIG. 4 is a side view showing the process cartridge with the developing cartridge attached.

  The laser printer 1 according to the present embodiment includes a main body casing 2, a feeder unit 4 for feeding a sheet 3 as a recording medium housed in the main body casing 2, and a fed sheet 3. An image forming unit 5 for forming an image is provided.

  An attachment / detachment opening 6 for attaching / detaching a process cartridge 20 described later is formed on one side wall of the main casing 2, and a front cover 7 for opening / closing the attachment / detachment opening 6 is provided. The front cover 7 is rotatably supported by a cover shaft (not shown) inserted through the lower end portion thereof. Thus, when the front cover 7 is closed around the cover shaft, the attachment / detachment port 6 is closed by the front cover 7 as shown in FIG. 1, and when the front cover 7 is opened (tilted) with the cover shaft as a fulcrum, As shown in FIG. 2, the attachment / detachment opening 6 is opened, and the process cartridge 20 can be attached / detached to / from the apparatus main body 1 a through the attachment / detachment opening 6. In the laser printer 1, the main body portion other than the process cartridge 20 is the apparatus main body 1a.

  In the following description, the side on which the front cover 7 is provided in FIG. 1 is referred to as “front side”, and the opposite side is referred to as “rear side”. In the present embodiment, the front-rear direction is described as the X-axis direction, the + X direction is described as the “front side”, and the −X direction is described as the “rear side”. The height direction is the Y direction, the upper direction is the + Y direction, and the lower direction is the -Y direction. Furthermore, the direction orthogonal to the X-axis direction and the Y-axis direction is defined as the width direction of the laser printer 1, and this is indicated as the Z-axis direction (see FIG. 7).

  The feeder unit 4 includes a paper feed tray 9 that is detachably attached to the bottom of the main casing 2, a paper feed roller 10 and a separation pad 11 that are provided above the front end of the paper feed tray 9, and a paper feed roller 10, a pickup roller 12 provided on the rear side of the paper feed roller 10, a pinch roller 13 disposed oppositely on the lower front side of the paper feed roller 10, a paper dust removing roller 8 disposed oppositely on the upper front side of the paper feed roller 10, And a registration roller 14 provided on the upper rear side of the roller 10.

  Inside the paper feed tray 9 is provided a paper pressing plate 15 on which the paper 3 can be stacked. The sheet pressing plate 15 is supported so as to be swingable at the rear end portion, so that the front end portion is disposed below, the placement position along the bottom plate 16 of the sheet feeding tray 9 and the front end portion are disposed above. It can be swung to an inclined transport position.

  A lever 17 for lifting the front end portion of the paper pressing plate 15 upward is provided at the front end portion of the paper feed tray 9. The lever 17 is formed in a substantially L-shaped cross section so as to go from the front side to the lower side of the paper pressing plate 15, and its upper end is attached to a lever shaft 18 provided at the front end of the paper feed tray 9. The rear end portion is in contact with the front end portion of the lower surface of the paper pressing plate 15. Accordingly, when a clockwise rotational driving force in the drawing is input to the lever shaft 18, the lever 17 rotates about the lever shaft 18, and the rear end portion of the lever 17 lifts the front end portion of the paper pressing plate 15. The paper pressing plate 15 is positioned at the transport position.

  When the sheet pressing plate 15 is positioned at the transport position, the sheet 3 on the sheet pressing plate 15 is pressed by the pickup roller 12 and is directed between the sheet feeding roller 10 and the separation pad 11 by the rotation of the pickup roller 12. The transport is started.

  On the other hand, when the paper feed tray 9 is detached from the main casing 2, the front end of the paper pressing plate 15 moves downward due to its own weight, and the paper pressing plate 15 is positioned at the placement position. When the paper pressing plate 15 is positioned at the mounting position, the paper 3 can be stacked on the paper pressing plate 15.

  When the sheet 3 sent out between the sheet feeding roller 10 and the separation pad 11 by the pickup roller 12 is sandwiched between the sheet feeding roller 10 and the separation pad 11 by the rotation of the sheet feeding roller 10. Each sheet is reliably fed and fed. The fed paper 3 passes between the paper feed roller 10 and the pinch roller 13, and after the paper dust is removed by the paper dust removing roller 8, it is conveyed to the registration roller 14.

  The registration roller 14 is composed of a pair of rollers, and after the registration of the sheet 3 between the photosensitive member 29 (the photosensitive member 29 corresponds to an image carrier) and a transfer roller 32 described later, 29 is conveyed to a transfer position where the toner image on 29 is transferred to the sheet 3.

  The image forming unit 5 includes a scanner unit 19, a process cartridge 20, a fixing device 21, and the like.

  The scanner unit 19 is provided in the upper part of the main casing 2 and includes a laser light source (not shown), a polygon mirror 22 that is driven to rotate, an fθ lens 23, a reflecting mirror 24, a lens 25, a reflecting mirror 26, and the like. The laser beam based on the image data emitted from the laser light source is deflected by the polygon mirror 22 as shown by a chain line, passes through the fθ lens 23, then the optical path is turned back by the reflecting mirror 24, and further passes through the lens 25. After that, the optical path is further bent downward by the reflecting mirror 26, so that the surface of the drum main body 34 of the photosensitive member 29 described later of the process cartridge 20 is irradiated.

  The process cartridge 20 is detachably attached to the main body casing 2 below the scanner unit 19. The process cartridge 20 includes an upper frame 27 and a lower frame 28 formed separately from the upper frame 27 and combined with the upper frame 27 as a casing. The process cartridge 20 includes a photoconductor 29, a scorotron charger 30 (hereinafter also simply referred to as a charger 30), a developing cartridge 31, a transfer roller 32, and a cleaning brush 33 in a casing.

  The photoconductor 29 has a cylindrical shape and the outermost layer is formed of a positively chargeable photoconductive layer made of polycarbonate or the like, and an axial center of the drum main body 34 along the longitudinal direction of the drum main body 34. An extending metal drum shaft 35 is provided. The drum shaft 35 is supported by the upper frame 27, and the drum body 34 is rotatably supported with respect to the drum shaft 35, so that the photoconductor 29 can rotate about the drum shaft 35 in the upper frame 27. Is provided.

  The scorotron charger 30 is supported by the upper frame 27 and is disposed opposite to the photoconductor 29 at a predetermined interval so as not to come into contact with the photoconductor 29 at an obliquely upper rear side of the photoconductor 29. The scorotron charger 30 is provided between the discharge wire 37, the wall portion opposed to the photosensitive member 29 in the axial direction at a predetermined interval, and the discharge wire 37 and the photosensitive member 29. And a grid electrode 38 for controlling the amount of discharge from the toner to the photoconductor 29. In the scorotron charger 30, a bias voltage is applied to the grid electrode 38, and simultaneously, a high voltage is applied to the discharge wire 37 to cause corona discharge of the discharge wire 37, so that the surface of the photoreceptor 29 is uniformly positive. Can be electrically charged.

  The scorotron charger 30 is provided with a later-described wiper 36 for cleaning the discharge wire 37 so as to sandwich the discharge wire 37.

  As shown in FIG. 3, the upper frame 27 provided in the process cartridge 20 is integrally provided with a left side wall 54, a right side wall (not shown), and an upper wall 56. As shown in FIGS. 3 and 4, the left side wall 54 extends in the width direction of the drum body 34 (the axial direction of the photoconductor 29 and the Z-axis direction perpendicular to the X-axis direction and the Y-axis direction (see FIG. 7)) A left lower plate 57 and a left lower plate facing from one side (hereinafter, this one side in the width direction is the left side (−Z direction (FIG. 7), the other side in the width direction is the right side (+ Z direction (FIG. 7))) An extending plate portion 58 and a left upper plate portion 59 extending upward from the right end edge of the extending plate portion 58 are provided.

  In addition, the drum shaft 35 of the photosensitive member 29 is supported through the respective bearing members arranged on the left and right sides (only the left bearing member 66 is shown in FIG. 3). It protrudes outward in the left-right direction from the bearing member, and stopper members 78 are fitted on both ends thereof. The stopper member 78 prevents the drum shaft 35 from coming off. In FIG. 3, the bearing member 66 and the stop member 78 provided on the left side are shown, but the same bearing member and stop member are provided on the right side to prevent the removal. The end of the drum shaft 35 protruding from the left bearing member 66 is connected to a ground (not shown) provided in the main body casing 2 for grounding the drum shaft 35 in a state where the process cartridge 20 is mounted on the main body casing 2. Is done.

  The drum shaft 35 supports the drum body 34 so as to be relatively rotatable between the respective bearing members (the left bearing member 66 and the right bearing member (not shown)). A gear member (not shown) is mounted on the left end of the drum body 34 in the axial direction, and the drum body 34 (see FIG. 1) is transmitted to the gear member by transmitting power from a main motor (not shown). It is configured to rotate.

  Further, an upper horizontal portion 64 is disposed above the photosensitive member 29, and a laser for making a laser beam LB (see FIG. 1) scanned at high speed from the scanner portion 19 enter the upper horizontal portion 64. The entrance window 641 (FIG. 1) is opened so as to have a substantially rectangular shape in plan view.

  Further, an upper inclined portion 65 is provided between an inclined portion of the upper end edge of the left upper plate portion 59 and an inclined portion of the upper end edge of the right side wall (not shown), and the upper inclined portion 65 is horizontally horizontal in the front-rear direction. The photosensitive member 29 is disposed obliquely above the rear side with a predetermined distance from the portion 64. The upper inclined portion 65 is provided with the above-described scorotron charger 30 (FIG. 1). The discharge wire 37 (FIG. 1) in the scorotron charger 30 is electrically connected to the electrode 61 shown in FIG. 3, and the grid electrode 38 (FIG. 1) is electrically connected to the electrode 62.

  As shown in FIG. 3, the lower frame 28 is provided with a pair of side walls 92. As shown in FIG. 4, the left side wall 92 has an opening 211 for exposing the transfer electrode 213. Is formed. The left side wall 92 is provided with a cleaning electrode 204 for applying a cleaning bias to the cleaning brush 33 (FIG. 1).

  The developing cartridge 31 is formed in a box shape whose rear side is released, and is detachably attached to the lower frame 28 configured as shown in FIG. 3 as shown in FIG. As shown in FIG. 1, a toner storage chamber 39, a supply roller 40, a development roller 41, and a layer thickness regulating blade 42 are provided in the development cartridge 31. Details of these will be described later.

  The transfer roller 32 is rotatably supported by the lower frame 28. In a state where the upper frame 27 and the lower frame 28 are combined, the transfer roller 32 faces and contacts the photoconductor 29 in the vertical direction. They are arranged to form a nip therebetween. The transfer roller 32 is configured by covering a metal roller shaft 108 with a roller made of a conductive rubber material. A transfer bias is applied to the transfer roller 32 during transfer. The transfer roller 32 is rotationally driven in the opposite direction to the photoconductor 29 by the input of power from a motor (not shown).

  The cleaning brush 33 is attached to the lower frame 28, and is disposed on the rear side of the photoconductor 29 so as to face the photoconductor 29 in a state where the upper frame 27 and the lower frame 28 are combined. ing.

  In the process cartridge 20 configured as described above, the surface of the photosensitive member 29 is first uniformly charged positively by the scorotron charger 30 as the photosensitive member 29 rotates, and then the surface of the photosensitive member 29 from the scanner unit 19 is charged. Exposure is performed by high-speed scanning with a laser beam, and an electrostatic latent image corresponding to an image to be formed on the paper 3 is formed.

  Next, when the toner carried on the developing roller 41 and positively charged is brought into contact with the photosensitive member 29 by the rotation of the developing roller 41, an electrostatic charge formed on the surface of the photosensitive member 29 is formed. The latent image is supplied to the exposed portion of the surface of the photoconductor 29 that is uniformly positively charged and exposed to a laser beam and having a lowered potential. As a result, the electrostatic latent image on the photoconductor 29 is visualized, and a toner image by reversal development is carried on the surface of the photoconductor 29.

  Thereafter, the toner image carried on the surface of the photoconductor 29 is passed through the transfer position between the photoconductor 29 and the transfer roller 32 as shown in FIG. In the meantime, the image is transferred to the paper 3 by a transfer bias applied to the transfer roller 32. The sheet 3 on which the toner image is transferred is conveyed to the fixing device 21.

  Note that the untransferred toner remaining on the photoconductor 29 after the transfer is collected by the developing roller 41. Further, paper dust from the paper 3 adhering to the photoconductor 29 after the transfer is collected by the cleaning brush 33.

  As shown in FIG. 1, the fixing device 21 is provided on the rear side of the process cartridge 20, and includes a fixing frame 48, and a heating roller 49 and a pressure roller 50 in the fixing frame 48.

  The heating roller 49 includes a metal tube whose surface is coated with a fluororesin, and a halogen lamp for heating in the metal tube, and is rotated by input of power from a motor (not shown).

  The pressure roller 50 is disposed below the heating roller 49 so as to press the heating roller 49. The pressure roller 50 is configured by covering a metal roller shaft with a roller made of a rubber material, and is driven in accordance with the rotational drive of the heating roller 49.

  In the fixing device 21, the toner transferred onto the paper 3 at the transfer position is thermally fixed while the paper 3 passes between the heating roller 49 and the pressure roller 50. The sheet 3 on which the toner is fixed is conveyed to a sheet discharge path 51 that extends in the vertical direction toward the upper surface of the main casing 2. The sheet 3 conveyed to the sheet discharge path 51 is discharged onto a sheet discharge tray 53 formed on the upper surface of the main body casing 2 by a sheet discharge roller 52 provided on the upper side.

(2. Configuration of developing cartridge)
Next, the developing cartridge 31 will be described in detail.
As shown in FIG. 1, the developing cartridge 31 is provided with a toner storage chamber 39, a supply roller 40, a developing roller 41, and a layer thickness regulating blade 42.

  The toner storage chamber 39 is formed as an internal space on the front side of the developing cartridge 31 partitioned by the partition plate 43. The toner storage chamber 39 is filled with positively charged non-magnetic one-component toner as a developer. Examples of the toner include polymerizable monomers such as styrene monomers such as styrene, and acrylic monomers such as acrylic acid, alkyl (C1 to C4) acrylate, and alkyl (C1 to C4) methacrylate. Polymerized toner obtained by copolymerization by suspension polymerization or the like is used. Such a polymerized toner has a substantially spherical shape, has extremely good fluidity, and can achieve high-quality image formation.

  Such a toner is blended with a colorant such as carbon black, wax, and the like, and an external additive such as silica is added to improve fluidity. The average particle size of the toner is about 6 to 10 μm.

  An agitator 44 is provided in the toner storage chamber 39. The toner in the toner storage chamber 39 is agitated by the agitator 44 and discharged toward the supply roller 40 from the opening 45 communicating in the front-rear direction below the partition plate 43.

  The supply roller 40 is disposed behind the opening 45 and is rotatably supported by the frame portion 100 of the developing cartridge 31. The supply roller 40 is configured by covering a metal roller shaft with a roller made of a conductive foam material. The supply roller 40 is rotationally driven by power input from a motor (not shown).

  The developing roller 41 is rotatably supported by the frame portion 100 of the developing cartridge 31 in a state where the developing roller 41 is in contact with the supplying roller 40 so as to be compressed with respect to the rear side of the supplying roller 40. Further, the developing roller 41 is opposed to and contacts the photosensitive member 29 in a state where the developing cartridge 31 is mounted on the lower frame 28. The developing roller 41 is configured by covering a metal roller shaft 96 with a roller made of a conductive rubber material. The roller shaft 96 is outward in the width direction (that is, the Z-axis direction (FIG. 7)) at the rear end portion of the developing cartridge 31 with both end portions orthogonal to the front-rear direction (that is, the X-axis direction). (See FIGS. 6 and 7). In the roller of the developing roller 41, the surface of a roller body made of conductive urethane rubber or silicone rubber containing carbon fine particles or the like is coated with a coating layer of urethane rubber or silicone rubber containing fluorine. A developing bias is applied to the developing roller 41 during development. The developing roller 41 is rotationally driven in the same direction as the supply roller 40 by the input of power from a motor (not shown). The drive configuration will be described later.

  The layer thickness regulating blade 42 includes a pressing portion 47 having a semicircular cross section made of insulating silicone rubber at the tip of a blade body 46 made of a metal leaf spring material. The layer thickness regulating blade 42 is supported by the developing cartridge 31 above the developing roller 41, and the pressing portion 47 is pressed onto the developing roller 41 by the elastic force of the blade body 46.

  The toner discharged from the opening 45 is supplied to the developing roller 41 by the rotation of the supply roller 40, and at this time, the toner is positively frictionally charged between the supply roller 40 and the developing roller 41. The toner supplied onto the developing roller 41 enters between the pressing portion 47 of the layer thickness regulating blade 42 and the developing roller 41 as the developing roller 41 rotates, and forms the developing roller 41 as a thin layer having a constant thickness. Supported on. As described above, this toner is supplied to the electrostatic latent image formed on the surface of the photoconductor 29 when it contacts and contacts the photoconductor 29.

  Next, the characteristic structure of the developing cartridge 31 will be described. FIG. 5A is an enlarged view showing an essential part of the developing cartridge, and FIG. 5B is a view showing a state where the supply roller is moved from the state of FIG. 6 is a side view of the developing cartridge, and FIG. 7 is a plan view of the developing cartridge of FIG.

  In the developing cartridge 31 according to the present embodiment, as shown in FIG. 5A, the distance between the outer peripheral surface 40a of the supply roller 40 and the outer peripheral surface 41a of the developing roller 41 is the first distance L1 (see FIG. 5) during image formation. In the example of 5, it is preset so that L1 = 0). That is, the supply roller 40 is configured to contact the developing roller 41 during image formation. On the other hand, during non-image formation, as shown in FIG. 5B, the distance between the outer peripheral surface 40a of the supply roller 40 and the outer peripheral surface 41a of the developing roller 41 is greater than the preset first distance L1. The supply roller 40 can be moved relative to the developing roller 41 so as to be the second distance L2. That is, the supply roller 40 and the developing roller 41 can be arranged with high density during image formation. On the other hand, when the powder toner is collected, the distance between the developing roller 41 and the supply roller 40 is set. It can be enlarged. Therefore, in the state shown in FIG. 5A, the powder toner stays in the region TN shown in the drawing and it becomes difficult to collect the toner. However, if the region TN is opened, as shown in FIG. The powder toner can be satisfactorily collected in a state where it is difficult to clog. In the present embodiment, “when forming an image” refers to when the laser printer 1 performs image formation, and specifically corresponds to when the developing cartridge 31 is mounted. On the other hand, “at the time of non-image formation” refers to the time when the laser printer 1 does not perform image formation, and specifically corresponds to the time when the developing cartridge 31 is detached.

  Focusing on the relationship between the frame portion 100 and the supply roller 40, the frame portion 100 has a facing surface 100a facing the outer peripheral surface 40a of the supply roller 40 as shown in FIG. At the time of formation, the distance between the facing surface 100a of the frame portion 100 and the outer peripheral surface 40a of the supply roller 40 is set in advance so as to be the third distance L3. As shown in FIG. 5B, when the supply roller 40 moves relative to the developing roller 41 during non-image formation, the distance between the facing surface 100a and the outer peripheral surface 40a of the supply roller 40 is The fourth distance L4 is changed to be larger than the preset third distance L3. That is, the supply roller 40 can be separated from both the developing roller 41 and the frame unit 100 by the relative movement of the supply roller 40, and the vicinity of the supply roller 40 is opened wider according to the separation. Therefore, the powder toner is not clogged.

  As shown in FIGS. 6 and 7, in the developing cartridge 31 according to the present embodiment, the frame portion 100 is provided with both side walls 102 and 104 arranged to face each other, and one side wall of the frame portion 100 is provided. A cover member 110 that covers various gears 115, 116, 117, 118, and 122 (see FIG. 8: described later) is attached to 102 by screw members 111, 112, and 113 as fastening members. When 110 is removed, various gears are exposed as shown in FIGS.

  FIG. 8 is a side view of the state in which the cover member 110 is removed as viewed from the side wall 102 side, and FIG. 9 is a perspective view of the state in which the cover member 110 is removed from the back side. FIG. 10 shows a side view seen from the side wall 104 side. 11 is a diagram illustrating a state in which the drive gear and the transmission gear are removed from FIG. 8, and FIG. 12 is a diagram illustrating a state in which the cap member is further removed from FIG.

  As shown in FIGS. 8 and 9, a supply roller gear 122 (the supply roller gear 122 corresponds to the first gear) is attached to the shaft member 120 of the supply roller 40. A detachable drive gear 115 (the drive gear 115 corresponds to the second gear) is disposed to mesh with the roller gear 122 and transmit the driving force to the supply roller gear 122. The drive gear 115 is configured to be driven by receiving a driving force from a motor (not shown). Further, the drive gear 115 is configured to transmit the driving force not only to the supply roller gear 122 but also to the developing roller gear 116 attached to the roller shaft 96 and the transmission gear 117. That is, the drive gear 115 and the gears 116, 122, and 117 are engaged with each other and interlocked with each other. Further, the transmission gear 117 is configured to mesh with the agitator gear 118 interlocked with the shaft member 119 of the agitator 44 and transmit the driving force from the driving gear 117 to the agitator gear 118.

  Also, as shown in FIGS. 8 and 10, the shaft member 120 of the supply roller 40 is provided in a form that penetrates both side walls 102 and 104 of the frame portion 100 and is supported by the side walls 102 and 104, respectively. Yes.

  First, the side wall 102 side will be described. As shown in FIG. 8, the side wall 102 is provided with a groove-shaped guide portion 135 (see also FIG. 12), and at least a part of the guide portion 135 is closed during image formation. A removable cap member 130 is mounted.

  On the other hand, at the time of non-image formation, the drive gear 115 (FIG. 8) and the transmission gear 117 (FIG. 8) are removed as shown in FIG. 11, and the cap is further removed as shown in FIG. When the member 130 (FIG. 11) is removed from the guide part 135, the shaft member 120 can move according to the guide part 135. In this configuration, as shown in FIG. 8, at the time of image formation, a part of the guide portion 135 is closed by the cap member 130 to prevent leakage of powder toner from the guide portion 135, and at the time of non-image formation, FIG. As described above, the shaft member 120 can be moved according to the guide portion 135 by removing the cap member 130.

  FIG. 13 shows a perspective view and a plan view of the cap member, and the cap member 130 is formed in a plate shape as shown in FIGS. 13 (a) and 13 (b). An abutting portion 130a that is concave so as to have an arc shape in plan view is formed at the end on the opposite side. The contact portion 130a functions as a part of a bearing that supports the shaft member 130. Moreover, the edge part on the opposite side to the contact part 130a is comprised by the planar view circular arc shape. The cap member 130 is accommodated in a groove-shaped accommodation portion 102b formed on the side wall 102, and supported by a support surface 102a described later.

  FIG. 14 shows a cross-sectional view of a state in which the cap member 130 is mounted on the guide portion 135. As shown in FIG. 14, the guide portion 135 has the above-described support surface 102a that supports the outer surface of the cap member 130. The cap member 130 includes a guide portion in a state where a sheet-like double-sided tape 133 (the double-sided tape 133 corresponds to an adhesive medium) is interposed between the support surface 102a and the outer surface of the cap member 130. 135 is attached. In this configuration, separation of the cap member 130 can be effectively prevented by the adhesive force of the double-sided tape 133, and the gap between the outer surface of the cap member 130 and the support surface 102a can be filled by the interposition of the double-sided tape 133.

  As described above, in this embodiment, the shaft member 120 of the supply roller 40 passes through the frame portion 100, and the tip portion 120a of the shaft member 120 relatively moves the supply roller 40 as shown in FIG. The distal end portion 120a of the shaft member 120 moves along the guide portion 135 as shown in an enlarged view in FIG.

  Further, as described above, the supply roller gear 122 is attached to the shaft member 120 of the supply roller 40, and the drive gear 115 that transmits the drive force to the supply roller gear 122 is disposed on the frame portion 100. In the embodiment, as illustrated in FIG. 12, the operation unit can be operated by removing the drive gear 115. That is, the drive force can be reliably transmitted from the drive gear 115 to the supply roller gear 122 attached to the shaft member 120 during image formation, and the supply roller gear 122 and the drive gear 115 are disengaged and supplied during non-image formation. The roller 40 can be moved favorably.

  In the example of FIGS. 12 and 15A, both the drive gear 122 and the supply roller gear 122 are configured to be removed, and the “operation unit” is the shaft member after the supply roller gear 122 is removed. As shown in FIG. 15B, only the drive gear 122 of the drive gear 122 and the supply roller gear 122 is removed, and the supply roller gear 122 itself is used as an operation unit. Also good. That is, it may be configured such that it can be moved by operating the supply roller gear 122 while the supply roller gear 122 is mounted.

  In this embodiment, as shown in FIG. 2, after the developing cartridge 31 is detached from the apparatus main body 1a, the supply roller 40 can be relatively moved as shown in FIGS. ing. That is, the operator can perform the relative movement operation of the supply roller 40 in a wide space outside the apparatus main body, and the worker can easily collect the powder toner. .

  In the present embodiment, the guide portion 155 is also provided on the side wall 104 on the opposite side of the side wall 102 in the frame portion 100. As shown in FIG. 10, the side wall 104 supports one end side of the shaft member 120, but a groove-shaped guide portion 155 similar to the guide portion 135 is formed on the side wall 104 so as to guide the shaft member 120. Is also provided. The guide portion 155 is closed by a cap member 150 similar to the cap member 130 during image formation, and the shaft member 120 is movable along the guide portion 155 by removing the cap member 150 during non-image formation. The In this embodiment, as shown in FIG. 10, the cover member 140 is attached to the side wall 104 by a screw member 119, and the cap member 150 is normally closed by the cover member 140. On the other hand, at the time of non-image formation, the cap member 150 is exposed and can be removed by removing the cover member 140, and the guide member 155 is exposed and the shaft member 120 is removed by removing the cap member 150. It will be movable.

<Other embodiments>
The present invention is not limited to the embodiments described with reference to the above description and drawings. For example, the following embodiments are also included in the technical scope of the present invention, and further, within the scope not departing from the gist of the invention other than the following. Various modifications can be made.

(1) In the above-described embodiment, the developing roller and the supply roller are in contact with each other at the time of image formation, and the development roller and the supply roller are separated at the time of non-image formation. For example, when the image is formed, the distance between the developing roller and the supply roller is kept at a first distance that does not come into contact, and the non-image formation causes the supply roller to develop so that the second distance is larger than the first distance. It may be possible to move relative to the roller.
(2) In the above embodiment, as an example at the time of non-image formation, the developing cartridge 31 is shown detached from the apparatus main body 1a. However, if no image formation is performed, the developing cartridge is attached to the apparatus main body. In this state, the supply roller is relatively movable (that is, the outer peripheral surface of the supply roller is relatively movable with respect to at least one of the outer peripheral surface of the developing roller and the opposite surface of the frame portion (preferably both)). May be.

1 is a side sectional view of a main part showing an embodiment of a laser printer as an image forming apparatus of the present invention, showing a state in which a front cover is closed; FIG. 2 is a side cross-sectional view of the main part of the laser printer shown in FIG. 1 and shows a state in which a front cover is opened. The side view which shows the state which removed the developing cartridge regarding the process cartridge used for the laser printer of FIG. Side view of a process cartridge used in the laser printer of FIG. (A) is an enlarged view showing an essential part of the developing cartridge, and (b) is a view showing a state where the supply roller is moved from the state (a). Side view of a developing cartridge used in the laser printer of FIG. FIG. 5 is a plan view of the developing cartridge of FIG. The figure which shows the state which removed the side cover regarding the developing cartridge of FIG. The perspective view which looked at the developing cartridge of the state of FIG. 8 from the back side Side view of the developer cartridge as viewed from the side opposite the drive gear side The figure which shows the state which removed the drive gear and the transmission gear from FIG. The figure which shows the state which removed the cap member from FIG. Explanatory drawing explaining a cap member Explanatory drawing which shows the relationship between a cap member and a frame part (A) Explanatory drawing explaining the state which moves a shaft member along a guide part, (b) is explanatory drawing explaining the aspect different from (a).

1. Laser printer (image forming device)
1a ... main body 3 ... paper (recording medium)
20 ... Process cartridge 21 ... Fixing device 29 ... Photoconductor (image carrier)
31. Developing cartridge (developing device)
DESCRIPTION OF SYMBOLS 40 ... Supply roller 40a ... Outer peripheral surface of supply roller 41 ... Developing roller 41a ... Outer peripheral surface of developing roller 100 ... Frame portion 100a ... Opposing surface 102 ... Side wall 102a ... Support surface 104 ... Side wall 115 ... Drive gear (second gear)
120... Shaft member 120a...
122 ... Supply roller gear (first gear)
130: Cap member 133: Double-sided tape (sticking medium)
135: Guide portion L1: First distance L2: Second distance L3: Third distance L4: Fourth distance TN: Powder toner

Claims (16)

A developing device that is detachably provided in the apparatus main body of the image forming apparatus and that develops the electrostatic latent image with a powder toner to make it visible.
A developing roller facing the image carrier;
A supply roller for supplying the powder toner to the developing roller;
A frame portion that contains the powder toner and rotatably supports the developing roller and the supply roller;
With
At the time of image formation, the distance between the outer peripheral surface of the supply roller and the outer peripheral surface of the developing roller is a preset first distance at a position where the supply roller and the developing roller face each other. The roller is immovable relative to the developing roller;
During the non-image forming, before Kiko plants, the distance between the outer peripheral surface of the developing roller and the outer peripheral surface of the feed roller, from the first distance, the greater second distance greater than said first distance Thus, the developing device is characterized in that the supply roller is movable relative to the developing roller. The frame portion has a facing surface disposed facing the outer peripheral surface of the supply roller,
As the supply roller moves relative to the developing roller, a distance between the facing surface of the frame portion and the outer peripheral surface of the supply roller is set to a third distance from a preset third distance. The developing device according to claim 1, wherein the developing device is changed so as to be a fourth distance larger than the first distance. A developing device that is detachably provided in the apparatus main body of the image forming apparatus and that develops the electrostatic latent image with a powder toner to make it visible.
A developing roller facing the image carrier;
A supply roller for supplying the powder toner to the developing roller;
A frame portion that contains the powder toner and rotatably supports the developing roller and the supply roller;
With
The frame portion has a facing surface disposed facing the outer peripheral surface of the supply roller,
At the time of image formation, the distance between the facing surface of the frame portion and the outer peripheral surface of the supply roller is a third distance set in advance, and the supply roller cannot move relative to the facing surface. And
During the non-image forming, so that the distance between the outer peripheral surface of the supply roller and the opposing surface of the frame part, from the third distance, the said third fourth distance greater than the distance, the supply A developing device, wherein a roller is movable relative to the facing surface. 4. The developing device according to claim 1 , wherein the supply roller is relatively movable after the developing device is detached from the apparatus main body. 5. The shaft member of the supply roller passes through the frame portion,
Tip of the shaft member, a developing device according to any one of claims 1 to 4, characterized in that it is an operation section for relatively moving the supply roller. A first gear is attached to the shaft member of the supply roller,
A detachable second gear for meshing with the first gear and transmitting a driving force to the first gear is disposed on the frame portion,
The developing device according to claim 5 , wherein, when the non-image is formed, the operation unit can be operated by releasing the meshing between the first gear and the second gear. Wherein during non-image formation, by removing only the second gear of said first gear and said second gear, according to claim 6, wherein the operating portion is operable Development device. The developing device according to claim 6 , wherein the operation unit is operable by removing both the first gear and the second gear during the non-image formation. The frame unit, a developing device according to any one of claims 5 to 8 characterized in that it has a guide portion for guiding the shaft member of said supply roller. The frame portion has both side walls disposed opposite to each other in the axial direction of the supply roller,
The shaft member of the supply roller is provided so as to penetrate each side wall and be supported by each side wall,
The guide portion includes a developing device according to claim 9, characterized in that provided respectively on the two side walls of said frame portion. The guide portion is formed in a groove shape,
At the time of image formation, a detachable cap member that closes at least a part of the guide portion is provided,
During the non-image forming, by which the cap member is detached from said guide unit, a developing device according to claim 9 or claim 10 wherein the shaft member is characterized by comprising a movable according to said guide portion. The guide portion is provided with a support surface that supports the outer surface of the cap member,
The developing device according to claim 11 , wherein the cap member is attached to the guide portion in a state where a sheet-like sticking medium is interposed between the support surface and the outer surface of the cap. The supply roller, a developing apparatus according to any one of claims 1 to 12, characterized in that forming the structure of the developing roller and the contact at the time of image formation. An image forming apparatus comprising the developing device according to any one of claims 1 to 13. An image carrier;
A developing roller facing the image carrier;
A supply roller for supplying the powder toner to the developing roller;
A frame portion that contains the powder toner and rotatably supports the developing roller and the supply roller;
With
At the time of image formation, the distance between the outer peripheral surface of the supply roller and the outer peripheral surface of the developing roller is a preset first distance at a position where the supply roller and the developing roller face each other. The roller is immovable relative to the developing roller;
During the non-image forming, before the Kiko plants, the distance between the outer peripheral surface of the outer peripheral surface of the supply roller and the developing roller, so that the first the distance from the first large second distance greater than the distance In addition, the supply roller is movable relative to the developing roller. An image carrier;
A developing roller facing the image carrier;
A supply roller for supplying the powder toner to the developing roller;
A frame portion that contains the powder toner and rotatably supports the developing roller and the supply roller;
With
The frame portion has a facing surface disposed facing the outer peripheral surface of the supply roller,
At the time of image formation, the distance between the facing surface of the frame portion and the outer peripheral surface of the supply roller is a third distance set in advance, and the supply roller cannot move relative to the facing surface. And
During the non-image forming, so that the distance between the outer peripheral surface of the supply roller and the opposing surface of the frame portion becomes larger fourth distance than the third distance from the third distance, the feed roller However, the image forming apparatus can be moved relative to the facing surface.

Images