JP2004085593A - Device and method for transmitting driving to developer carrier, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably and accurately rotate a developer carrier not only initially but also after the lapse of time in a device for transmitting driving to the developer carrier in an image forming apparatus. <P>SOLUTION: A rotary developing device 14 is provided with four developing units 22. Each developing unit is equipped with a developing roller (developer carrier) 25, and a magnet attaching part 52a is formed on the shaft 52 of the roller 25, and a magnet 53 is fixed by adhesion on the end face of the magnet attaching part of the developing unit existing at a developing position. The magnet constitutes a magnetic coupling 55 with a pair of magnets 54 opposed through a void (s). A pair of magnets 54 is fixed on the rotary shaft 57 of a driving unit 56 properly supported in a copying machine device main body 10. Thus, rotational force from the driving unit being a driving source is transmitted to the roller 25 through the magnetic coupling 55. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention can be applied to, for example, an image forming apparatus such as a copier, a printer, a facsimile, or a multifunction peripheral thereof. In particular, the electrostatic latent image is formed on the image carrier by writing after charging, and then the electrostatic latent image is visualized by attaching toner with a developing device to form an image on the image carrier. The present invention relates to an electrophotographic image forming apparatus that forms an image, transfers the image, and records the image on a transfer material such as a sheet of paper, an OHP film, and an intermediate transfer member. Further, in a developing device used in such an electrophotographic image forming apparatus, a developing device rotates and transports a developer, adheres the developer to an image carrier, and develops a latent image on the image carrier. More specifically, the present invention relates to a drive transmission device and a drive transmission method for the developer carrier.
[0002]
[Prior art]
Conventionally, in an image forming apparatus, a rotational force from a driving source is transmitted to a developer carrying member provided in a developing device by using a drive transmitting device as shown in FIG.
[0003]
In the figure, reference numeral 1 denotes a developing roller serving as a developer carrier, and a developing roller gear 3 is fixed to a roller shaft 2 of the developing roller. The developing device was also provided with two screws as stirring members for stirring the developer, and the screw gears 4 were also fixed to those screws. One intermediate gear 5 meshes with the developing roller gear 3 and the two screw gears 4, and an external drive gear 6 meshes with the intermediate gear 5.
[0004]
As a result, a rotational force from a drive source (not shown) such as a motor is transmitted to the drive gear 6, and the developing roller gear 3 and the two screw gears 4 are rotated via the intermediate gear 5. The developer is rotated to stir the developer, and the developing device attaches the developer to the developing roller 1, rotates the developing roller 1 to convey the developer, attaches the developer to the image carrier, and transfers the developer to the image carrier. The upper latent image was being developed.
[0005]
By the way, in order to eliminate density unevenness (streaked unevenness having different densities in the case of a single color) and hue unevenness (unevenness having different streaks in a multicolored manner) due to banding or the like, the development of the developing roller 1 and the like is performed. It is important to rotate the agent carrier accurately. In the conventional image forming apparatus, as described above, the drive transmission to the developer carrier is usually performed using a gear. For this reason, it is necessary to increase the number of gears leading to the developer carrier and the accuracy of each gear. In recent years, as the molding technology has improved, the rotational accuracy of the developer carrier has been improved by changing from a spur gear to a helical gear.
[0006]
It is also known that unevenness occurs every rotation due to the relative rotational position accuracy between the developer carrier such as the developing roller 1 and the developing roller gear 3. Therefore, the developing roller gear 3 is mounted on the roller shaft 2 by increasing the D-cut accuracy as shown in FIG. 14A or by improving the engagement accuracy of the pin 7 as shown in FIG. The accuracy was improved.
[0007]
[Problems to be solved by the invention]
However, in this type of image forming apparatus, even if a good image can be obtained at the initial stage, the gear wears out over a long period of use, and the developer carrier such as the developing roller 1 is not accurately positioned. There is a problem that the image cannot be rotated well, and density unevenness and hue unevenness due to banding or the like occur to deteriorate image quality.
[0008]
Therefore, a first object of the present invention is to provide a drive transmission device for a developer carrier in an image forming apparatus as described above, which stably and accurately rotates the developer carrier both initially and with time. Is to be able to do that.
[0009]
A second object of the present invention is to eliminate wear as much as possible by eliminating contact and to facilitate application to a rotary developing device.
[0010]
A third object of the present invention is to stably and reliably rotate a developer carrying member using a motor.
[0011]
A fourth object of the present invention is to provide an image forming apparatus including a drive transmission device that achieves the above object.
[0012]
A fifth object of the present invention is to eliminate the need for a motor or the like, to eliminate the vibration of the motor shaft or the like, to eliminate the occurrence of hue unevenness, and to prevent the image quality from deteriorating.
[0013]
[Means for Solving the Problems]
Therefore, the invention described in claim 1 aims at achieving the first object.
In a drive transmission device to a developing carrier in an image forming apparatus that rotates the developer carrier to convey the developer, adheres the developer to the image carrier, and develops a latent image on the image carrier,
It is characterized in that a rotational force from a drive source is transmitted to a developer carrier via a magnetic coupling.
[0014]
According to a second aspect of the present invention, in order to achieve the second object, in the drive transmitting device to the developing carrier according to the first aspect, a gap is provided between a pair of magnets constituting a magnetic coupling. It is characterized by.
[0015]
According to a third aspect of the present invention, in order to achieve the third object, in the drive transmission device for the development carrier according to the first aspect, a motor is used as a drive source.
[0016]
According to a fourth aspect of the present invention, in order to achieve the fourth object, an image forming apparatus is provided with the drive transmission device to the developing carrier according to any one of the first to third aspects. I do.
[0017]
The invention described in claim 5 is to achieve the first object.
A method of transmitting a developer by rotating a developer carrier, transferring the developer, and attaching the developer to the image carrier to develop a latent image on the image carrier, a drive transmission method to the development carrier in an image forming apparatus,
It is characterized in that a rotational force from a drive source is transmitted to a developer carrier via a magnetic coupling.
[0018]
The invention according to claim 6 is to achieve the fifth object,
In a drive transmission device to a developing carrier in an image forming apparatus that rotates the developer carrier to convey the developer, adheres the developer to the image carrier, and develops a latent image on the image carrier,
A fixed output member provided with a plurality of electromagnets sequentially turned on and off by a driving device in a circumferential direction, and a rotary input member which rotates under the magnetic action of the fixed output member by the electromagnet to rotate the developer carrier. It is characterized by.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a color copying machine provided with a drive transmitting device to a developer carrier according to the present invention, and shows an overall schematic configuration in a copying machine main body.
[0020]
In the main body of the copying machine indicated by reference numeral 10 in the figure, an image carrier 12 in the form of a drum is provided at the upper center in the outer case 11 slightly to the right and forward and backward. Around the image carrier 12, a rotary developing device 14, an intermediate transfer device 15, a pre-cleaning neutralization device 16 a and a cleaning device are arranged in order from a charging device 13 provided on the image carrier 12 in a rotation direction (counterclockwise direction) indicated by an arrow in FIG. 16, a pre-charging static eliminator 13a is provided. A laser writing device 18 is provided on the charging device 13, the developing device 14, the cleaning device 16, and the pre-charging static eliminator 13a.
[0021]
As shown in FIG. 2, the rotary developing device 14 includes developing units 22A, 22B, and 22C that store yellow, magenta, cyan, and black toners between unit side plates 21 before and after being connected by a developing support 20. In addition to supporting the toner cartridges 22D, the toner cartridges 23A, 23B, 23C, and 23D that store the toners of the same color corresponding thereto are supported.
[0022]
The developing devices 22A, 22B, 22C, and 22D of the respective colors contain a developing roller (developer carrier) 25, a first conveying screw 26, a second conveying screw 27, and a developing doctor 28 in a developing case 24, respectively. . Then, the toner is transported from the second transport screw 27 to the first transport screw 26, from the first transport screw 26 to the developing roller 25, and the toner adhered to the developing roller 25 is thinned by the developing doctor 28.
[0023]
The toner cartridges 23A, 23B, 23C, and 23D of the respective colors are detachably attached to the cartridge guide 29, respectively. The cartridge guide 29 is provided with a toner supply screw 30. Then, the toner in each toner cartridge is individually supplied into the corresponding developing case 24 by the toner supply screw 30.
[0024]
The developing device 14 configured as described above is rotated around a central axis 31 provided at the center of the developing support 20 to selectively and appropriately select the developing rollers 25 of the developing devices 22A, 22B, 22C, and 22D of the respective colors. The outer periphery of the carrier 12 can be opposed.
[0025]
Next, as shown in FIG. 1, the intermediate transfer device 15 wraps an endless belt-shaped intermediate transfer member 34 over a plurality of rollers 33, and a part of the intermediate transfer member 34 contacts the image carrier 12. A transfer device 35, a belt cleaning device 36, and a belt neutralization device 37 are provided on the outer periphery of the intermediate transfer body 34. The belt cleaning device 36 can freely contact and separate from the intermediate transfer body 34 as appropriate.
[0026]
As is well known, the laser writer 18 irradiates a laser beam L in accordance with the content read by the optical reader 38 to perform writing, and forms an electrostatic latent image on the image carrier 12. The optical reader 38 reads the contents of a document set on a contact glass 39 provided on the upper surface of the apparatus main body 10.
[0027]
Reference numeral 40 in FIG. 1 denotes a transfer material transport path that transports a transfer material such as paper from right to left in the figure. The transfer material transport path 40 includes a plurality of pairs of transport rollers 41 and a pair of registration rollers 42 in front of the opposed intermediate transfer device 15 and the transfer device 35, and a transport belt 43, a fixing device 44, and a discharge roller pair 45. Is provided.
[0028]
Although not shown, the apparatus main body 10 is placed on, for example, a sheet feeding device. Then, the transfer material sent from the paper feeding device is guided to the transfer material transporting path 40 through the automatic paper feeding path 47 in the apparatus main body 10. In addition, a manual feed tray 48 is provided on the right side surface of the apparatus main body 10 so as to be freely opened and closed. Then, the transfer material guided and inserted by the opened manual feed tray 48 is guided to the transfer material transport path 40 through the manual feed path 49 in the apparatus main body 10. Conversely, a paper discharge tray 50 is detachably attached to the left side surface of the apparatus main body 10. Then, the transfer material discharged by the discharge roller pair 45 through the transfer material conveyance path 40 is received by the discharge tray 50.
[0029]
When making a color copy using this color copier, a document is set on the contact glass 39 and a start switch (not shown) is pressed as usual. Then, the transfer material sent from the paper feeding device is guided to the transfer material transport path 40 through the automatic paper feed path 47 or the transfer material set on the manual feed tray 48 is transferred to the transfer material transport path 40 through the manual feed path 49. It is conveyed by the conveying roller pair 41 and is brought into contact with the registration roller pair 42 to be stopped.
[0030]
At the same time, the optical reader 38 is operated to scan along the original surface, and read the contents of the original set on the contact glass 39. Further, the image carrier 12 is rotated counterclockwise in the figure, and the intermediate transfer body 34 is conveyed clockwise by the rotation of the plurality of rollers 33. Then, as the image carrier 12 rotates, the surface thereof is first uniformly charged by the charging device 13, and then the laser beam L is irradiated by the laser writing device 18 in accordance with the content read by the optical reading device 38. The first color electrostatic latent image is formed on the image carrier 12 by writing the color.
[0031]
Then, with the rotation of the image carrier 12, toner is adhered by the developing device 22A for the first color of the developing device 14 to visualize the electrostatic latent image, and the first color image is formed to form the monochromatic image. The image is transferred onto the intermediate transfer body 34 of the intermediate transfer device 15. After the transfer, the surface of the image carrier 12 is neutralized by a pre-cleaning neutralization device 16a in order to enhance the cleaning effect, and then the residual toner of the first color is removed by the cleaning device 16 and neutralized by a pre-charge neutralization device 13a.
[0032]
Thereafter, similarly, with the rotation of the image carrier 12, the image is uniformly charged, the second color is written, and the developing device 14 is rotated to use the second color developing device 22 </ b> B facing the image carrier 12. Then, the second-color single-color image formed on the image carrier 12 is transferred onto the intermediate transfer member 34 so as to be superimposed on the first-color single-color image. Similarly, the surface of the image carrier 12 after the transfer is removed, cleaned, and removed again.
[0033]
Similarly, a third-color single-color image is formed on the image carrier 12 and transferred onto the intermediate transfer member 34, and if necessary, a black image is also formed on the image carrier 12 to form an intermediate transfer member. The resultant image is transferred onto the intermediate transfer member 34 and eventually forms a composite color image on the intermediate transfer member 34 in accordance with the contents of the document.
[0034]
Thereafter, the registration roller pair 42 is rotated in synchronization with the conveyance of the intermediate transfer body 34, and the above-described transfer material that has been abutted against the registration roller pair 42 is fed between the intermediate transfer device 15 and the transfer device 35. Then, the transfer device 35 transfers the color image on the intermediate transfer body 34 onto the transfer material. Thereafter, the transfer material after the color image transfer is conveyed by the conveyance belt 43 and put into the fixing device 44, and heat and pressure are applied between the rollers to fix the transferred image. After fixing, the sheet is discharged by a sheet discharge roller 45 and sequentially stacked on a sheet discharge tray 50.
[0035]
On the other hand, the surface of the intermediate transfer member 34 after the transfer of the color image is removed at a proper timing by a belt cleaning device 36 pressed against the intermediate transfer member 34 to remove the residual toner, and is discharged by a discharging device 37.
[0036]
As shown in FIG. 3, a roller shaft (driven shaft) 52 of each developing roller 25 protrudes through one of the unit side plates 21 to form a magnet mounting portion 52a at the tip and a magnet 53 on the end surface. Fix by adhesion or the like. As shown in FIG. 4, the magnet 53 is provided with four magnetic poles alternately arranged in the circumferential direction. The magnet 53 is opposed to a pair of magnets 54 provided with four magnetic poles alternately NS in the circumferential direction with a gap s.
[0037]
The magnetic coupling 55 is constituted by the pair of magnets 53 and 54 by attracting each other with different magnetic poles. The pair of magnets 54 are fixed to a rotation shaft (drive shaft) 57 of a drive unit 56 as a drive source. The drive unit 56 is appropriately fixed and supported in the copying machine main body 10.
[0038]
As a result, the rotating shaft 57 and the roller shaft 52 are magnetically connected via the magnetic coupling 55 with a gap s therebetween, and when the driving unit 56 rotates the rotating shaft 57, the rotational force is transmitted to the magnetic coupling 55. The developer is transported by rotating the developing roller 25, and the developer is attached to the image carrier 12 to develop a latent image on the image carrier 12.
[0039]
In the illustrated example, since the four magnetic poles attract each other, the rotating shaft 57 and the roller shaft 52 can be firmly connected by the magnetic coupling 55. The magnetic poles may be formed by magnetizing the magnets 53 and 54 or may be formed by embedding the magnets.
[0040]
Thereafter, when the developing device 14 is rotated around the central axis 31 and the next developing device 22 faces the outer periphery of the image carrier 12, the magnet 53 of the developing roller 25 provided in the next developing device 22 becomes a fixed magnet. A new magnetic coupling 55 is formed by forming a pair facing the first magnetic coupling 55. Then, the rotational force of the drive unit 56 is transmitted to rotate the developing roller 25, and the latent image on the image carrier 12 is developed using the next developing unit 22.
[0041]
Subsequently, when the developing device 14 is rotated about the central axis 31 and the next developing device 22 faces the outer periphery of the image carrier 12, the magnet 53 of the developing roller 25 provided in the next developing device 22 A pair is formed facing the fixed magnet 54, and a new magnetic coupling 55 is formed. Then, the rotational force of the drive unit 56 is transmitted to rotate the developing roller 25, and further, the latent image on the image carrier 12 is developed using the next developing unit 22.
[0042]
With the above configuration, the rotational force from the driving source is transmitted to the developing roller 25 via the magnetic coupling 55, so that the drive transmitting device to the developing roller 25 in the image forming apparatus eliminates wear, and The developing roller 25 can be stably and accurately rotated over time.
[0043]
Further, according to the illustrated example, since a gap is provided between the pair of magnets 53 and 54 constituting the magnetic coupling 55, the contact can be eliminated as much as possible and the wear can be reduced. In addition, when the developing device 14 is rotated by applying one of a pair of magnets to the rotating developing device side and fixing the other to the driving source side by applying to an image forming apparatus including the rotary developing device 14, By preventing the next magnet 53 on the developer carrier from colliding with the fixed magnet 54 on the drive source side, application to the rotary developing device 14 can be facilitated.
[0044]
Next, a case where the present invention is applied to a tandem image forming apparatus will be described.
FIG. 5 shows the overall schematic configuration of a tandem-type printer.
[0045]
Reference numeral 60 in the figure denotes a printer device main body. A transfer material transport belt 62 is provided in the pudding body main body 60 so as to be rotatable in a counterclockwise direction by being stretched between two rollers 61. In the transfer material transport belt 62, four transfer devices 63 are provided at regular intervals. On the transfer material transport belt 62, four image forming means 64A, 64B, 64C, and 64D of yellow, magenta, cyan, and black are sequentially arranged from the upstream side to the downstream side.
[0046]
Each image forming means 64 includes a drum-shaped image carrier 65 opposed to the transfer device 63 with the transfer material conveying belt 62 interposed therebetween. A charging device 66, a writing device 67, a developing device 68, and a cleaning device 69 are provided around each image carrier 65, respectively.
[0047]
A transfer material transfer path is formed between the transfer material transfer belt 62 and the four image forming means 64A, 64B, 64C, and 64D. A registration roller 70 is provided upstream of the transfer material transfer path, and a fixing device 71 is provided downstream.
[0048]
On the other hand, below the transfer material transport belt 62, a plurality of paper feed cassettes 72 are provided. Each paper feed cassette 72 is provided with a paper feed unit 73, and a paper feed path 74 is formed from the paper feed unit 73 to the registration roller 70.
[0049]
Then, at the time of image formation, each image forming means 64 forms an image for each color of yellow, magenta, cyan, and black based on a signal from the host. On the other hand, the transfer material is fed out of the paper supply cassette 72 by the paper supply unit 73, conveyed through the paper supply path 74, and the leading end thereof is abutted against the registration roller 70.
[0050]
Then, the transfer material is sent out by rotating the registration roller 70 in synchronization with the rotation of the image carrier 65, the images on the image carrier 65 are sequentially transferred to the transfer material by the transfer device 63, and the image is transferred through the fixing device 71. After the transferred image is fixed, the image is discharged onto a stack tray (not shown) externally attached to the printer apparatus main body 60.
[0051]
Now, also in such a tandem image forming apparatus, a developing roller (developer carrier) 76 is provided in the developing device 68 of each image forming means 64, and the developing roller 76 is rotated to convey the developer. A developer is attached to each image carrier 65 to develop a latent image on each image carrier 65.
[0052]
As shown in FIG. 6, both ends of the roller shaft (driven shaft) 77 of each developing roller 76 are supported by side plates (not shown) of the developing device 68 via bearings 78. Then, a magnet 80 that is NS-magnetized in the axial direction is fixed to the tip protruding through the side plate. The magnet 80 magnetically attracts and closely adheres a pair of magnets 81 which are similarly NS-magnetized in the axial direction. Then, a magnetic coupling 82 is constituted by the pair of magnets 80 and 81.
[0053]
The pair of magnets 81 is fixed to a rotation shaft (drive shaft) 83 to which a rotation force from a motor (drive source) not shown is transmitted. The motor and the rotating shaft 83 are appropriately supported inside the printer device main body 60.
[0054]
Then, the rotating shaft 83 and the roller shaft 77 are magnetically connected via a magnetic coupling 82, and when the rotating shaft 83 is rotated by a motor (not shown), the rotational force is transmitted via the magnetic coupling 82, The developer is conveyed by rotating the developing roller 76 of each developing device 68, and the developer adheres to the image carrier 65 to develop a latent image on each image carrier 65.
[0055]
In the above-described example, the magnets 80 and 81 are magnetized in the axial direction. However, as shown in FIG. 7, the magnets 80 and 81 are magnetized in a direction perpendicular to the axial direction, and their north poles are attracted to the south pole of the other party. The rotational force from the drive source may be transmitted to the developing roller 76 via the magnetic coupling 82.
[0056]
With the above configuration, the rotational force transmitted from the motor 84 via the rotating shaft 83 is transmitted to the developing roller 76 via the magnetic coupling 82, so that the drive transmitting device to the developing roller 76 in the image forming apparatus Thus, the developing roller 25 can be stably and accurately rotated both at an initial stage and over time.
[0057]
By the way, also in the tandem printer shown in the drawing, the developing device 68 is provided with two screws as stirring members for stirring the developer, and the screw gears 85 are fixed to these screws as shown in FIG. A drive gear 86 is meshed with the screw gears 85 as shown in FIG. The drive gear 86 is appropriately supported inside the printer apparatus main body 60, and is fixed to a rotating shaft 87 that rotates by transmitting a rotational force from another motor (not shown).
[0058]
In the above-described drive transmission device for the developer carrier, the rotational force from a drive source such as a motor is transmitted to the developer carrier via a magnetic coupling. However, as shown in FIG. 10A, for example, a disk-shaped rotation input member 91 is fixed on a roller shaft 90 of a developing roller (developer carrier), and is opposed to the rotation input member 91 on the image forming apparatus main body side. The fixed output member 92 shown in B) may be fixedly provided.
[0059]
In the illustrated example, the rotation output member 91 is magnetized to the S pole at a symmetrical position with respect to the roller shaft 90. On the other hand, the fixed output member 92 includes a plurality of electromagnets 93 arranged in the circumferential direction. The fixed output member 92 is provided by being attached to an aluminum die-cast 94, for example, as shown in FIG. The electromagnet 93 is configured by winding a coil 96 around an iron core 95 as shown in FIG.
[0060]
Then, a plurality of electromagnets 93 of the fixed output member 92 are sequentially turned on and off in the circumferential direction by flowing and stopping a current to the coil 96 by a driving device (not shown), and the rotation input member is subjected to the magnetic action of the electromagnets 93. Rotate 91. That is, by sequentially turning on and off the electromagnet 93, N poles are sequentially generated in the circumferential direction, the S pole of the rotation output member 91 is sequentially attracted, and the rotation output member 91 is rotated about the roller shaft 90 by the fixed output member 92.
[0061]
As a result, the developing roller rotates together with the roller shaft 90 to convey the developer, adheres the developer to the image carrier, and develops the latent image on the image carrier.
[0062]
For example, in a conventional example shown in FIG. 12, a drive gear 102 for rotating a developer carrier (not shown) is fixed to the tip of a motor shaft 101 of the motor 100, so that the motor 100 is driven to rotate the developer carrier. At this time, there is a problem in that the motor shaft 101 shakes to generate hue unevenness or the like, thereby deteriorating image quality. However, with the configuration as shown in FIG. 10, the motor 100 and the like are not required, the vibration of the motor shaft 101 and the like is eliminated, and the occurrence of hue unevenness and the like can be eliminated, thereby preventing the image quality from deteriorating.
[0063]
【The invention's effect】
As described above, according to the first aspect of the present invention, the rotational force from the drive source is transmitted to the developer carrier via the magnetic coupling, so that the drive is transmitted to the developer carrier in the image forming apparatus. In the apparatus, wear can be eliminated, and the developer carrier can be stably and accurately rotated at an initial stage and over time to eliminate development unevenness.
[0064]
According to the second aspect of the present invention, since a gap is provided between the pair of magnets constituting the magnetic coupling, contact can be eliminated as much as possible and wear can be eliminated. Also, when the developing device is rotated by applying one of a pair of magnets to the rotating developing device and fixing the other to the drive source side by applying to an image forming apparatus having a rotary developing device, By preventing the magnet on the developer carrier side from colliding with the fixed magnet on the drive source side, application to a rotary developing device can be facilitated.
[0065]
According to the third aspect of the present invention, since the motor is used as the drive source, the developer carrier can be stably and reliably rotated using the motor.
[0066]
According to the fourth aspect of the present invention, the image forming apparatus includes the drive transmission device having the above-described effect, because the drive transmission device for the development carrier is provided. be able to.
[0067]
According to the fifth aspect of the present invention, the rotational force from the drive source is transmitted to the developer carrier via the magnetic coupling. As in the invention according to the first aspect, wear can be eliminated, and the developer carrier can be stably and accurately rotated both initially and with time.
[0068]
According to the invention described in claim 6, the fixed output member includes a plurality of electromagnets sequentially turned on and off by the driving device and is arranged in the circumferential direction, and the fixed output member is rotated by the magnetic action of the electromagnets to carry the developer. Since the rotation input member for rotating the body is provided, a motor or the like is not required, the vibration of the motor shaft or the like is eliminated, the occurrence of hue unevenness or the like is prevented, and the deterioration of image quality can be prevented.
[Brief description of the drawings]
FIG. 1 is a color copier including a drive transmitting device to a developer carrier according to the present invention, and is an overall schematic configuration diagram of a main body of the copier device.
FIG. 2 is an overall schematic configuration diagram of the rotary developing device.
FIG. 3 is a perspective view showing a drive transmission device to a developer carrier provided in the rotary developing device.
FIG. 4 is a perspective view showing a magnetic coupling of the drive transmission device.
FIG. 5 is an overall schematic configuration diagram of a tandem-type printer including a drive transmission device to a developer carrier according to the present invention.
FIG. 6 is an explanatory view showing a drive transmission device to the developer carrier.
FIG. 7 is a perspective view showing another example of the drive transmission device to the developer carrier.
8 is a perspective view showing a rotation transmission device to a developer stirring member provided in the developing device in the tandem type printer shown in FIG.
FIG. 9 is a diagram showing a gear engagement state of the rotation transmitting device.
10A and 10B are diagrams showing still another example of a drive transmission device to a developer carrier, wherein FIG. 10A is a rotation input member on the development device side, FIG. 10B is a fixed output member on the drive device side, and FIG. The electromagnet is shown.
FIG. 11 is a perspective view showing an example of an attached state of the fixed output member.
FIG. 12 is a diagram illustrating an example of a conventional drive transmission device for a developer carrier.
FIG. 13 is a diagram showing a gear engagement state of another example of the conventional drive transmission device.
FIGS. 14A and 14B are perspective views showing a state in which a drive gear is attached to a rotating shaft, wherein FIG. 14A shows a case of D-cut engagement, and FIG.
[Explanation of symbols]
12 Image carrier
14 Rotary developing device
22 Developing device
25 Developing roller (developer carrier)
52 roller shaft
53 magnet
54 magnet
55 Magnetic coupling
56 drive unit (drive source)
57 Rotation axis
65 Image carrier
76 Developing roller (developer carrier)
80 magnet
81 magnet
82 magnetic coupling
91 Rotation input member
92 Fixed output member
93 electromagnet
s void

Claims (6)

In a drive transmission device to a developing carrier in an image forming apparatus that rotates the developer carrier to convey the developer, adheres the developer to the image carrier, and develops a latent image on the image carrier,
A drive transmission device for transmitting to a developer carrier, wherein a torque from a drive source is transmitted to the developer carrier via a magnetic coupling. The drive transmission device for a developing carrier according to claim 1, wherein a gap is provided between a pair of magnets constituting the magnetic coupling. The drive transmission device for a development carrier according to claim 1, wherein a motor is used as the drive source. An image forming apparatus, comprising: the drive transmission device for transmitting to a development carrier according to claim 1. A method of transmitting a developer by rotating a developer carrier, transferring the developer, and attaching the developer to the image carrier to develop a latent image on the image carrier, a drive transmission method to the development carrier in an image forming apparatus,
A method for transmitting drive to a developing carrier, comprising transmitting a rotational force from a driving source to the developer carrier via a magnetic coupling. In a drive transmission device to a developing carrier in an image forming apparatus that rotates the developer carrier to convey the developer, adheres the developer to the image carrier, and develops a latent image on the image carrier,
A fixed output member provided with a plurality of electromagnets sequentially turned on and off by a driving device in a circumferential direction; and a rotary input member which rotates under the magnetic action of the fixed output member by the electromagnet to rotate the developer carrier. A drive transmission device to a development carrier, characterized in that:

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