JP5344300B2 - Developing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress vibration of a developing roll. <P>SOLUTION: The developing device includes: the developing roll 22 including a magnet roll shaft 31 having a magnetized part 32 having magnetic poles and a shaft center part 33 provided on both sides of the magnetized part 32 and projecting from a housing 21, a sleeve 41 arranged around the magnetic roll shaft 31, and a supporting shaft 43 rotatably supported by a first bearing 23 provided in the housing 21 and attached to one end of the sleeve 41 to project from the housing 21; a gear train 47 provided on the outside of the housing 21 and transmitting rotational force to the supporting shaft 43; and a gear cover 50 attached to the housing 21 while housing the gear train 47, and configured by integrally forming a holding part 60 in which the shaft center 33 is fixed and which holds a space between a photoreceptor drum and the developing roll 22. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

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

  In a developing device used in an image forming apparatus such as a copying machine or a fax machine, an electrostatic latent image is formed on the surface of the photosensitive drum by exposing the surface of the photosensitive drum with a laser beam modulated according to image data. The electrostatic latent image is developed by a developing device to form a toner image, and the toner image is transferred to a transfer sheet to obtain an image.

  Here, the developing device includes a housing that forms the outer shape of the device, and a gear train that transmits rotation to a sleeve of a developing roll (an example of a developing unit). The developing roll has a mag roll shaft having a plurality of magnetic poles on the surface, and a cylindrical sleeve provided to be rotatable around the mag roll shaft.

  The toner is supplied from the developing roll to the photosensitive drum, and the electrostatic latent image is developed as described above to obtain a toner image.

  Examples of techniques for reducing the density unevenness of the developed toner image include those disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2006-098833) and Patent Document 2 (Japanese Patent Laid-Open No. 2003-122078). .

JP 2006-098483 A JP 2003-122078 A

  An object of the present invention is to provide a developing device and an image forming apparatus that can suppress vibration of the developing means.

  In order to solve the above-mentioned problems, the developing device according to the first aspect of the present invention includes a container having an outer shape of the apparatus, a magnetized portion having a magnetic pole on the surface, and both sides of the magnetized portion. A magnet structure having an axial core projecting from the cylindrical structure, a cylindrical rotating body arranged around the magnet structure with a space therebetween, and a first bearing provided in the housing body. And a developing means for developing the electrostatic latent image by supplying a developer to the photosensitive member, and provided on one end of the rotating member and protruding from the receiving member. Provided, a transmission means for transmitting a rotational force to the rotational force transmission section, a housing means for housing the transmission means and being attached to the housing body, the shaft core portion being fixed, and the photosensitive member and the developing means. One holding part is held at a predetermined interval. And transmitting means accommodating body formed, and having a.

  According to a second aspect of the present invention, there is provided a developing device according to the present invention, comprising: a container having an outer shape; a magnetized portion having a magnetic pole on the surface; and a magnet structure having axial core portions provided on both sides of the magnetized portion. A cylindrical rotating body disposed around the magnet structure at an interval, and a rotational force transmitting portion attached to one end of the rotating body and projecting from the container, and a developer is applied to the photosensitive member. A developing means for supplying and developing the electrostatic latent image; a transmission means provided on the outside of the container; for transmitting a rotational force to the rotational force transmission portion; And a transmission means containing body integrally formed with a holding part for fixing the shaft core part and holding the photosensitive member and the developing means at a predetermined interval. The first portion provided between the end and the rotating body is provided in the container. Is rotatably supported by a bearing, is rotatably supported by the second bearing further end portion is provided on the transmission means housing body, characterized in that.

  The invention according to claim 3 is the invention according to claim 1 or 2, characterized in that the natural frequency of the magnet structure is different from the excitation frequency of the transmission means.

  In order to solve the above problems, an image forming apparatus according to a fourth aspect of the present invention is an electrostatic latent image formed by the developing device according to any one of the first to third aspects and a developer supplied from the developing device. And a transfer member for transferring the visible image to a recording medium.

  According to the first aspect of the present invention, vibration of the developing unit can be suppressed.

  According to the second aspect of the present invention, vibration of the developing unit can be suppressed.

  According to the invention of claim 3, the vibration of the developing means is further suppressed.

  According to the fourth aspect of the present invention, an image with reduced density unevenness can be obtained.

1 is a diagram illustrating a configuration of an image forming apparatus according to a first embodiment of the present invention. It is a figure which shows the structure of the image forming unit used for the image forming apparatus of FIG. FIG. 3 is a cross-sectional view schematically showing a part of a developing roll constituting a developing device of an image forming unit. It is a front view which shows the external appearance of the housing of a developing device. It is a perspective view which shows the external appearance of the one end side of the housing of a developing device. It is the perspective view which looked at the external appearance of the housing of a developing device from the one end side. It is a disassembled perspective view which shows the housing and gearwheel cover of a developing device. It is a figure which shows the inner side of the gearwheel cover of a developing device. FIG. 6 is a perspective view showing the developing device in a state where a gear cover is attached to a housing. FIG. 6 is a cross-sectional view schematically showing a part of a developing roll constituting a developing device used in an image forming apparatus according to a second embodiment of the present invention. It is sectional drawing which showed typically the part of the image development roll in the modification of the image development apparatus in the 2nd Embodiment of this invention.

  (First embodiment)

  Hereinafter, an embodiment as an example of the present invention will be described in detail with reference to the drawings. Note that components having the same function are denoted by the same reference symbols throughout the drawings for describing the embodiment, and the repetitive description thereof will be omitted.

  FIG. 1 is a diagram showing a configuration of an image forming apparatus 100 according to the first embodiment of the present invention. As shown in the figure, the image forming apparatus 100 forms an image on a paper P (an example of a recording medium) using toner (an example of a developer), and is yellow (Y), magenta (M), cyan ( C) Four image forming units 1Y, 1M, 1C, and 1K that form toner images (an example of a visible image) of each color of black and black (K), and a plurality of rolls 2 and the direction of arrow A And the intermediate transfer belt 3 that rotates to the intermediate transfer belt 3 and the secondary transfer that secondarily transfers the toner image primarily transferred from the image forming units 1Y, 1M, 1C, and 1K to the intermediate transfer belt 3 onto the sheet P conveyed by the conveyance guide 4. A transfer roll 5 (an example of a transfer unit), a fixing device 6 for fixing the toner image secondarily transferred to the paper P to the paper P by heating and pressurizing, and a belt cleaner 7 for cleaning the intermediate transfer belt 3. Preparation There. Further, a control device 8 for controlling the image forming operation as described above is provided.

  Next, the configuration of the image forming units 1Y, 1M, 1C, and 1K will be described. Here, FIG. 2 is a diagram showing a configuration of the image forming unit 1K.

  As shown in FIG. 2, the image forming unit 1K includes a photosensitive drum 11K (an example of a photosensitive member), a contact-type charging roll 12K that charges the photosensitive drum 11K to a predetermined charging potential, and a charged photosensitive member. An exposure device 13K that forms an electrostatic latent image by irradiating the body drum 11K with light, and a black toner image (an example of a visible image) is supplied to the surface of the photosensitive drum 11K by supplying black toner to the electrostatic latent image. A developing device 20K to be formed, a primary transfer roll 15K for primary transfer of a toner image to the intermediate transfer belt 3, and a cleaning device 16K for removing toner remaining on the surface of the photosensitive drum 11K are provided.

  The controller 8 sets a charging potential having a preset value, and charges the surface of the photosensitive drum 11K by applying a voltage between the photosensitive drum 11K and the charging roll 12K. Further, the control device 8 sets an exposure potential of a preset value, and controls the exposure device 13K based on the image data corresponding to black among the image data of each color of YMCK to light the photosensitive drum 11K. And an electrostatic latent image is formed by lowering the irradiated portion from the charged potential to the exposure potential.

  The image forming units 1Y, 1M, and 1C have the same configuration as that of the image forming unit 1K except that the color of the toner is different from that of the image forming unit 1K. For this reason, in the following description, the components of the image forming units 1Y, 1M, 1C, and 1K are denoted by “Y”, “M”, “C”, and “K”, respectively. If they are distinguished but need not be distinguished, these symbols are not attached. For example, the developing device of the image forming unit 1Y is expressed as “developing device 20Y”, and the developing devices 20Y, 20M, 20C, and 20K are expressed as “developing device 20” when they are not distinguished.

  Next, the structure of the developing device 20 will be described. Here, FIG. 3 is a cross-sectional view schematically showing a part of the developing roll 22 (an example of the developing means) constituting the developing device 20.

  The developing device 20 includes a housing 21 (an example of a container) that forms the outer shape of the device, a developing roll 22 that is housed in the housing 21 and is rotatably supported, and a gear train 47 that transmits rotational force from a motor. A gear cover 50 (an example of a transmission means housing) that is accommodated and attached to the housing 21 is provided.

  The developing roll 22 includes a mag roll shaft 31 (an example of a magnet structure) and a cylindrical sleeve 41 (an example of a rotator) that is rotatably supported around the mag roll shaft 31.

  The mag roll shaft 31 has a columnar magnetized portion 32 having a magnetic pole on the surface, and a shaft core portion 33 that is formed to protrude from both sides (only one is shown) of the magnetized portion 32 and has a smaller diameter than the magnetized portion 32. And have. A flange portion 34 is formed between the magnetized portion 32 and the shaft core portion 33.

  Further, the sleeve 41 is disposed so as to surround the outer periphery of the magnetized portion 32 of the mag roll shaft 31 and spaced from the magnetized portion 32. On both sides of the sleeve 41 (only one is shown), a stepped and cylindrical support shaft 43 (an example of a rotational force transmitting portion) that supports the sleeve 41 is provided so as to protrude in the axial direction of the sleeve 41.

  An annular step 45 is formed on the outer periphery of the support shaft 43, and an annular step 46 is formed on the inner periphery on the sleeve 41 side.

  The first bearing 23 is press-fitted into the mounting hole 21 </ b> B formed in the side surface 21 </ b> A of the housing 21, and the support shaft 43 of the sleeve 41 is fitted inside the first bearing 23, so that the annular step 45 It is positioned. Further, a mag gear 47 </ b> A that forms a part of the gear train 47 is fixed to the distal end side of the support shaft 43 of the sleeve 41 in a state of being prevented from rotating with respect to the support shaft 43. A plurality of positioning projections 21C (only one is shown) protrude from the side surface 21A of the housing 21. Further, cylindrical screw receivers 21D and 21E are formed so as to protrude (see FIG. 6). Since the gear train 47 is not provided on the opposite side of the support shaft 43 to the illustrated side, it does not have to protrude from the housing 21.

  The third bearing 24 is press-fitted into the annular step portion 46 of the sleeve 41, and the shaft core portion 33 is press-fitted inside the third bearing 24 and is positioned by the flange portion 34 of the mag roll shaft 31. The As illustrated, the shaft portion 33 protrudes from the side surface 21 </ b> A of the housing 21. Note that the shaft core portion (not shown) on the other side may protrude from the housing 21 or may not protrude.

  In this structure, when a rotational force is transmitted from an external motor (not shown) to the mag gear 47 </ b> A of the gear train 47, the sleeve 41 rotates as the support shaft 43 rotates.

  A plurality of positioning recesses 51 (only one is shown) that fits with the positioning protrusions 21 </ b> C described above are formed in a portion that contacts the side surface 21 </ b> A of the housing 21 of the gear cover 50, and an axial core portion that protrudes from the housing 21. A fixing hole 52 is formed at a position corresponding to 33 to which the shaft portion 33 is press-fitted and fixed.

  When the gear cover 50 is attached to the housing 21, the positioning recesses 51 of the gear cover 50 are fitted into the positioning protrusions 21 </ b> C of the housing 21, and the shaft core portion 33 is inserted into the fixing hole 52, and a screw (not shown). Are screwed into the screw receivers 21D and 21E. Thereby, the gear cover 50 is fixed to the housing 21.

  The shaft core 33 need not be press-fitted into the fixing hole 52, and may be fixed with, for example, a screw or a pin.

  A holding portion 60 is integrally formed with the gear cover 50. The holding portion 60 has a shape protruding toward the photosensitive drum 11 (see FIGS. 8 and 9). If the developing device 20 is mounted on the image forming apparatus 100, image formation on the photosensitive drum 11 is performed. It is pressed against the end that does not contribute to the. As shown in FIG. 4, a tracking member T having the same function as the holding portion 60 is provided on the other end side of the housing 21.

  The holding unit 60 formed integrally with the gear cover 50 attached to the housing 21 in which the tracking member T and the developing roll 22 are accommodated is pressed against the photosensitive drum 11, whereby the photosensitive drum 11 and the developing roll 22 are pressed. Is held at a predetermined interval.

  Here, when the gear train 47 rotates in order to rotate (drive) the mag roll shaft 31, the driving reaction force received by the holding unit by the rotation is directly transmitted to the mag roll shaft 31 and the sleeve 41, and the developing roll 22 vibrates. As a result, the gap between the mag roll shaft 31 and the sleeve 41 becomes unstable and the amount of toner supplied from the developing roll 22 to the photosensitive drum 11 fluctuates. As a result, the electrostatic latent image formed on the photosensitive drum 11 is changed. The developed toner image may cause density unevenness.

  On the other hand, in the present embodiment, the holding portion 60 is integrally formed with the gear cover 50 and the rigidity is improved as compared with the case where the two are separated, and the gear cover 50 has a mag roll shaft. Since the shaft core 33 of 31 is fixed, the rigidity of the holding part 60 and the mag roll shaft 31 is improved by the rigidity of the gear cover 50. As a result, the driving reaction force received by the holding portion is not easily transmitted to the mag roll shaft 31, and vibrations generated in the developing roll 22 are suppressed.

  Therefore, according to the image forming apparatus of the present embodiment, the interval between the mag roll shaft 31 and the sleeve 41 is stabilized, and the fluctuation of the toner supply amount from the developing roll 22 to the photosensitive drum 11 is suppressed, and the photosensitive drum. The toner image obtained by developing the electrostatic latent image formed on the toner image 11 is reduced in density unevenness and good image quality is obtained.

  Further, since the holding portion 60 is integrally formed with the gear cover 50, the positional relationship between the mag roll shaft 31 and the holding portion 60 is improved, and the photosensitive drum 11 and the developing roll 22 are spaced at a predetermined interval. Retained.

  Here, the excitation frequency of the gear train 47 (defined by the number of rotations and the number of teeth of each gear constituting the gear train 47) and the natural frequency of the mag roll shaft 31 (the length of the magnetized portion 32, If they coincide with each other), the vibration of the developing roller 22 is amplified and the density unevenness is deteriorated in the formed image. End up.

  Therefore, if the excitation frequency of the gear train 47 and the natural frequency of the mag roll shaft 31 are made different, the amplification of the vibration of the developing roll 22 due to resonance is eliminated, and the vibration of the developing roll 22 is further suppressed.

  Note that the vibration frequency of the gear train 47 and the natural frequency of the mag roll shaft 31 are different from each other because the element that defines the vibration frequency of the gear train 47 and the natural frequency of the mag roll shaft 31 are defined. By adjusting the elements to be played. However, it is not easy to change the number of rotations and the number of teeth of each gear constituting the gear train 47, or to change the length of the magnetized portion 32 of the mag roll shaft 31, the diameter of the shaft core portion 33, and the material. There are cases. Therefore, by changing the length of the shaft core portion 33, the excitation frequency of the gear train 47 and the natural frequency of the mag roll shaft 31 can be easily made different.

  Next, the housing 21 of the developing device 20 will be described with reference to FIGS.

  In FIG. 4, the developing roll 22 is accommodated in the housing 21. The housing 21 further accommodates a conveying member (not shown) that conveys toner to the developing roll 22. The tracking member T described above is provided on one end side (the left side in the drawing) of the housing 21.

  As shown in FIGS. 5 and 6, the gear train 47 and the gears 47 </ b> A to 47 </ b> E constituting the gear train 47 are rotatable on the side on which the gear cover 50 is attached. A total of five shaft portions (support shaft 43 and shaft portions 25B to 25E) to be supported are provided. The rotational force transmitted from the outside to the gear 47B is transmitted in the order of the gear 47B, the gear 47C, the gear 47D, and the gear 47E, and is transmitted to the mag gear 47A attached to the support shaft 43 of the developing roll 22. Then, the support shaft 43 rotates with the sleeve 41 by the rotation of the mag gear 47A.

  Among the shaft portions 25B to 25E, the tip of the shaft portion 25B is formed in a conical pointed shape, and the tip of the shaft portion 25D is formed in a deformed circle shape in which the opposite side surfaces of the peripheral surface are notched. A female screw portion 25E1 is formed on the end surface of the portion 25E. The shaft portion 25D is a shaft that rotates a transport member for transporting toner.

  Next, the shape of the gear cover 50 attached to the housing 21 will be described with reference to FIGS. 7 and 8.

  The gear cover 50 includes a base portion 50A that has a triangular shape as a whole, a wall portion 50B that is located on the long side of the base portion 50A and rises from one side surface of the base portion 50A toward the housing 21, and a short portion of the base portion 50A. A protrusion 50E that is positioned at the apex of the side and rises from one side surface of the base 50A toward the housing 21 and into which the screw receiver 21E is inserted, and a recess that is positioned in the middle of the wall 50B and into which the screw receiver 21D is inserted 50D, for example, formed of ABS resin containing glass fiber (acrylonitrile, butadiene, styrene copolymer synthetic resin), POM (polyacetal, polyoxymethylene), or the like. Yes.

  Further, the mounting surface of the gear cover 50 is formed with a step for accommodating the shaft core portion 33 protruding from the side surface 21 </ b> A of the housing 21, the shaft portions 25 </ b> B to 25 </ b> E, the gear train 47, and the like. Define the space.

  Screw holes 55E and 55D into which screws M (FIG. 9) are inserted are formed on the base 50A side of the protrusion 50E and the recess 50D. A substantially C-shaped positioning recess 51 into which the positioning protrusion 21C of the housing 21 is inserted is formed at the end of the wall 50B.

  Furthermore, a plurality of through holes are formed in the base portion 50A. That is, a positioning hole 56B is formed at a position facing the shaft portion 25B, a positioning hole 56D having a deformed circular shape is formed at a position facing the shaft portion 25D, and a position facing the shaft portion 25E is formed at the base portion 25A. An insertion hole 58 </ b> E is formed, and a fixing hole 52 is formed at a position facing the shaft core portion 33.

  Next, a state where the gear cover 50 is attached to the housing 21 will be described with reference to a perspective view of FIG.

  When the gear cover 50 is attached to the side surface 21A of the housing 21, the positioning convex portion 21C of the housing 21 is fitted with the positioning concave portion 51, the shaft portion 25B is inserted into the positioning hole 56B, and the shaft portion 25D is inserted into the positioning hole 56D. Is done. Thereby, the gear cover 50 is firmly fixed to the housing 21 by three-point support. Further, the distance between the shafts of the gears is set to a predetermined distance.

  At this time, the shaft core portion 33 is press-fitted into the fixing hole 52 and protrudes from the fixing hole 52. Further, the screw receiver 21D is viewed through the screw hole 55D and is not shown hidden in the drawing, but the screw receiver 21E is viewed through the screw hole 55E. Furthermore, the screw M is screwed into the screw receivers 21D and 21E through the screw holes 55D and 55E (not shown), and the screw M is screwed into the female screw portion (not shown) formed in the shaft portion 25E, thereby the gear cover. 50 is fixed to the housing 21. As described above, the gear cover 50 has the holding portion 60 that is integrally formed in a shape protruding toward the photosensitive drum 11.

  (Second Embodiment)

  FIG. 10 is a cross-sectional view schematically showing a part of the developing roll 22 constituting the developing device 20 of the image forming apparatus according to the second embodiment of the present invention.

  In FIG. 10, in the developing device 20 of the present embodiment, unlike the developing device 20 of the first embodiment, an annular protrusion 61 is formed on the inner wall of the gear cover 50, and on the inner periphery of the protrusion 61. The second bearing 62 is press-fitted. The end portion of the support shaft 43 that supports the sleeve 41 of the developing roll 22 is made rotatable by the second bearing 62. Further, the shaft core portion 33 of the mag roll shaft 31 is not fixed to the gear cover 50. Further, as shown in the drawing, the end portion of the support shaft 43 and the sleeve 41 are rotatably supported by a first bearing 23 provided in the housing 21. Other portions are the same as those of the developing device 20 in the first embodiment.

  As described above, the support shaft 23 is supported by the second bearing 62 in addition to the first bearing 23, so that shaft blurring when the support shaft 23 rotates is suppressed. Therefore, vibration generated in the developing roll 22 is further suppressed. As a result, according to the image forming apparatus equipped with such a developing device 20, a high-quality image in which the density unevenness of the toner image obtained by developing the electrostatic latent image formed on the photosensitive drum 11 is further reduced can be obtained. can get.

  In addition, since it is not necessary to fix the shaft core part 33 to the gear cover 50 in this way, the freedom degree of the length setting of the shaft core part 33 improves. That is, the shaft core portion 33 is freely set from a minimum length supported by the third bearing 24 as shown in FIG. 10 to a length protruding from the gear cover 50 as shown in FIG. Is done.

  As described above, making the excitation frequency of the gear train 47 different from the natural frequency of the mag roll shaft 31 can be easily realized by changing the length of the shaft portion 33. And since the length of the axial part 33 is set freely in this way like this Embodiment, the setting which makes the excitation frequency of the gear train 47 and the natural frequency of the mag roll shaft 31 differ. Becomes easier.

  In the image forming apparatus corresponding to the paper P up to A3 size, generally, the length of the mag roll shaft 31 (the length including the shaft core portion 33 and the magnetized portion 32) is about 400 mm. The natural frequency is 75 Hz. And if the structure of this Embodiment is employ | adopted, the axial center part 33 will become about 40 mm short at the maximum, and, thereby, a natural frequency is moved to 157 Hz at maximum. That is, the natural frequency is adjusted over a width of 82 Hz.

  Although the invention made by the present inventor has been specifically described based on the embodiment, the embodiment disclosed in this specification is an example in all respects and is limited to the disclosed technology. Should not be considered. That is, the technical scope of the present invention should not be construed restrictively based on the description in the above-described embodiment, but should be construed according to the description of the scope of claims. All modifications are included without departing from the technical scope equivalent to the described technique and the gist of the claims.

  In the above description, the case where the present invention is applied to a printer which is an example of an image forming apparatus is shown. However, the present invention is applied to an image forming apparatus such as a facsimile, a copier, or a complex machine in which these functions are combined. May be.

  Various recording media such as paper, film, postcard, cash and the like on which an image is formed are applied.

DESCRIPTION OF SYMBOLS 20 Developing apparatus 21 Housing 22 Developing roll 23 Support shaft 23 1st bearing 24 2nd bearing 31 Mag roll shaft 32 Magnetized part 33 Axle core part 41 Sleeve 43 Support shaft 47 Gear train 47A Mag gear 47B-47E Gear 50 Gear Cover 60 Holding portion 62 Third bearing 100 Image forming apparatus

Claims (4)

A container forming the outer shape of the device;
A magnet structure having a magnetized portion having a magnetic pole on the surface and an axial core portion provided on both sides of the magnetized portion and projecting from the container, and a cylindrical shape disposed around the magnet structure with a space therebetween And a rotating force transmitting portion that is rotatably supported by a first bearing provided on the housing and attached to one end of the rotating body and protrudes from the housing, and is developed on the photosensitive member. Developing means for supplying an agent to develop the electrostatic latent image;
A transmission means provided on the outer side of the container, for transmitting the rotational force to the rotational force transmission unit;
Accommodates the transmission means and is attached to the accommodation body. The transmission means accommodation is integrally formed with a holding portion for fixing the shaft core portion and holding the photosensitive member and the developing means at a predetermined interval. Body,
A developing device comprising: A container forming the outer shape of the device;
A magnet structure having a magnetized portion having a magnetic pole on the surface and axial core portions provided on both sides of the magnetized portion, a cylindrical rotating body disposed around the magnet structure, and the A developing means that includes a rotational force transmitting portion that is attached to one end of the rotating body and protrudes from the container, and that supplies a developer to the photosensitive body to develop the electrostatic latent image;
A transmission means provided on the outer side of the container, for transmitting the rotational force to the rotational force transmission unit;
Accommodates the transmission means and is attached to the accommodation body. The transmission means accommodation is integrally formed with a holding portion for fixing the shaft core portion and holding the photosensitive member and the developing means at a predetermined interval. Having a body,
The rotational force transmitting portion is rotatably supported by a first bearing provided in the housing body between the end portion and the rotating body, and further has a second end portion provided in the transmitting means housing body. It is supported rotatably by bearings,
A developing device. The natural frequency of the magnet structure is different from the excitation frequency of the transmission means.
3. The developing device according to claim 1, wherein A developing device according to any one of claims 1 to 3,
A photosensitive member in which an electrostatic latent image is developed by a developer supplied from the developing device to become a visible image;
A transfer portion for transferring the visible image to a recording medium;
An image forming apparatus comprising:

Images