JP4382422B2 - Developing device in image forming apparatus - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing method and apparatus in an image forming apparatus such as a copying machine, a printer, a facsimile, or a composite machine using an electrophotographic method, and more particularly, a two-component developer that charges a nonmagnetic toner using a magnetic carrier. using the charged toner only held on the developing roller, to a current ZoSo location in an image forming apparatus for developing an electrostatic latent image by causing the toner to fly.

  In developing devices in image forming apparatuses such as copiers, printers, facsimiles, or composite machines using electrophotography, toner leakage and scattering from both ends of the developing roller to the outside of the developing device housing are prevented. Various methods have been proposed.

  For example, Patent Documents 1 to 3 show a developing device in which felt or the like is attached to both ends of the developing roller as a seal member for preventing toner leakage, and when the sleeve surface of the developing roller is blasted, Since the toner leaks from between the blasting surface and the felt when used, for example, the toner leakage preventing member is smoothed by removing the unevenness caused by the blasting treatment, or the toner dropping opening below the sealing member. A foamed urethane that is provided with a recess so that the toner that has entered between the seal members can be collected from the opening, or a recess that fits into the end of the developing roller is provided between the developing device side plate and the developing roller end. An apparatus provided with a sealing member is shown.

  Patent Document 4 discloses a developing device in which a magnetic brush made of a magnetic carrier and nonmagnetic toner is formed on a magnet roll, and a thin layer of toner on the magnet roll is formed on the developing roller by a potential difference. In order to prevent the occurrence of afterimages, when toner is supplied and collected by a magnet roll, if the lengths of the magnet roll and the developing roller are the same, the toner on both ends of the developing roller is not collected and an afterimage is generated. Therefore, there is shown a developing device in which the length of the developing roller is made shorter than the length of the magnet roll, and an insulating or higher resistance region than the toner resistance is provided at both ends of the developing roller to prevent toner adhesion to the end surface. ing.

Japanese Patent Laid-Open No. 57-89781 Japanese Patent Laid-Open No. 3-15576 JP-A-4-367880 JP 2003-107898 A

  However, in the developing devices disclosed in Patent Documents 1 to 3, felt or the like is attached to both ends of the developing roller as a toner leakage prevention member, and the unevenness of the blast processing portion at the portion where the toner leakage prevention member is attached is smoothed. Or a toner dropping opening provided on the lower side of the sealing member so that the toner that has entered between the sealing members can be collected from the opening, or the developing roller end between the developing device side plate and the developing roller end. The structure is complicated and increases the number of parts, such as providing a sealing member such as urethane foam provided with a recess to be fitted into the structure. This increases the number of parts and the number of assembly steps, resulting in an increase in cost.

  Further, in the apparatus shown in Patent Document 4, since the toner also flies to the portion where the potential difference occurs in the vicinity of the magnetic brush, the side surface portion of the developing roller is made of a conductive material. However, the toner flies, causing a problem of toner scattering at both ends.

  Therefore, in the present invention, toner adhesion to the side surface of the developing roller and toner intrusion into the developing roller can be prevented by a simple and inexpensive method, and image contamination due to toner scattering and toner leakage and in-machine contamination of the image forming apparatus can be prevented. An object of the present invention is to provide a developing device in the image forming apparatus.

This onset bright for solving the above-utilized conveying bias the magnetic brush formed around the feed roller having a pole member fixed therein, is applied between the rollers while rubbing the development roller and by transferring the toner over the developing roller, performs non-contact developing a latent image on the latent image carrier by toner over layer on the developing roller, the toner remaining on the developing roller, the scraper blade A developing device in an image forming apparatus in which the magnetic brush on the supply roller is in contact with the toner layer on the developing roller without being provided, and the developer is collected and replaced by the peripheral speed difference between both rolls ,
The developing roller quality one shorter than the magnetic brush width width, by utilizing the potential difference between the two rollers only the toner is transferred to the developing roller,
Further, the developing roller is provided with a first support body formed integrally with the sleeve and the shaft between the developing roller surface sleeve and the shaft penetrating the center without providing a wall at the end thereof, supports are formed from entering into the end side of the developing roller position, further ends of the developing roller is characterized that you have been chamfered.

In the developing device, a portion of the bearing that supports the shaft of the developing roller and the shaft of the supply roller is formed with a higher resistance than the toner or an insulating member at a portion receiving the shaft of the developing roller, and is in a non-contact state from the end surface of the developing roller to the inside It has the 2nd support body which forms a space | interval and penetrates and forms the space insulation layer part, It is characterized by the above-mentioned.

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In the developing device in the image forming apparatus according to the present invention, the developing roller and the first support that fixes the position of the developing roller to the rotation shaft are integrally formed by extrusion or pultrusion molding. Features.

Furthermore, the developing device in the image forming apparatus according to the present invention includes the developing roller and a first support that fixes the position of the developing roller to the rotation shaft, and the first support is aligned with the rotation shaft direction. And formed integrally with the developing roller.

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Current ZoSo location in the image forming apparatus according to the present invention, while a magnetic brush composed of magnetic carrier and nonmagnetic toner formed around the feed roller having a fixed magnetic pole member therein, is rubbed on the developing roller both Development method and apparatus in an image forming apparatus in which only a toner is transferred to a developing roller using a conveyance bias applied between rollers, and a latent image on a latent image carrier is non-contact developed with a thin toner layer on the developing roller The developing roller width is made shorter than the magnetic brush width, and only the toner is transferred to the developing roller using the potential difference between the two rollers while the inner peripheral surfaces of both end portions of the developing roller are spatially insulated. The roller width is shorter than the magnetic brush width, and at least both end regions in the developing roller axial direction between the inner peripheral surface side of the developing roller and the rotation shaft are made hollow, or the developing roller width is Beams shorter than the airbrush width and positioned on the inner peripheral side of the developing roller and fixing the developing roller to the rotating shaft are positioned on the inner side of both ends of the developing roller and do not exist in both end regions in the developing roller axial direction. By doing so, toner adhesion to the side of the developing roller and toner entering the developing roller can be prevented by a simple and inexpensive method, and image contamination due to toner scattering and toner leakage and in-machine contamination of the image forming apparatus can be prevented. A developing device in the image forming apparatus can be provided.

  In the developing device in the image forming apparatus according to the present invention, the developing roller and the beam that fixes the position of the developing roller to the rotation shaft are integrally formed by extrusion or pultrusion, so that the axial accuracy is increased. It has good surface accuracy and can be manufactured easily and inexpensively.

  Further, the developing device in the image forming apparatus according to the present invention includes the developing roller and a beam that fixes the position of the developing roller to the rotation shaft, and the beam is aligned with the developing roller along the rotation shaft axis direction. Thus, the developing roller is excellent in strength, less distorted, and less deformed even with one-side gear. Also, by making it integrally, it is possible to cope with large size and small diameter without distortion, and at the time of development, since the bias is equalized and does not vary in the axial direction, the printing quality can be stabilized.

  Further, in the developing device in the image forming apparatus according to the present invention, the base material constituting the developing roller is a conductive material having a high resistance or insulating coating on the outer peripheral surface, and the beam for fixing the position of the developing roller to the rotation shaft is insulated. By forming the outer peripheral surface and the support member as separate members using a material, a developing roller can be easily and inexpensively created.

  In the developing device in the image forming apparatus according to the present invention, it is assumed that a small amount of toner adheres to the tip formed in the R shape by forming the outer peripheral surface edge of the developing roller in a taper or R shape. However, since the distance from the photosensitive member is increased by the R-shaped portion, it does not fly to the photosensitive member and cause image smearing.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

  FIG. 1 is a perspective view for explaining the shape of the developing roller end face of the developing device in the image forming apparatus according to the present invention, and FIG. 2 is for explaining the shape of the developing roller of the developing device in the image forming apparatus according to the present invention. FIG. 3 is a side view, FIG. 3 is a perspective view for explaining the form of the bearings of the developing roller and magnetic roll (supply roller) of the developing device in the image forming apparatus according to the present invention, and FIG. 4 is the development in the image forming apparatus according to the present invention. FIG. 5 is a perspective view of a developing device in the image forming apparatus according to the present invention, and FIG. 6 is a photosensitive image of the developing device in the image forming apparatus according to the present invention. FIG. 7 is a cross-sectional view of an embodiment of the developing device in the image forming apparatus according to the present invention, and FIG. 8 is an image forming apparatus equipped with the developing device according to the present invention. one It is a schematic diagram of 施例.

In the figure, reference numeral 1 is a non-magnetic metal material formed in a cylindrical shape, and a plurality of fixed magnets are arranged inside the sleeve-shaped magnetic roll (supply roller) that can rotate around the fixed magnets, and 2 is a magnetic roll (Supply roller) A developing roller in which a thin layer of toner is formed by a magnetic brush formed on 1, 3 is a photosensitive member, 7 a is a power source for applying a direct current (DC) bias to the developing roller 2, and 7 b is also a developing roller. 2 is a power source for applying an alternating current (AC) bias to 2, 8 is a power source for applying a direct current (DC) bias to the magnetic roll (supply roller) 1, and 9 is a height of a magnetic brush formed on the magnetic roll (supply roller) 1. A blade cutting blade for keeping the thickness constant, 11 is exposure, 12 is a frame of the developing device, 20 is an image forming device, 22 is a paddle mixer that stirs the developer and supplies it to the magnetic roll (supply roller) 1, 23 Similarly, an agitating mixer that conveys and charges the developer while stirring the developer, 25 is a toner sensor that detects the amount of toner in the developing device 50A, and 26 is a partition plate in the developing device. This partition plate is apparent from FIG. As described above, both ends in the longitudinal direction are shorter than the length of the developing device 50A, and the developer can freely pass through both ends. Reference numeral 30 denotes a shaft of the developing roller 2, 31 denotes a shaft of the magnetic roll (supply roller) 1, and 32 denotes a beam (first support) provided inside the developing roller 2 between the shaft 30 and the sleeve of the developing roller. ), 33 developing roller shaft 30, magnetic roll (feed roller) bearings of the shaft 31, 34 is provided to the lid at both end portions of the developing roller 2 without contact, forming a space insulating layer 35 support body (second support), 50A is a black developing device of the image forming apparatus 20, 50B is also a developing device for yellow, 50C are likewise developing device for the cyan, 50D are likewise developing device for magenta, 53 a recording paper The accommodated paper feeding cassette, 54 is an endless belt for transporting recording paper, 56 is a charger for charging the photosensitive member 3, and 57 is for exposing the charged photosensitive member to form a latent image. Exposure device, 8 transfer device for transferring a toner image developed on the recording paper, 59 denotes a fixing device for fixing a toner image on the recording paper to which the toner image is transferred.

  FIG. 8 is a schematic diagram of an embodiment of an image forming apparatus having a developing device according to the present invention. In this image forming apparatus 20, an endless belt 54 fixes a recording sheet from a paper feed cassette 53 to a fixing device 59. The black developing device 50A, the yellow developing device 50B, the cyan developing device 50C, and the magenta developing device 50D are disposed above the belt 54 that conveys the recording paper. Has been. The developing devices 50 (A, B, C, D) are respectively provided with a magnetic roll (supply roller) 1 (A, B, C, D) and a magnetic roll (supply roller) 1 (A, B, C). , D) is disposed adjacent to the developing roller 2 (A, B, C, D), and the photosensitive member 3 (A, B, C, D) is further faced to the developing roller 2 and further the photosensitive member. 3 is provided with a charger 56 (A, B, C, D) and an exposure device 57 (A, B, C, D).

  When a print start signal comes from a control circuit (not shown), the carrier and toner in the developing device 50A are agitated, the toner is frictionally charged and adheres to the carrier surface, and the magnetic roll (supply roller) 1 (A, B, A magnetic brush by a carrier is formed on the surface of C, D), and a thin layer of toner is formed on the developing roller 2 (A, B, C, D). At this time, the recording paper is fed from the paper feed cassette 53 and sent to the belt 54, and the charger 56 is matched with the timing when the recording paper reaches the photosensitive members 3 (A, B, C, D) of the respective colors. (A, B, C, D) charging of the photosensitive member 3, exposure to the photosensitive member 3 by an image signal from the exposure device 57 (A, B, C, D) and formation of a latent image, on the developing roller 2. When the latent image is developed with toner and the recording paper reaches the photoreceptor 3, a transfer bias is applied by the transfer device 58 (A, B, C, D), and the toner image is transferred to the recording paper. The paper is fixed by the fixing device 59 and discharged.

  Next, the developing device 50 will be described. Although four types of developing devices are shown in FIG. 8, the operation is the same, and therefore, a developing device 50A using black toner will be described as a representative example. FIG. 1 is a perspective view for explaining the shape of the end face of the developing roller, FIG. 2 is a side view for explaining the shape of the developing roller, and FIG. 3 explains the form of bearings of the developing roller and the magnetic roll (supply roller). 4 is a partial sectional view for explaining the structure of the bearing of the developing roller, FIG. 5 is a perspective view of the developing device 50A, FIG. 6 is a plan sectional view, and FIG. 7 is a side sectional view.

As is apparent from FIGS. 5 to 7, the developing roller 2 is disposed at a predetermined distance from the photosensitive member 3 in the frame 12 of the developing device 50 </ b> A having a U-shaped cross section. A sleeve-like magnetic roll (which is formed in a cylindrical shape with a nonmagnetic metal material and spaced apart from the developing roller 2 by a plurality of fixed magnets and is rotatable around the fixed magnets ( (Supply roller) 1 is disposed, and the magnetic brush forming region H ₃ of the sleeve is formed to have a dimension longer than the axial width H ₁ of the developing roller 2. Further, an agitating mixer 23 is provided upstream of the magnetic roll (supply roller) 1 with a paddle mixer 22 and a partition plate 26 interposed therebetween. The two-component developer composed of toner and carrier is mixed with the agitating mixer 23 and the paddle mixer 22. Is rotated and rotated between the agitating mixer 23 and the paddle mixer 22 by a portion where there is no partition at both ends of the partition plate 26. For this reason, a magnetic brush is formed on the surface of the magnetic roll (supply roller) 1 by the two-component developer, and the magnetic brush has a constant layer thickness by the cutting blade 9 and contacts the developing roller 2.

  The gap between the cutting blade 9 and the magnetic roll (supply roller) 1 is 0.3 to 1.5 mm, and the gap between the magnetic roll (supply roller) 1 and the developing roller 2 is also about 0.3 to 1.5 mm. It is. The gap between the developing roller 20 and the photoreceptor 3 is 150 to 400 μm, preferably 200 to 300 μm. If it is smaller than 150 μm, it causes fogging. If it is larger than 400 μm, it becomes difficult to cause the toner to fly to the photoreceptor 3, and a sufficient image density cannot be obtained. Further, it becomes a factor that causes selective development.

  On the other hand, between the magnetic roll (supply roller) 1 and the developing roller 2, as shown in FIG. 7, there is a bias in which an alternating current is superimposed on a direct current by a direct current (DC) power supply 7a and an alternating current (AC) power supply 7b. A direct current (DC) power supply 8 applies a direct current bias, and the toner in the magnetic brush on the magnetic roll (supply roller) 1 has a bias potential difference between the direct current (DC) power supply 7a and the direct current (DC) power supply 8 | DC7a. A thin layer of only toner is formed on the developing roller 2 by -DC8 | The toner thin layer on the developing roller 2 varies depending on the resistance of the developer and the rotational speed difference between the developing roller 2 and the magnetic roll (supply roller) 1, but can also be controlled by the above-described potential difference. Yes, when Δ is increased, the toner layer on the developing roller 2 is thickened, and when Δ is decreased, a thin layer is formed. The range of Δ is generally about 100V to 250V.

The toner on the developing roller 2 flies between the photosensitive member 3 with a bias applied to the developing roller 2 by a direct current (DC) power source 7a and an alternating current (AC) power source 7b, and is formed on the photosensitive member 3. Develop the latent image. In order to prevent the toner from scattering, the bias from the alternating current (AC) power supply 7b is applied immediately before the development. Further, the toner remaining on the developing roller 2 that is not used for development is not provided with a special device such as a scraping blade, and the magnetic brush on the magnetic roll (supply roller) 1 is applied to the toner layer on the developing roller 2. The developer is recovered and replaced by the brush effect due to the difference in peripheral speed between the two rolls and the stirring of the magnetic brush by the paddle mixer 22. As described above, since the width H ₁ of the developing roller 2 is shorter than the width H _{3 of} the magnetic brush 1, the magnetic brush 1 is formed over a section longer than the width H _{1 of} the developing roller 2. Since all the toner can be collected, the toner on the developing roller 2 can be reliably replaced.

As shown in FIGS. 1 and 2, the developing roller 2 of the developing device 50A according to the present invention is not provided with a wall at its end, and is formed between the surface sleeve and the shaft 30 penetrating the center. , the support serving beam 32 was extruded formed shape integrally with the sleeves and the shaft 30 is provided. Moreover, the beam 32 is formed from a position entering the inside from the end of the developing roller 2 as apparent from FIG. 1, and the end of the developing roller 2 is chamfered as apparent from FIG. ing. Therefore, the end of the developing roller 2 does not have a flat surface to which the toner adheres, unlike the conventional developing roller, and the end of the upper sleeve is chamfered, so that the toner may also adhere to this end. Absent. Even if a small amount of toner adheres to the chamfered tip, the distance from the photosensitive member 3 is increased by the chamfering, so that it does not fly to the photosensitive member 3 to cause image contamination. Further, since the outer peripheral end faces of the developing roller 2 are chamfered, the electric field emphasis at the end of the developing roller 2 is reduced, and the toner does not fly from the end. Accordingly, the non-printing portion of the photosensitive drum 1 is not stained with toner, and a good image can be obtained.

The material of the developing roller 2 is generally an aluminum drawing tube, but is not limited thereto, and the difference between the outer wall and the inner wall of the developing roller 2, that is, the thickness of the roller has sufficient mechanical strength. Therefore, it is desirable that the surface is thin when the surface to which the toner adheres is considered. The developing roller 2, by making the extrusion forming the form as described above, the surface precision, roughness can make developing roller 2 good good axis accuracy, further axial both end portions of the developing roller 2 Therefore, even a long developing roller can cope with a small diameter without distortion. Further, even during development, since the core passes, the bias is equalized and does not vary in the axial direction, and the print quality is stabilized.

  Further, the developing device of the present invention has a portion that receives the shaft 30 of the developing roller 2 in a bearing portion 33 that supports the shaft 30 of the developing roller 2 and the shaft 31 of the magnetic roll (supply roller) 1 in FIGS. 3 and 4. As shown, it is preferably formed of an insulator or a member having a higher resistance than the toner, and enters from the end face of the developing roller 2 with a slight gap in a non-contact state. It has the support body 34 which forms the part. That is, by providing such a space insulating layer portion, lids are provided at both ends of the developing roller 2 so that the toner does not enter the developing roller 2 and toner scattering can be further prevented.

  Further, as described above, the support 34 is not in contact with the sleeve of the developing roller 2. However, when the support 34 is brought into contact with the sleeve so as to be rotatable, high dimensional accuracy is required for the support 34. There is a demerit that torque increases when accuracy is poor. However, there is no need for such non-contact, and for example, by providing a gap with a gap of about 0.1 to 0.2 mm, the flow of wind is eliminated and toner does not enter.

  In the above description, the case where the developing roller 2 is integrally formed by extrusion has been described as an example. However, the sleeve portion and the shaft 30 and the beam 32 are separate members, and the sleeve portion on the outer peripheral surface has high resistance or insulating coating. Needless to say, the beam 32 as the support may be made of an insulating material and assembled. In this case, the bias to the developing roller 2 is directly applied to the sleeve portion.

  In the above description, the present invention uses a two-component developer that charges a non-magnetic toner using a magnetic carrier in a tandem color image forming apparatus, holds only the charged toner on the developing roller, and removes the toner. Although the case of a developing device that develops an electrostatic latent image by flying is described as an example, it is clear that the present invention can be used for any type of developing device as long as the developing roller does not have a magnet assembly inside. For example, it can be applied to a non-magnetic toner jumping developing device.

  As described above, according to the present invention, both rollers are formed while sliding a magnetic brush made of a magnetic carrier and a non-magnetic toner formed around a supply roller having a magnetic pole member fixed inside the developing roller. In a developing method and apparatus in an image forming apparatus in which only a toner is transferred to a developing roller using a conveyance bias applied in between and a latent image on a latent image carrier is non-contact developed with a thin toner layer on the developing roller. The developing roller width is made shorter than the magnetic brush width, and only the toner is transferred to the developing roller using the potential difference between the two rollers while the inner peripheral surfaces of both end portions of the developing roller are spatially insulated. The width is shorter than the width of the magnetic brush, and at least both end regions in the developing roller axial direction between the inner peripheral surface side of the developing roller and the rotation shaft are made hollow, or the developing roller width is magnetic. The beam that is shorter than the lash width and that is positioned on the inner peripheral side of the developing roller and that fixes the developing roller to the rotating shaft is positioned on the inner side of both ends of the developing roller and does not exist in both end regions in the axial direction of the developing roller. By this, toner adhesion to the side of the developing roller and toner intrusion into the developing roller can be prevented with a simple and inexpensive method, and image contamination due to toner scattering and toner leakage and in-machine contamination of the image forming apparatus can be prevented. A developing device in the image forming apparatus can be provided.

  In the developing device in the image forming apparatus according to the present invention, the developing roller and the beam that fixes the position of the developing roller to the rotation shaft are integrally formed by extrusion or pultrusion, so that the axial accuracy is increased. It has good surface accuracy and can be manufactured easily and inexpensively.

  Further, the developing device in the image forming apparatus according to the present invention includes the developing roller and a beam that fixes the position of the developing roller to the rotation shaft, and the beam is aligned with the developing roller along the rotation shaft axis direction. Thus, the developing roller is excellent in strength, less distorted, and less deformed even with one-side gear. Also, by making it integrally, it is possible to cope with large size and small diameter without distortion, and at the time of development, since the bias is equalized and does not vary in the axial direction, the printing quality can be stabilized.

  Further, in the developing device in the image forming apparatus according to the present invention, the base material constituting the developing roller is a conductive material having a high resistance or insulating coating on the outer peripheral surface, and the beam for fixing the position of the developing roller to the rotation shaft is insulated. By forming the outer peripheral surface and the support member as separate members using a material, a developing roller can be easily and inexpensively created.

  In the developing device in the image forming apparatus according to the present invention, it is assumed that a small amount of toner adheres to the tip formed in the R shape by forming the outer peripheral surface edge of the developing roller in a taper or R shape. However, since the distance from the photosensitive member is increased by the R-shaped portion, it does not fly to the photosensitive member and cause image smearing.

  According to the present invention, toner adhesion to the side surface of the developing roller and toner intrusion into the developing roller can be prevented by a simple and inexpensive method, and image contamination due to toner scattering and toner leakage and in-machine contamination of the image forming apparatus can be prevented. The developing method and apparatus in the image forming apparatus can be provided.

It is a perspective view for demonstrating the shape of the developing roller end surface of the developing device in the image forming apparatus which becomes this invention. It is a side view for demonstrating the shape of the developing roller of the developing device in the image forming apparatus which becomes this invention. It is a perspective view for demonstrating the form of the bearing of the developing roller of a developing device and the magnetic roll (supply roller) in the image forming apparatus which becomes this invention. FIG. 4 is a partial cross-sectional view for explaining a structure of a bearing of a developing roller of the developing device in the image forming apparatus according to the present invention. 1 is a perspective view of a developing device in an image forming apparatus according to the present invention. It is a schematic diagram explaining the relationship between the photosensitive member of the developing device and the developing device in the image forming apparatus according to the present invention. 1 is a cross-sectional view of an embodiment of a developing device in an image forming apparatus according to the present invention. 1 is a schematic diagram of an embodiment of an image forming apparatus including a developing device according to the present invention.

1 Magnetic roll (supply roller)
2 Developing roller 30 Developing roller shaft 31 Magnetic roll (supply roller) shaft 32 Beam

Claims (4)

The magnetic brush formed around the feed roller having a pole member fixed therein, by using a conveying bias applied between both rollers while rubbing the development roller is transferred to toner over the developing roller, a latent image on the latent image carrier by toner over layer on the developing roller performs a non-contact development, the toner remaining on the developing roller, a magnetic brush on the supply roller without providing a scraper blade development A developing device in an image forming apparatus that contacts a toner layer on a roller and collects and replaces the developer by a difference in peripheral speed between both rolls ,
The developing roller quality one shorter than the magnetic brush width width, by utilizing the potential difference between the two rollers only the toner is transferred to the developing roller,
Further, the developing roller is provided with a first support body formed integrally with the sleeve and the shaft between the developing roller surface sleeve and the shaft penetrating the center without providing a wall at the end thereof, supports are formed from entering into the end side of the developing roller position, further ends of the developing roller, a developing device in an image forming apparatus according to claim that you have been chamfered. In the developing device, a portion of the bearing that supports the shaft of the developing roller and the shaft of the supply roller is formed with a higher resistance than the toner or an insulating member at a portion receiving the shaft of the developing roller, and is in a non-contact state from the end surface of the developing roller to the inside 2. The developing device in an image forming apparatus according to claim 1 , further comprising: a second support member that forms a space insulating layer portion with a gap therebetween. 3. The development in an image forming apparatus according to claim 2 , wherein the developing roller and the first support that fixes the position of the developing roller to the rotation shaft are integrally formed by extrusion or pultrusion molding. apparatus. The developing roller and a first support that fixes the position of the developing roller to the rotation shaft. The first support is formed integrally with the developing roller along the rotation shaft. 4. The developing device in the image forming apparatus according to claim 2, wherein the developing device is an image forming apparatus.

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