JP2014178498A - Angular position adjustment method, manufacturing method of development device and development device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an angular position adjustment method capable of adjusting an angular position of a magnet roller in a developer carrier into a desired range, and to provide a manufacturing method of a development device and the development device.SOLUTION: The angular position adjustment method includes the steps of: disposing a unit of a development device 4 at an adjustment device having drive means whose rotation angle can be detected, and magnetic flux detection means capable of detecting magnetic flux generated by a magnet roller; detecting a magnetization position reference of a magnetic pole in a circumferential direction of the magnet roller; detecting an angular position of a specific magnetic pole of the magnet roller with respect to the magnetization position reference from information indicating relation between an acquired rotation angle of the magnet roller and magnetic flux density; disposing the specific magnetic pole of the magnet roller at a predetermined angular position in a circumferential direction of corresponding one of developer carriers 41A, 41B, by the drive means, according to the detected angular position of the specific magnetic pole with respect to the magnetization position reference; and fixing the magnet roller to the developer carrier so as not to be rotatable.

Description

  The present invention relates to a method for adjusting the angular position of a magnet roller in a developing device used in an image forming apparatus such as a copying machine, a laser beam printer, a facsimile machine, and a printing device using an electrophotographic method or an electrostatic recording method, and the manufacturing of the developing device. The present invention relates to a method and a developing device.

  In an electrophotographic image forming apparatus, an electrostatic latent image formed on the surface of a photoconductor as an image carrier is developed as a toner image with toner which is a colored powder to which a charge is applied by a developing device. Then, the toner image is transferred to a transfer material such as paper and further fixed, whereby an output product is obtained.

  In general, the developing device is provided with a developer container containing toner (one-component developer) or toner and a carrier (two-component developer) as a developer, and is provided rotatably at an opening of the developer container. And a developer carrying member that carries and conveys the developer to a portion facing the photosensitive member.

  In addition, a developing device has been proposed in which a plurality of developer carriers are arranged in the developer transport direction to increase the number of developments and the development area, thereby stabilizing the development performance and improving the image quality (patent) Reference 1). In particular, in a configuration in which a developer containing a magnetic material is used and a plurality of developer carriers are continuously arranged, in order to obtain a stable developer application state on the developer carrier, a magnet roller in the developer carrier is provided. The arrangement, order, strength, etc. of the magnetic poles may be defined (Patent Documents 2 and 3). Further, in a hybrid development system in which toner is supplied from a developer carrier to a plurality of toner carriers, a method of adjusting the angular position of the magnetic pole of a magnet roller in the developer carrier with respect to each toner carrier has been proposed (patent) Reference 4).

JP 2004-29569 A JP 2007-240619 A JP 2010-72160 A JP 2011-85823 A

  In a developing device having a plurality of developer carriers, the application of the developer to the developer carrier located downstream in the transport direction of the developer and the regulation of the amount are formed between the two developer carriers. Some are performed by a gap and a magnetic field formed in the gap (see Patent Documents 2 and 3).

  In this way, when using the gap between the developer carriers and the magnetic field, compared to the case where the developer is applied to the developer carrier and the amount thereof is regulated by the magnetic blade fixedly supported, It may be difficult to stably maintain a uniform application state. The reason is considered as follows. In other words, when using the gap between the developer carriers and the magnetic field, a magnetic field higher than the surroundings can be formed by arranging the magnetic poles facing the gap between the developer carriers, but the magnetic blade is placed. Compared with the concentrated magnetic field formed in this case, the density per area is low. Therefore, the length of the magnetic spike of the developer that is applied on the developer carrying member arranged on the downstream side in the transport direction of the developer and whose amount is regulated tends to be unstable. Further, the gap between the developer carrying members has a larger amplitude of fluctuation of the distance than that of the fixed blade, and the fluctuation cycle is not uniform. This is because the surfaces of the two developer carriers are relatively large, and the surfaces of the two developer carriers are likely to be proximately or apart from each other due to the shake of the two rotating members that move in opposite directions and the overlapping of the roundness. Because.

  Actually, the uniformity of the developer applied to the developer carrier disposed downstream in the developer transport direction is the magnetic field formed in the gap region formed between the two developer carriers, that is, the gap between them. It is greatly affected by the magnetic flux density and angle of the magnetic poles facing toward.

  For this reason, in order to achieve the desired performance by using a plurality of developer carriers, it is sometimes necessary to employ parts with accuracy much higher than the current standard.

  In addition, when trying to adjust the angular position of the magnet roller with higher accuracy, generally the same problem may occur.

  Accordingly, an object of the present invention is to provide an angular position adjusting method and a developing method capable of adjusting the angular position of the magnet roller in the developer carrying body to a desired range while suppressing an increase in accuracy required for the parts. An apparatus manufacturing method and a developing device are provided.

  The above object is achieved by the angular position adjusting method, the developing device manufacturing method, and the developing device according to the present invention. In summary, the first aspect of the present invention includes a developer carrying member for carrying and carrying a developer, a core material, and a plurality of magnetic poles arranged around a rotation center axis of the core material. In a method for adjusting the angular position of a magnet roller in a developing device having a unit provided with a magnet roller disposed in a hollow portion of the agent carrier, the magnet roller connected to the core member of the magnet roller is driven to rotate. An adjustment device comprising: a drive unit capable of detecting a rotation angle; and a magnetic flux detection unit capable of detecting a magnetic flux generated by the magnet roller at a predetermined position in the circumferential direction of the developer carrier. Disposing a unit; detecting a magnetic pole magnetization position reference in a circumferential direction of the magnet roller; and From the information indicating the relationship between the rotation angle of the magnet roller and the magnetic flux density obtained by detecting the magnetic flux generated by the magnet roller by the magnetic flux detection means while rotating the roller, the specific magnetic pole of the magnet roller Detecting the angular position of the magnet roller with respect to the magnetized position reference; and according to the detected angular position of the specific magnetic pole with respect to the magnetized position reference, An angular position adjusting method comprising: disposing at a predetermined angular position in a circumferential direction of the developer carrying member; and fixing the magnet roller to the developer carrying member in a non-rotatable manner.

  According to a second aspect of the present invention, there are provided two developer carrying members arranged close to each other for carrying and transporting the developer, and each arranged around a core material and a rotation center axis of the core material. In a method for adjusting the angular position of a magnet roller in a developing device having a unit including a plurality of magnetic poles and two magnet rollers disposed in a hollow portion of a corresponding developer carrier among the two developer carriers. A driving means connected to the core material of the target magnet roller of at least the two magnet rollers and capable of rotating the magnet roller; and a driving means capable of detecting a rotation angle; and the at least one of the two developer carriers. The magnetic flux generated by the target magnet roller can be detected at a predetermined position in the circumferential direction of the developer carrier corresponding to the target magnet roller. A step of disposing at least the unit of the developing device in an adjusting device having a magnetic flux detecting means; and detecting a magnetization position reference of a magnetic pole in a circumferential direction of the target magnet roller of the two magnet rollers And rotating the target magnet roller acquired by detecting the magnetic flux generated by the target magnet roller by the magnetic flux detection means while rotating the target magnet roller by the driving means. From the information indicating the relationship between the angle and the magnetic flux density, the angular position of the specific magnetic pole adjacent to the proximity of the two developer carriers among the magnetic poles of the target magnet roller with respect to the magnetization position reference is detected. And a step of controlling the driving means according to an angular position of the specific magnetic pole detected with respect to the magnetization position reference. Then, the step of disposing the specific magnetic pole of the target magnet roller at a predetermined angular position in the circumferential direction of the corresponding developer carrier; and the developer carrier corresponding to the target magnet roller An angular position adjusting method comprising: fixing the body to the body so as not to rotate.

  According to a third aspect of the present invention, there is provided a developing device manufacturing method comprising adjusting the angular position of the developer carrying member corresponding to the magnet roller in the circumferential direction by the angular position adjusting method of the present invention.

  According to a fourth aspect of the present invention, there is provided the developing apparatus wherein the angular position in the circumferential direction of the developer carrying member corresponding to the magnet roller is adjusted by the angular position adjusting method of the present invention.

  According to the present invention, the angular position of the magnet roller in the developer carrying member can be adjusted to a desired range while suppressing an increase in accuracy required for the parts.

1 is a schematic cross-sectional view of an image forming apparatus including a developing device according to an embodiment of the present invention. 1 is a schematic cross-sectional view of a developing device according to an embodiment of the present invention. FIG. 2 is a schematic perspective view of a developing sleeve unit in an embodiment of the present invention. It is typical sectional drawing of the image development sleeve and magnet roller in one Example of this invention. It is a schematic diagram of the adjustment apparatus of the angular position of the magnet roller in one Example of this invention. It is typical sectional drawing of the principal part of the adjustment apparatus for demonstrating the adjustment method of the angular position of the magnet roller in one Example of this invention. It is a flowchart figure which shows an example of the adjustment procedure of the angular position of a magnet roller in one Example of this invention. It is a schematic diagram of the adjustment apparatus of the angular position of the magnet roller in the other Example of this invention. It is typical sectional drawing of the principal part of the adjustment apparatus for demonstrating the adjustment method of the angular position of the magnet roller in the other Example of this invention. It is a flowchart figure which shows an example of the adjustment procedure of the angular position of the magnet roller in the other Example of this invention. It is a schematic diagram for demonstrating the subject regarding the angular position of a magnet roller.

  Hereinafter, the angular position adjusting method, the developing device manufacturing method, and the developing device according to the present invention will be described in more detail with reference to the drawings.

Example 1
1. Image Forming Apparatus First, an image forming apparatus provided with a developing device according to an embodiment of the present invention will be described. FIG. 1 is a schematic cross-sectional view illustrating a schematic configuration of a main part of the image forming apparatus according to the present exemplary embodiment. The image forming apparatus 100 according to the present exemplary embodiment is a laser beam printer using an electrophotographic method.

  The image forming apparatus 100 includes a photosensitive drum 1 that is a drum (cylindrical) type electrophotographic photosensitive member (photosensitive member) as an image carrier. The photosensitive drum 1 is rotationally driven in the direction of arrow R1 in the figure. Around the photosensitive drum 1, the following units are arranged in order along the rotation direction. First, a primary charger 2 is disposed as a charging unit. Next, an exposure device (laser scanner) 3 as an exposure unit is arranged. Next, a developing device 4 as a developing unit is arranged. Next, a post charger 9 is disposed as a toner charge amount adjusting means. Next, a primary transfer roller 61 that is a roller-type primary transfer member serving as a primary transfer unit is disposed. Next, a drum cleaner 8 as a photosensitive member cleaning means is disposed.

  The image forming apparatus 100 also includes a data processing unit 10 that converts image data into serial data in a format suitable for exposure conversion by the exposure apparatus (laser scanner) 3.

  Further, the image forming apparatus 100 has an endless belt-like intermediate transfer belt 62 as an intermediate transfer member at a position facing the photosensitive drum 1. The intermediate transfer belt 62 is wound around a driving roller 64A, a secondary transfer counter roller 64B, and a tension roller 64C as a plurality of stretching rollers with a predetermined tension. The primary transfer roller 61 is disposed at a position facing the photosensitive drum 1 on the inner peripheral surface side of the intermediate transfer belt 62. The primary transfer roller 61 is pressed against the photosensitive drum 1 via the intermediate transfer belt 62 to form a primary transfer portion (primary transfer nip) N1 where the intermediate transfer belt 62 and the photosensitive drum 1 are in contact with each other. . On the outer peripheral surface side of the intermediate transfer belt 62, a secondary transfer roller 63, which is a roller-type secondary transfer member as a secondary transfer means, is disposed at a position facing the secondary transfer counter roller 64B. The secondary transfer roller 63 is pressed against the secondary transfer counter roller 64B via the intermediate transfer belt 62, and a secondary transfer portion (secondary transfer nip) where the intermediate transfer belt 62 and the secondary transfer roller 63 come into contact with each other. N2 is formed. Further, on the outer peripheral surface side of the intermediate transfer belt 62, a belt cleaner as an intermediate transfer member cleaning unit is located downstream of the secondary transfer portion N2 and upstream of the primary transfer portion N1 in the moving direction of the intermediate transfer belt 62. 65 is arranged. The transfer unit 6 is configured by the intermediate transfer belt 62, the primary transfer roller 61, the belt cleaner 65, and the like that are stretched around the stretch roller.

  In addition, the image forming apparatus 100 fixes a toner image on the transfer material P (not shown) that supplies a transfer material P such as paper to the secondary transfer portion N2, and the transfer material P that has passed through the secondary transfer portion N2. A heating and pressure fixing device (fixing device) 7 is provided as fixing means.

  In this embodiment, the photosensitive drum 1 has an outer diameter of 108 mm in which an amorphous silicon layer is formed on the surface of an aluminum cylinder as a photosensitive layer. The photosensitive drum 1 is rotationally driven in the direction of arrow R1 in the drawing by a drive motor (not shown) as a drive means at a peripheral speed of 700 mm / sec during image formation.

  The primary charger 2 charges the surface of the rotating photosensitive drum 1 substantially uniformly to a predetermined potential having a predetermined polarity (negative polarity in this embodiment). Then, an electrostatic image is formed on the photosensitive drum 1 by the scanning of the laser beam L whose intensity is modulated based on the signal generated by the data processing unit 10 by the exposure device (laser scanner) 3 and the rotation of the photosensitive drum 1. (Electrostatic latent image) is formed.

  The developing device 4 includes two developing sleeves 41A and 41B as a plurality of developer carriers. The two developing sleeves 41 </ b> A and 41 </ b> B are disposed in close proximity to and face the photosensitive drum 1. Then, a developing bias is applied to the two developing sleeves 41A and 41B from a developing high voltage circuit (not shown) as a developing bias applying means, whereby the electrostatic image on the photosensitive drum 1 is developed. The developer used in this example is a negative polarity (negative chargeability) obtained by adding styrene acrylic and polyester resin as a binder and adding magnetite, black pigment, charge control agent, etc. as a magnetic material, and then pulverizing and classifying. ) One-component magnetic developer (toner). The toner is replenished into the developing container 40 from a toner bottle (not shown) through the toner supply unit 45, and is brought close to the two developing sleeves 41A and 41B by the stirring and conveying members 43A, 43B, 43C and 43D. Supplied. In this embodiment, the electrostatic image on the photosensitive drum 1 is developed by reversal development using the toner carried on the two developing sleeves 41A and 41B and conveyed. That is, the exposed portion on the photosensitive drum 1 where the absolute value of the potential is lowered by being exposed after being uniformly charged is charged to the same polarity as the charging polarity (negative polarity in this embodiment) of the photosensitive drum 1. The electrostatic image is developed as a toner image by attaching the toner. The developing device 4 will be described in detail later.

  The toner image formed on the photosensitive drum 1 is corrected by the post charger 9 to a charge amount suitable for transfer according to the temperature and humidity environment, and then conveyed to the primary transfer portion N1.

  In this embodiment, the intermediate transfer belt 62 is an endless belt based on a polyimide film, and tension application and shift control are performed by the tension rollers 64A, 64B, and 64C. The intermediate transfer belt 62 is rotationally driven at a peripheral speed of 700 mm / sec in the direction of arrow R4 in the drawing by transmitting a rotational driving force to the driving roller 64A.

  In the primary transfer unit N1, a primary transfer bias is applied to a primary transfer roller 61 from a primary transfer high-voltage circuit (not shown) serving as a primary transfer bias application unit, whereby a toner image on the photosensitive drum 1 is transferred to an intermediate transfer belt. First transferred onto 62.

  The toner image transferred to the intermediate transfer belt 62 is secondarily transferred to a transfer material P such as paper guided to the secondary transfer portion N2 in the secondary transfer portion N2. At this time, a secondary transfer bias is applied to the secondary transfer roller 63 from a secondary transfer high voltage circuit (not shown) as a secondary transfer bias applying unit.

  The transfer material P onto which the toner image has been transferred is fixed by the fixing device 7. The fixing device 7 includes a heating roller 71 and a pressure roller 72, and the transfer material P is sandwiched and conveyed by the two rollers to fix an unfixed toner image on the transfer material P. Thereafter, the transfer material P on which the toner image is fixed is output outside the main body of the image forming apparatus 100.

  The toner remaining on the photosensitive drum 1 after the primary transfer step (primary transfer residual toner) is removed from the surface of the photosensitive drum 1 by the drum cleaner 8 and collected. The secondary transfer residual toner remaining on the intermediate transfer belt 62 after the secondary transfer process is removed from the surface of the intermediate transfer belt 62 by the belt cleaner 65 and collected.

2. Next, the developing device 4 of this embodiment will be described in more detail. FIG. 2 is a schematic cross-sectional view showing the developing device 4 of this embodiment in more detail. The developing device 4 includes a developing container 40 that stores a developer. The two developing sleeves 41 </ b> A and 41 </ b> B as a plurality of developer carriers are arranged in the developing container 40 along the rotational direction of the photosensitive drum 1 so as to be close to the photosensitive drum 1 with a predetermined gap (gap). Arranged in the opening. The developing sleeve 41A located on the upstream side in the developer transport direction by the two developing sleeves 41A and 41B at the portion facing the photosensitive drum 1 is referred to as an upstream developing sleeve 41A. Further, the developing sleeve 41B located on the downstream side in the same direction is referred to as a downstream developing sleeve 41B.

  The upstream developing sleeve 41A and the downstream developing sleeve 41B are arranged so as to be close to each other with a predetermined gap (gap), and are driven to rotate in the same direction. That is, the upstream developing sleeve 41A is rotationally driven in the direction of the arrow R2 in the drawing. Further, the downstream developing sleeve 41B is rotationally driven in the direction R3 in the drawing. Accordingly, in the proximity portion (delivery portion) G between the upstream developing sleeve 41A and the downstream developing sleeve 41B, the developing sleeves 41A and 41B move in opposite directions. Further, in the facing portion (upstream developing portion) DA between the upstream developing sleeve 41A and the photosensitive drum 1, the upstream developing sleeve 41A and the photosensitive drum 1 move in the same direction. Further, in the facing portion (downstream developing portion) DB between the downstream developing sleeve 41B and the photosensitive drum 1, the downstream developing sleeve 41B and the photosensitive drum 1 move in the same direction.

  In this embodiment, the developer conveyance direction by the upstream developing sleeve 41A and the downstream developing sleeve 41B at the portion facing the photosensitive drum 1 is substantially the same as the moving direction of the photosensitive drum 1.

  In the developing container 40, the stirring and conveying members 43A, 43B, 43C, and 43D are arranged as described above. When the toner amount sensor 44 detects that the amount of toner in the developing container 40 has decreased below a predetermined amount during development, the toner in the toner supply unit 45 is replenished into the developing container 40. The toner in the developing container 40 is transported toward the upstream and downstream developing sleeves 41A and 41B by the stirring and transport members 43A, 43B, and 43C.

  Each of the developing sleeves 41A and 41B is a substantially cylindrical body made of aluminum which is a nonmagnetic member. In this embodiment, the upstream developing sleeve 41A has an outer diameter of 32 mm and is driven to rotate at a peripheral speed of 850 mm / sec. The downstream developing sleeve 41B has an outer diameter of 24 mm and is driven to rotate at a peripheral speed of 630 mm / sec. The lengths of the developing sleeves 41A and 41B in the longitudinal direction (rotation axis direction) are substantially the same. The surface of each of the developing sleeves 41A and 41B is subjected to a blasting process or a film obtained by mixing and curing a phenol resin, crystalline graphite, and carbon at a certain weight ratio, for example. The ability to impart charge to the sheath toner can be adjusted.

  Inside the hollow portion of the upstream developing sleeve 41A, an upstream magnet roller 47A having a plurality of magnetic poles as magnetic field generating means is disposed substantially coaxially. A downstream magnet roller 47B having a plurality of magnetic poles as magnetic field generating means is disposed substantially coaxially inside the hollow portion of the downstream developing sleeve 41B.

  In the present embodiment, the upstream magnet roller 47A is provided with magnetic poles N1, N2, N3, N4, S1, S2, S3, S4 having magnetic field patterns around the rotation center axis of a core material (core metal) 50A described later. Has been. These magnetic poles are arranged in the order of N1, S1, N2, S2, S3, N3, N4, and S4 in the direction opposite to the rotation direction of the upstream developing sleeve 41A. In FIG. 2, the magnetic pole N1 of the upstream magnet roller 47A is a magnetic pole (upstream developing main pole) disposed substantially at a position opposite to the upstream developing portion DA. In FIG. 2, the magnetic pole N4 is a magnetic pole (upstream delivery pole) that forms a magnetic field in a proximity portion (delivery portion) G between the upstream development sleeve 41A and the downstream development sleeve 41B.

  In the present embodiment, the downstream magnet roller 47B is provided with magnetic poles N1, N2, N3, S1, and S2 having a magnetic field pattern around a rotation center axis of a core material (core metal) 50B described later. These magnetic poles are arranged in the order of N1, S1, N2, N3, and S2 in the direction opposite to the rotation direction of the downstream developing sleeve 41B. In FIG. 2, the magnetic pole N1 of the downstream magnet roller 47B is a magnetic pole (downstream developing main pole) disposed almost at a position opposite to the downstream developing portion DA. Further, in FIG. 2, the magnetic pole S1 is a magnetic pole (downstream delivery pole) that forms a magnetic field in a proximity portion (delivery portion) G between the upstream development sleeve 41A and the downstream development sleeve 41B.

  Note that the position of the magnetic pole is represented by the angle (angular position) of the position indicating the maximum value of the magnetic flux density in the normal direction of the magnetic pole. Hereinafter, this angular position is also simply referred to as “maximum position”.

  The gaps between the upstream and downstream developing sleeves 41A and 41B and the photosensitive drum 1 at the upstream and downstream development positions DA and DB are 150 to 400 μm, respectively.

  Further, a layer thickness regulating blade 42 as a developer regulating member is disposed so as to face the upstream developing sleeve 41A with a predetermined gap (gap). The layer thickness regulating blade 42 is provided over substantially the entire area in the longitudinal direction of the upstream developing sleeve 42 on the upstream side of the upstream developing section DA in the rotation direction of the upstream developing sleeve 41A. The coat thickness of the toner carried on the upstream developing sleeve 41A is regulated by the layer thickness regulating blade 42 by the magnetic force of the upstream magnet roller 47A.

  On the other hand, the toner carried on the downstream side 41B is formed in a gap (delivery part) G formed between the upstream side development sleeve 41A and the downstream side development sleeve 41B, and in this gap (delivery part) G. Coat thickness is regulated by magnetic field. In the transfer part G, a magnetic field is formed between the upstream transfer pole N4 of the upstream magnet roller 47A and the downstream transfer pole S1 of the downstream magnet roller 47B, which is a different pole. A gap (gap) between the upstream developing sleeve 41A and the downstream developing sleeve 41B in the transfer section G is 200 to 400 μm. In the present embodiment, in particular, the thickness is 350 ± 40 μm at the center in the longitudinal direction (rotational axis direction) of the upstream and downstream developing sleeves 41A and 41B.

  In this embodiment, at the time of image formation, a developing bias in which a DC bias and an AC bias are superimposed is applied to each developing sleeve 41A, 41B from a developing bias power source. Thus, the electrostatic image is developed in a non-contact manner by causing the toner to fly to the photosensitive drum 1 side.

3. As described above, in this embodiment, the magnetic poles of the upstream and downstream magnet rollers 47A and 47B that are different from each other with respect to the proximity region of the upstream and downstream developing sleeves 41A and 41B (see FIG. The upstream and downstream delivery poles) are opposed. As a result, a magnetic field is formed, and application of the toner carried on the downstream developing sleeve 41B and regulation of the amount thereof are performed. In such a developing device 4, there is a strong correlation particularly between the uniformity of the toner application state on the downstream developing sleeve and the angular positions of the upstream and downstream delivery poles. Then, the width of the angular position of the upstream and downstream transfer poles allowed to keep the toner application state uniform from the width of the tolerance of the angular position at the time of magnetization with respect to the magnetization position reference of each magnet roller May be narrower. As a result, it may be difficult to uniformly apply the toner particularly onto the downstream developing sleeve.

  This will be further described with reference to FIG. In the figure, a photoconductor 501 is rotationally driven at a peripheral speed of 700 mm / sec in the direction of arrow R1 in the figure. The upstream developing sleeve 502A has an outer diameter of 32 mm and is driven to rotate in the direction of arrow R2 in the drawing at a peripheral speed of 850 mm / sec. The upstream side developing sleeve 502A includes an upstream side magnet roller 503A. The downstream developing sleeve 502B has an outer diameter of 24 mm and is driven to rotate in the direction of arrow R3 in the drawing at a peripheral speed of 630 mm / sec. A downstream magnet roller 503B is included in the downstream developing sleeve 502B. The gap between the two developing sleeves 502A and 502B is 350 ± 40 μm at the center in the longitudinal direction (rotational axis direction) of each developing sleeve 502A and 502B. The magnetic poles that form a magnetic field in the gap between the two developing sleeves 502A and 502B are the magnetic pole α that is the N pole of the upstream magnet roller 503A and the magnetic pole β that is the S pole of the downstream magnet roller 503B. The maximum value of the magnetic flux density in the normal direction of the magnetic pole α is 85 ± 5 mT. Further, the maximum position of the magnetic pole α is arranged at an angle ξ in the rotational direction of the upstream developing sleeve 501A with respect to the plane X1 connecting the rotational center of the photoreceptor 501 and the rotational center of the upstream developing sleeve 502A. The The maximum value of the magnetic flux density in the normal direction of the magnetic pole β is 82 ± 5 mT. Further, the maximum position of the magnetic pole β forms an angle ω with respect to the plane X2 connecting the rotation center of the photosensitive member 501 and the rotation center of the downstream development sleeve 502B in the direction opposite to the rotation direction of the downstream development sleeve 502B. Arranged. When the magnetic pole α, which is the N pole, and the magnetic pole β, which is the S pole, are arranged close to each other, the surfaces of the developing sleeves 502A and 502B move to the proximity region between the upstream developing sleeve 502A and the downstream developing sleeve 502B. A magnetic field is formed in which the magnetic lines of force are directed in a direction substantially perpendicular to the direction in which the magnetic field is generated. In this configuration, a single-component magnetic developer (toner) is used as the developer, and the angle range of the magnetic pole α allowed to realize a uniform developer application state on the downstream side development sleeve 502B is ξ ± 1. The angle region of 5 ° and the magnetic pole β was ω ± 2.5 °.

  On the other hand, at present, in a general magnet roller, the angle of the maximum position of the formed magnetic pole with respect to the magnetization position reference (for example, the reference shape such as the reference surface formed on the core material supporting the magnetic body) The accuracy is about ± 3 °.

  There are the following methods for fixing the magnet roller to the support member and the developing device. That is, a D-cut surface (reference surface) or the like is formed as a magnetization position reference at the end in the longitudinal direction (rotation axis direction) of the core member of the magnet roller, and this D-cut surface is projected on a monitor screen by a camera or the like. Then, the magnet roller is rotated and fixed so that the D-cut surface is within a predetermined range (for example, ± 0.5 °) with respect to a desired angle. However, in such a method for adjusting the angular position of the magnet roller, it may be difficult to uniformly apply the developer onto the developer carrier on the downstream side in the developer transport direction. As described above, the magnetic pole that forms a magnetic field between the developer carrying members, which is allowed to keep the developer application state more uniform than the tolerance width at the time of magnetization with respect to the magnetization position reference of the magnet roller. This is the case when the width of the angular position is narrower.

4). Developer Carrier Unit FIG. 3 is a perspective view schematically showing a developing sleeve unit 5 as a developer carrier unit constituting a part of the developing device 4 of this embodiment. FIG. 3 shows the developer carrier unit 5 as viewed from the inside of the developer container 40. FIG. 4 is a schematic cross-sectional view of the upstream developing sleeve 41A and the upstream magnet roller 47A included therein as an example.

  The developer carrier unit 5 supports the upstream and downstream development sleeves 41A and 41B disposed opposite to the photosensitive drum 1, and the upstream and downstream development sleeves 41A and 41B. Consists of parts for fixing. In the following description, the left side (right side in FIG. 3) of the developer carrier unit 5 extending in the left-right direction from the photosensitive drum 1 side is the left side of the developer carrier unit 5, and the opposite side (FIG. The left side in 3) is the right side.

  The upstream magnet roller 47A is rotatably supported with respect to the upstream developing sleeve 41A at both ends in the longitudinal direction (rotational axis direction) of the core member 50A constituting the rotational shaft. A fixing member 49A constituting a fixing means is fitted and integrated with an end portion on the left side in the longitudinal direction of the core member 50A of the upstream magnet roller 47A. Then, a fixing screw 49A2 constituting the fixing means is passed through a long hole portion 49A1 formed in the fixing member 49A, and is fixed to a left support member 48L described later. Thereby, the upstream magnet roller 47A is fixed to the upstream developing sleeve 41A so as not to rotate. Similarly, the downstream magnet roller 47B is rotatably supported with respect to the downstream developing sleeve 41B at both ends in the longitudinal direction (rotation axis direction) of the core member 50B constituting the rotation shaft. A fixing member 49B constituting a fixing means is fitted and integrated with the left end portion of the downstream side magnet roller 47B in the longitudinal direction of the core member 50B. Then, a fixing screw 49B2 constituting the fixing means is passed through an elongated hole portion 49B1 formed in the fixing member 49B, and is fixed to a left side support member 48L described later. Accordingly, the downstream magnet roller 47A is fixed to the downstream developing sleeve 41B so as not to rotate.

  The upstream and downstream developing sleeves 41A and 41B have both longitudinal end portions thereof connected to the right support member 48R and the left support member 48L as support members via bearing bearings and metal rings (not shown). It is supported rotatably. A gear 51 as a drive receiving portion is fixed to the right end portion in the longitudinal direction of the upstream developing sleeve 41A. When the driving force from the driving gear train provided in the apparatus main body of the image forming apparatus 100 is transmitted to the gear 51, the upstream developing sleeve 41A is rotationally driven. A belt 52 as a drive transmission member is wound around the right end of each of the upstream and downstream developing sleeves 41A and 41B in the longitudinal direction. By this belt 52, the driving force transmitted to the upstream developing sleeve 41A via the gear 51 is transmitted to the downstream developing sleeve 41B, and the downstream developing sleeve 41B is rotationally driven.

  The developing device 4 is configured by fixing the developing sleeve unit 5 to the developing container 40 via the left and right support members 48L and 48R.

  In the present embodiment, the left ends 54A and 54B of the core members 50A and 50B of the upstream and downstream magnet rollers 47A and 47B are connected to the drive units 201A and 201B of the adjusting device 200 described later. Function as a unit (see FIG. 5). In this embodiment, the upstream and downstream developing sleeves 41 </ b> A and 41 </ b> B are partially exposed from the opening of the developing container 40 to the photosensitive drum 1 side. This exposed portion functions as an exposed portion 53 that exposes the peripheral surfaces of the upstream and downstream developing sleeves 41A and 41B for detection of magnetic flux by magnetic flux sensors 202A and 202B of the adjusting device 200 described later (see FIG. 5). ).

5. Next, a method for adjusting the angular positions of the magnet rollers 47A and 47B in this embodiment will be described.

  FIG. 5 is a schematic diagram illustrating a configuration of a main part of an adjustment device (adjustment tool, adjustment jig) 200 for adjusting the angular position of the magnet roller in the present embodiment. FIG. 6 is a diagram illustrating a main part of the adjusting device 200 in the direction orthogonal to the rotation axis of the upstream and downstream developing sleeves 41A and 41B for explaining the adjustment procedure of the angular position of the magnet roller in the present embodiment. It is typical sectional drawing.

  In the present embodiment, the angular positions of the upstream and downstream magnet rollers 47A and 47B are set in a state where the developing sleeve unit 5 shown in FIG. The adjusting device 200 includes upstream and downstream drive units 201A and 201B as drive means, upstream and downstream magnetic flux sensors 202A and 202B as magnetic flux detection means, left and right positioning frames 203L and 203R (left side only). As shown). The adjustment device 200 includes left and right pressurizing units 204L and 204R (only the right side is illustrated), a controller 205, and an operation unit 206 as pressurizing means.

  The developing sleeve unit 5 is attached to the adjusting device 200 as follows. That is, the left and right support members 48L and 48R are abutted against the abutting portions 231L and 231R (only the left side is illustrated) of the left and right positioning frames 203L and 203R of the adjusting device 200, respectively. The left and right support members 48L and 48R are pressed toward the abutting portions 231L and 231R by the left and right pressurizing portions 204L and 204R, respectively. Thereby, the developing sleeve unit 5 is positioned with respect to the adjusting device 200. The left and right pressure members 204L and 204R have contact portions 241L and 241R (only the left side is shown) that contact the left and right support members 48L and 48R, respectively. The left and right pressurizing parts 204L and 204R are pressing springs 242L and 242R as urging means for urging the contact parts 241L and 241R toward the left and right support members 48L and 48R, respectively (left side only). As shown).

  The upstream magnetic flux sensor 202A is on the reference plane X1 connecting the rotation center of the upstream developing sleeve 41A of the positioned developing sleeve unit 5 and the rotation center of the virtual photosensitive drum 1, and the surface position of the virtual photosensitive drum 1 It arrange | positions so that it may be located on S. The reference plane X1 or the position (reference position) on the outer peripheral surface of the upstream developing sleeve 41A that intersects the reference plane X1 determines the predetermined angular position of the upstream magnet roller 47A in the circumferential direction of the upstream developing sleeve 41A. It becomes the standard. On the other hand, the downstream magnetic flux sensor 202B is on the reference plane X2 connecting the rotation center of the downstream developing sleeve 41B of the positioned developing sleeve unit 5 and the rotation center of the virtual photosensitive drum 1 and of the virtual photosensitive drum 1. It arrange | positions so that it may be located on the surface position S. The reference plane X2 or the position (reference position) on the outer peripheral surface of the downstream developing sleeve 41B that intersects the reference plane X2 determines a predetermined angular position of the downstream magnet roller 47B in the circumferential direction of the downstream developing sleeve 41B. It becomes the standard. In the present embodiment, the upstream and downstream magnetic flux sensors 202A and 202B are disposed at substantially the center in the longitudinal direction of the upstream and downstream developing sleeves 41A and 41B. As the upstream and downstream magnetic flux sensors (magnetic sensors, Hall elements) 202A and 202B, for example, TCS10DPU manufactured by Toshiba Corporation can be suitably used.

  The upstream drive unit 201A is a drive unit that rotates the upstream magnet roller 47A and can detect the rotation angle. The upstream drive unit 201A includes a stepping motor 211A, which is a drive source, and a speed reduction connecting part (not shown) that decelerates and transmits the driving force of the stepping motor 211A to the upstream magnet roller 47A. The upstream drive unit 201A is connected to the left end 54A of the core member 50A of the upstream magnet roller 47A when the developing sleeve unit 5 is mounted on the adjustment device 200. Similarly, the downstream drive unit 201B, which is a drive unit that can detect the rotation angle for rotationally driving the downstream magnet roller 47B, includes a stepping motor 211A, a speed reduction connecting unit (not shown), and the like. The downstream drive unit 201B is connected to the left end 54B of the core member 50B of the downstream magnet roller 47B when the developing sleeve unit 5 is mounted on the adjustment device 200. The upstream and downstream drive units 201A and 201B can independently rotate and drive the upstream and downstream magnet rollers 47A and 47B with an accuracy of 0.5 ° / step. The upstream and downstream drive units 201A and 201B can rotate and drive the upstream and downstream magnet rollers 47A and 47B for each step angle smaller than the accuracy of the angular position required for the magnetic poles described later. it can. For example, a pulse motor unit (M42SP-13NK manufactured by Mitsumi Electric Co., Ltd.) can be suitably used as the upstream and downstream drive units 201A and 201B.

  The controller 205 which is a control circuit unit includes a CPU 251 as a calculation control unit, a memory 252 as a storage unit, and the like. The CPU 251 controls the operation of the adjustment device 200 according to the program stored in the memory 252 and executes the adjustment operation of the angular position of the magnet roller. As will be described in detail later, the CPU 251 can drive the upstream and downstream drive units 201A and 201A for each predetermined rotation angle. Further, the detection results of the upstream and downstream magnetic flux sensors 202A and 202B are input to the controller 205. Then, the CPU 251 correlates the information related to the rotation angles of the upstream and downstream magnet rollers 47A and 47B by the upstream and downstream drive units 201A and 201B with the information related to the detected magnetic flux, and stores the memory 252. Can be memorized. In addition, an operation unit 206 is connected to the controller 205 in order to input an instruction to start the adjustment procedure to the controller 205 and to perform necessary display.

  Next, a method for adjusting the angular position of the magnet roller using the adjusting device 200 as described above will be described. In this embodiment, the method for manufacturing the developing device 4 includes this adjustment method.

  In the present embodiment, a case will be described in which the angular positions of the delivery poles of the upstream and downstream magnet rollers 47A and 47B that particularly affect the uniformity of the toner application state on the downstream developing sleeve are described. Further, in this embodiment, the upstream and downstream magnet rollers 47A and 47B have magnetic poles that do not intersect with other magnetic poles, including the maximum range of the magnetic flux density in the normal direction. In the upstream magnet roller 47A, the upstream developing main pole N1 shown in FIG. 2 is the magnetic pole. In the downstream magnet roller 47B, the downstream developing main pole N1 shown in FIG. 2 is the magnetic pole. In this embodiment, these magnetic poles are used as the reference positions for the magnetized positions of the upstream and downstream magnet rollers 47A and 47B, which will be described in detail later.

  Therefore, in order to facilitate understanding, in FIG. 6, as the magnetic pole of the upstream magnet roller 47A, the upstream delivery pole N2 (A) of interest (corresponding to the magnetic pole N4 in FIG. 2), the upstream development main pole N1 Only (A) (corresponding to the magnetic pole N1 in FIG. 2) is shown. Similarly, in FIG. 6, as the magnetic poles of the downstream magnet roller 47B, the downstream transfer pole S1 (B) of interest (corresponding to the magnetic pole S1 in FIG. 2), the downstream development main pole N1 (B) (in FIG. 2). Only the magnetic pole N1) is shown.

  The arrows of the magnetic poles N1 (A) and N2 (A) in the figure are directions from the rotation center of the upstream developing sleeve 41A toward the position (maximum position) indicating the maximum value of the magnetic flux density in the normal direction of each magnetic pole. (Planar direction passing through the rotation center of the upstream developing sleeve 41A and the maximum position of each magnetic pole) is shown. Further, the arrows N1 (B) and S1 (B) in the figure indicate directions from the rotation center of the downstream developing sleeve 41B toward the position (maximum position) indicating the maximum value of the magnetic flux density in the normal direction of each magnetic pole ( The plane direction passing through the rotation center of the downstream developing sleeve 41B and the maximum position of each magnetic pole) is shown. Also, X1 in the figure is a reference plane that serves as a reference for the angular position of the magnetic pole of the upstream magnet roller 47A in the circumferential direction of the upstream developing sleeve 41A. The rotation center of the upstream developing sleeve 41A and the rotation of the photosensitive drum 1 Pass through the center. Also, X2 in the figure is a reference plane that serves as a reference for the angular position of the magnetic pole of the downstream magnet roller 47B in the circumferential direction of the downstream developing sleeve 41B, and the rotation center of the downstream developing sleeve 41B and the rotation of the photosensitive drum 1 Pass through the center.

  The upstream delivery pole N2 (A) of the upstream magnet roller 47A forms a magnetic field with the downstream delivery pole S1 (B) of the downstream magnet 47B. This magnetic field is directed in a direction substantially perpendicular to the moving direction of each of the two developing sleeves 41A and 41B in the proximity region (transfer section) G between the two developing sleeves 41A and 41B. Further, the upstream developing main pole N1 (A) and the downstream developing main pole N1 (B) are respectively the areas where the upstream developing sleeve 41A, the downstream developing sleeve 41B and the photosensitive drum 1 are closest to each other (upstream in FIG. 2). Magnetic flux directed toward the photosensitive drum 1 is generated in the side developing section DA and the downstream developing section DB).

  In this embodiment, the center of the design value of the angle ψ formed by the maximum position of the upstream developing main pole N1 (A) and the maximum position of the upstream transfer pole N2 (A) in the circumferential direction of the upstream magnet roller 47A and the magnetization The tolerance width at this time is ψ = 74 ± 3 °. Further, the design center of the angle φ formed by the maximum position of the downstream development main pole N1 (B) and the maximum position of the downstream transfer pole S1 (B) in the circumferential direction of the downstream magnet roller 47B and the tolerance width are φ = 86 ± 3 °. That is, in the present embodiment, the tolerance width when the upstream and downstream developing rollers 47A and 47B are magnetized is ± 3 °.

  Further, in the configuration of the developing device 4 of the present embodiment, the following experimental results are obtained as conditions for maintaining a good state of toner application to the downstream developing sleeve 41B. First, the angle formed by the reference plane X1 in the circumferential direction of the upstream developing sleeve 41A and the maximum position of the upstream delivery pole N2 (A) is within a range of 71.5 ± 1.5 ° (clockwise in FIG. 6). It is required to be in In addition, the angle formed by the reference plane X2 in the circumferential direction of the downstream developing sleeve 41B and the maximum position of the downstream transfer pole S1 (B) is within a range of 89 ± 2.5 ° (counterclockwise in FIG. 6). It is required to be. That is, in the present embodiment, the allowable angular position width of the upstream delivery pole N2 (A) is ± 1.5 °, and the allowable angular position width of the downstream delivery pole S1 (B) is ± 2. 5 °. The allowable angular position width is smaller than the tolerance width at the time of magnetization.

  In this embodiment, paying attention to the magnet roller that is the object of adjustment of the angular position, the method for adjusting the angular position of the magnet roller generally includes the following steps. When generically referring to the upstream and downstream elements described above, the suffixes A and B are omitted. When referring to the left and left elements, the suffixes L and R are omitted. To do.

  (A) A step of arranging at least the developing sleeve unit 5 of the developing device 4 in the adjusting device 200. As described above, the adjustment device 200 includes the drive unit 201 that is connected to the core member 50 of the magnet roller 47 and rotationally drives the magnet roller 47 so that the rotation angle can be detected. The adjustment device 200 includes a magnetic flux sensor 202 that can detect the magnetic flux generated by the magnet roller 47 at a predetermined position in the circumferential direction of the developing sleeve 41.

  (B) A step of detecting the magnetization position reference of the magnetic pole in the circumferential direction of the magnet roller 47. In this embodiment, the magnetization position reference is a reference magnetic pole (N1 (A) or N1 (B)) in which the maximum value of the magnetic flux density in the normal direction is distinguishable from other magnetic poles among the plurality of magnetic poles of the magnet roller 47. The angular position of the magnet roller 47 in the circumferential direction. In particular, in this embodiment, the reference magnetic pole is the development main pole. However, it is not limited to this.

  (C) A step of detecting an angular position of a specific magnetic pole of the magnet roller 47 with respect to a magnetization position reference from information indicating a relationship between the rotation angle of the magnet roller 47 and the magnetic flux density. Information indicating the relationship between the rotation angle of the magnet roller 47 and the magnetic flux density is acquired by detecting the magnetic flux generated by the magnet roller by the magnetic flux sensor 202 while rotating the magnet roller 47 by the drive unit 201. The acquisition of this information may be performed before the step (b), may be performed substantially simultaneously, or may be performed later. As will be described in detail later, in this embodiment, before the step (b), the relationship between the rotation angle and the magnetic flux density over one rotation of the magnet roller 47 is acquired. And the detection of the magnetization position reference | standard in the said (b) process is also performed using this information. In this embodiment, the specific magnetic pole is a delivery pole (N2 (A) or S1 (B)).

  (D) A step of arranging the specific magnetic pole of the magnet roller 47 at a predetermined angular position in the circumferential direction of the developing sleeve 41 by the drive unit 201 according to the detected angular position of the specific magnetic pole with respect to the magnetization position reference. In the present embodiment, the predetermined angular position is set as an angular position with respect to a reference plane (X1 or X2) passing through the rotation center of the developing sleeve 41 and the reference position in the circumferential direction in the circumferential direction of the developing sleeve 41.

  (E) A step of fixing the magnet roller 47 to the developing sleeve 41 so as not to rotate.

  In this embodiment, the two magnet rollers 47A and 47A are the magnet rollers whose angular positions are to be adjusted, and the angles in the circumferential direction of the corresponding developing sleeves 41A and 41B of the two magnet rollers 47A and 47B, respectively. Adjust the position. In this case, after the step (a), the step (b) to the step (e) are performed first for any of the magnet rollers 47A and 47B, or substantially for both the magnet rollers 47A and 47B. Can be performed simultaneously. In this embodiment, the process was performed sequentially from the upstream magnet roller 47A to the downstream magnet roller 47B.

  As described above, in the developing device 4 of the present embodiment, the developing sleeve that includes the magnet rollers 47A and 47B in which the magnetic material is disposed around the core members 50A and 50B and is magnetized to form a plurality of magnetic poles. A plurality of 41A and 41B are arranged in the developer transport direction. Then, the application of the developer onto the developing sleeve 47B disposed on the downstream side in the developer conveyance direction and the regulation of the amount thereof are formed in the gap formed between the adjacent developing sleeves 41A and 41B and the gap. This is done by a magnetic field. In the developing device 4, the angular positions of the developing sleeves 41A and 41B in the circumferential direction of the magnet rollers 47A and 47B are adjusted when the core members 50A and 50B are fixed to the left support member 48L. That is, the core members 50A and 50B of the magnet rollers 47A and 47B are connected to the drive units 201A and 201B that can rotate the driven member at every predetermined step angle as a drive unit that can detect the rotation angle, The rollers 47A and 47B are rotationally driven. At this time, the drive units 201A and 201B rotate and drive the magnet rollers 47A and 47B at every step angle smaller than the width of the angular position allowed to keep the toner application state uniform. Then, the magnetic pole sensors 202A and 202B as magnetic flux detection means for detecting the magnetic flux on the surfaces of the magnet rollers 47A and 47B specify the delivery pole as a specific magnetic pole (search and detection of the angular position with respect to the magnetized position reference). . At this time, the relationship between the rotation angle of the magnet rollers 47A and 47B detected by the magnetic flux sensors 202A and 202B and the magnetic flux density is stored, and the regions where the developing sleeves 41A and 41B are close to each other are calculated based on the relationship. A magnetic pole toward G is specified. Then, the angular position of the specific magnetic pole in the circumferential direction of the corresponding developing sleeve 41A, 41B is adjusted to a desired angular position by rotationally driving the magnet rollers 47A, 47B by the driving units 201A, 201B. In this embodiment, the desired angular position is set as an angular position with respect to predetermined reference planes X1 and X2 that pass through the rotation centers of the developing sleeves 41A and 41B and the reference position in the circumferential direction. The magnet rollers 47A and 47B are fixed to the developing sleeves 41A and 41B so as not to rotate after being stopped at desired angular positions.

  According to the present embodiment, by such an angular position adjustment method, the angle formed by specifying a specific magnetic pole and the maximum position of the magnetic pole with a predetermined reference plane is set to a desired angle with necessary accuracy (for example, ± 1 °). It becomes possible to decide on.

6). Specific Example of Adjustment Procedure Next, an example of a more specific adjustment procedure of the angular position of the magnet roller in the present embodiment will be described with reference to a flowchart.

  Referring to FIG. 7, the angle formed by the reference plane X1 and the maximum position of the transfer pole N2 (A) is 71.5 using the upstream magnet roller 47B that is magnetized and manufactured with the accuracy as described above. A procedure for adjusting to be within a range of ± 1.5 ° will be described.

  First, when the developing sleeve unit 5 is attached to the adjustment device 200 and a start instruction is input from the operation unit 206 of the adjustment device 200 to the CPU 251 of the controller 205, the CPU 251 starts an adjustment procedure (S101).

  Next, the CPU 251 detects the magnetic flux density by the upstream magnetic flux sensor 202A while rotating the upstream magnet roller 47A by 360 ° by the upstream drive unit 201A (S102).

  Then, the CPU 251 stores the relationship between the step angle of the upstream drive unit 201A (that is, the rotation angle of the upstream magnet roller 47A) and the detected value of the magnetic flux density in the normal direction in the memory 252 (S103).

  Next, the CPU 251 determines whether or not there are eight local maximum magnetic flux densities (S104). This is because the upstream magnet roller 47A is an 8-pole magnet roller in this embodiment.

  If it is determined in S104 that “Yes” (the maximum value of the magnetic flux density in the normal direction is eight), then the CPU 251 determines that the maximum value B [N1 (A)] of the magnetic flux density in the normal direction is 110 ± 10 mT. It is determined whether or not a magnetic pole satisfying (100 mT ≦ B [N1 (A)] ≦ 120 mT) is detected. If detected, the magnetic pole is identified as the upstream developing main pole (reference magnetic pole) N1 (A) (S105). In this embodiment, the maximum value of the magnetic flux density in the normal direction of the upstream developing main pole N1 (A) is 110 ± 10 mT including the range of tolerance, and the maximum value of the magnetic flux density in the normal direction in this range is This is because there is no magnetic pole other than the upstream developing main N1 (A). .

  If it is determined as “Yes” (the upstream developing main pole N1 (A) is detected) in S105, the CPU 251 next searches for the upstream delivery pole N2 (A). That is, the CPU 251 determines whether or not the maximum value of the magnetic flux density in the normal direction is detected in the next angle range from the information indicating the relationship between the acquired rotation angle and the magnetic flux density (S106). 74 ± 3 ° (71 ° ≦ ψ ≦ 77) on the side corresponding to the downstream side in the rotation direction of the upstream developing sleeve 41A (+ side: clockwise in FIG. 6) with the upstream developing main pole N1 (A) as a reference. °) angle range. In the present embodiment, the upstream transfer pole (specific magnetic pole) N2 (A) is within this angular range with respect to the upstream development main pole N1 (A) even when the tolerance width at the time of magnetization is taken into consideration. This is because it is magnetized.

  If it is determined as “Yes” (detects the upstream delivery pole N2 (A)) in S106, the CPU 251 then determines the maximum value B [N2 () of the magnetic flux density in the normal direction of the upstream delivery pole N2 (A). A)] is within the standard range (S107). In this embodiment, this standard range is 80 ± 5 mT (75 mT ≦ B [N2 (A)] ≦ 85 mT).

  When determining “Yes” in S107 (the magnetic flux density of the upstream delivery pole N2 (A) is within the standard range), the CPU 251 next adjusts the angular position of the upstream magnet roller 47A by the upstream drive unit 201A. (S108). That is, the CPU 251 calculates an angle δ for shifting the maximum position of the upstream development main pole N1 (A) with reference to the reference plane X1, based on the acquired information indicating the relationship between the rotation angle and the magnetic flux density. This angle δ is calculated from the angle ψ formed by the detected maximum position of the upstream development main pole N1 (A) and the maximum position of the upstream delivery pole N2 (A) by the following equation: δ = 71.5−ψ can do. In order to maintain a good toner application state on the downstream developing sleeve 41B, the angle formed by the upstream transfer pole N2 (A) and the reference plane X1 is 71.5 ± 1.5 ° (clockwise in FIG. 6). This is because it is required to be within the range. Then, the CPU 251 rotates the upstream magnet roller 47A by the calculated shift amount and then stops it.

  Next, the fixing member 49A is fixed to the left supporting member 48L, and the upstream magnet roller 47A is fixed to the upstream developing sleeve 41A so as not to rotate (S109).

  Thus, the procedure for adjusting the angular position of the upstream magnet roller 47A is completed (S110). In addition, after stopping the rotation of the upstream magnet roller 47A in S108, it may be displayed on the operation unit 206 that the angular position adjustment is completed. In this case, the upstream magnet roller 47A is fixed by the fixing member 49A according to the display.

  On the other hand, if “No” is determined in S104, S105, S106, and S107, the CPU 251 determines an error (S111). Next, the CPU 251 determines whether or not the number of errors so far is 0 (S112). If the number of errors up to that point is zero, the CPU 251 returns to S102 and starts remeasurement. On the other hand, when the number of times is not 0, the CPU 251 causes the operation unit 206 to display a warning display such as displaying the developing sleeve unit 5 so as to be removed from the adjusting device 200 and sent to the reexamination process of the upstream magnet roller 47A. (S113).

  By the above procedure, the maximum position of the upstream delivery pole N2 (A) with respect to the reference plane X1 is 71.5 in consideration of the angle adjustment error ± 0.5 ° and the rotation error ± 0.5 ° associated with screwing. It can be adjusted and fixed within a range of ± 1 ° (clockwise in FIG. 6).

  Next, using the downstream magnet roller 47B that is magnetized and manufactured with the accuracy as described above, the angle formed by the reference plane X2 and the maximum position of the transfer pole S1 (B) is 89 ± 2.5 °. A procedure for adjusting to be within the range will be described.

  In this embodiment, the adjustment procedure of the angular position of the downstream magnet roller 47B is replaced with the adjustment procedure of the angular position of the upstream magnet roller 47A described with reference to FIG. It is the same. Therefore, hereinafter, the difference from the procedure for adjusting the angular position of the upstream magnet roller 47A will be particularly described with reference to FIG.

  In this embodiment, when the procedure for adjusting the angular position of the upstream magnet roller 47A is completed according to the flowchart of FIG. 7, the CPU 251 continues the procedure to the step corresponding to S101, and determines the angular position of the downstream magnet roller 47B. Start the adjustment procedure.

  In S104, it is determined whether there are five local maximum magnetic flux densities. This is because the downstream magnet roller 47B is a five-magnet magnet roller.

  In S105, the downstream development main pole N1 (B) where the maximum value of the magnetic flux density in the normal direction does not intersect with the other four poles including the tolerance range is detected.

  In S106, 86 ± 3 ° (83 °) on the side corresponding to the upstream side in the rotational direction of the downstream side developing sleeve 41B (− side: counterclockwise in FIG. 6) with the downstream side developing main pole N1 (B) as a reference. The downstream transfer pole (specific magnetic pole) S1 (B) is detected in an angle range of ≦ φ ≦ 89 °.

  In S107, it is determined whether or not the maximum value of the magnetic flux density in the normal direction of the downstream delivery pole S1 (B) is within the standard range.

  In S108, based on the information indicating the relationship between the rotation angle and the magnetic flux density stored in the memory 252, the angle ε for shifting the maximum position of the downstream development main pole N1 (B) with reference to the reference plane X2. calculate. This angle ε is calculated from the angle φ formed by the detected maximum position of the downstream development main pole N1 (B) and the maximum position of the downstream transfer pole S1 (B) by the following equation: ε = φ−89. Can do. In order to maintain a good toner application state on the downstream developing sleeve 41B, the angle formed by the downstream delivery pole S1 (B) and the reference plane X2 is in the range of 89 ± 2.5 ° (counterclockwise in FIG. 6). This is because it is required to be within. Then, the downstream magnet roller 47B is rotated by the calculated shift amount, and then stopped.

  In S109, the fixing member 49B is fixed to the left support member 48L, and the downstream magnet roller 47A is fixed to the downstream developing sleeve 41B so as not to rotate.

  The developing sleeve unit 5 whose angle has been adjusted is removed from the adjusting device 200.

  Through the above procedure, the maximum position of the downstream delivery pole S1 (B) with respect to the reference plane X2 can be adjusted and fixed within a range of 89 ± 1 ° (counterclockwise in FIG. 6).

  As described above, according to the present embodiment, the angle formed by the specific magnetic pole of the magnet roller with the predetermined reference plane can be positioned with high accuracy such as ± 1 ° around the desired angle. As a result, it becomes possible to stably apply the toner to the downstream developing sleeve and to regulate the amount thereof.

Example 2
Next, another embodiment of the present invention will be described. The basic configuration and operation of the image forming apparatus and the developing device in this embodiment and the outline of the method for adjusting the angular position of the magnet roller are the same as those in the first embodiment. Therefore, the same reference numerals are given to elements having the same configuration and function as those of the first embodiment, or the detailed description thereof will be omitted.

  Similar to the first embodiment, in this embodiment, a case where the angular positions of the upstream and downstream transfer poles that affect the uniformity of the toner application state on the downstream developing sleeve will be described. In this embodiment, the upstream and downstream magnet rollers 47A and 47B do not have magnetic poles that do not intersect with other magnetic poles, including the range of tolerances, in which the maximum value of the magnetic flux density in the normal direction is included. That is, each magnetic pole intersects with at least one other magnetic pole when the maximum value of the magnetic flux density in the normal direction also takes into account the tolerance range. Therefore, it is difficult to specify a certain magnetic pole with the maximum value of the magnetic flux density in the normal direction, and it is difficult to distinguish the magnetic pole from other magnetic poles and use it as a magnetization position reference. In this embodiment, a method for determining the magnetic pole to be noted and the angular position with high accuracy, for example, ± 1 ° in such a case will be described.

  FIG. 8 is a schematic diagram illustrating a configuration of a main part of the adjusting device 200 for adjusting the angular position of the magnet roller in the present embodiment. Further, FIG. 9 is a diagram illustrating an essential part of the adjusting device 200 in the direction orthogonal to the rotation axis of the upstream and downstream developing sleeves 41A and 41B for explaining the procedure for adjusting the angular position of the magnet roller in this embodiment. It is typical sectional drawing.

  In this embodiment, D cut processing is applied to the left end portions 54A and 54B of the core members 50A and 50B of the upstream and downstream magnet rollers 47A and 47B to form D cut surfaces 55A and 55B. Yes. Further, the adjusting device 200 receives the D-cut surfaces 55A and 55B of the upstream and downstream magnet rollers 47A and 47B by connecting portions (not shown) of the upstream and downstream drive units 201A and 201B, respectively. In this embodiment, the adjusting device 200 initializes an angular position (initialization function) that makes the normal directions of the D-cut surfaces 55A and 55B substantially coincide with the reference planes X1 and X2, that is, a home position ( H. P) has a function of detecting.

  More specifically, in this embodiment, the magnetic poles of the upstream and downstream magnet rollers 47A and 47B are magnetized with an accuracy of ± 3 ° with respect to the normal direction of the D-cut surfaces 55A and 55B, respectively. Therefore, the upstream delivery pole N2 (A) is magnetized with an accuracy of 71.5 ± 3 ° (FIG. 9 clockwise: angle ξ) with respect to the normal direction of the D-cut surface 55A. Further, the downstream delivery pole S1 (B) is magnetized with an accuracy of 89 ± 3 ° (counterclockwise in FIG. 9: angle ω) with respect to the normal direction of the D-cut surface 55B.

  Further, in the present embodiment, the upstream and downstream drive units 201A and 201B having the connecting portions that receive the D-cut surfaces 55A and 55B have home positions. The CPU 251 of the controller 205 detects the home positions of the upstream and downstream drive units 201A and 201B via the encoders 207A and 207B. This home position is set so that the position of the connecting portion corresponding to the normal direction of the D-cut surfaces 55A and 55B substantially coincides with the reference planes X1 and X2. As a result, the CPU 251 aligns the upstream and downstream drive units 201A and 201 with the home position, so that the normal directions of the D-cut surfaces 55A and 55B are approximately equal to the reference planes X1 and X2, respectively. Can be initialized (initialized).

  Here, in this embodiment, the angle formed between the normal direction of each of the D-cut surfaces 55A and 55B received by the connecting portion on the adjustment device 200 side and the reference planes X1 and X2 is within a range of ± 0.5 °. Can be controlled within. The upstream and downstream drive units 201A and 201B can rotate and drive the upstream and downstream magnet rollers 47A and 47B with an accuracy of 0.5 ° / step, respectively.

  In this embodiment, paying attention to the magnet roller that is the object of adjustment of the angular position, the method for adjusting the angular position of the magnet roller generally includes the steps (a) to (e) described in the first embodiment.

  However, in this embodiment, the magnetization position reference in step (b) described in Embodiment 1 is the angular position of the reference shape formed on the core material 50 of the magnet roller 47 in the circumferential direction of the magnet roller 47. . In particular, in this embodiment, the reference shape is a D-cut surface 55 (more specifically, the normal direction) formed on the core member 50 of the magnet roller 47. However, it is not limited to this. Any shape can be used as long as the reference position at the time of magnetization in the circumferential direction of the magnet roller 47 can be transmitted to the adjusting device 200 side. For example, it may be a stamp or notch formed on the core material 50 of the magnet roller 47.

  In the present embodiment, information indicating the relationship between the rotation angle of the magnet roller 47 and the magnetic flux density used to detect the angular position of the specific magnetic pole with respect to the magnetization position reference in the step (c) described in the first embodiment. Is obtained after the step (b) described in the first embodiment. In this embodiment, the relationship between the rotation angle of the magnet roller 47 and the magnetic flux density is acquired based on the magnetization position reference detected in the step (b), and the magnetization position of a specific magnetic pole is obtained from the relationship. An angular position relative to the reference is detected.

  Next, an example of a more specific procedure for adjusting the angular position of the magnet roller in this embodiment will be described with reference to a flowchart.

  With reference to FIG. 10, the procedure for adjusting the angular position of the upstream delivery pole N2 (A) of the upstream magnet roller 47A will be described.

  First, when the developing sleeve unit 5 is attached to the adjustment device 200 and a start instruction is input from the operation unit 206 of the adjustment device 200 to the CPU 251 of the controller 205, the CPU 251 starts an adjustment procedure (S201).

  Next, the CPU 251 detects the home position of the upstream drive unit 201A, thereby causing the normal direction of the D-cut surface 55A and the reference plane X1 to be aligned (S202).

  Next, the CPU 251 detects the magnetic flux density by the upstream magnetic flux sensor 202A while rotating the upstream magnet roller 47A by the upstream drive unit 201A. At this time, the CPU 251 stores the relationship between the step angle of the upstream drive unit 201A (that is, the rotation angle of the upstream magnet roller 47A) and the detected value of the magnetic flux density in the normal direction in the memory 252 (S203). .

  Then, the CPU 251 searches for the upstream delivery pole N2 (A) (S204). That is, the CPU 251 determines whether or not there is a local maximum magnetic flux density value in the next angle range from the acquired information indicating the relationship between the rotation angle and the magnetic flux density. 71.5 ± 4 ° (67.5 ° ≦ ξ ≦ 75.5 °) on the side corresponding to the downstream side in the rotation direction of the upstream developing sleeve 41A (+ side: clockwise in FIG. 9) with respect to the home position. ) Angle range. In this embodiment, even if the error range (± 4 °) is taken into consideration, the upstream delivery pole N2 (A) is magnetized in this angular range with respect to the normal direction of the D-cut surface 55A. . This error range (± 4 °) includes the tolerance width (± 3 °) during magnetization, the error width (± 0.5 °) between the normal direction of the D-cut surface and the reference plane X1, and the home. The angle adjustment error width (± 0.5 °) at the time of initialization to the position is combined.

  If it is determined as “Yes” in S204 (a magnetic pole is detected at a predetermined angular position), then the CPU 251 determines that the maximum value of the magnetic flux density in the normal direction of the magnetic pole is the modulus of the upstream delivery pole N2 (A). It is determined whether or not the maximum value B [N2 (A)] of the magnetic flux density in the linear direction is within a standard range (S205). In this embodiment, this standard range is 80 ± 5 mT (75 mT ≦ B [N2 (A)] ≦ 85 mT).

  If it is determined as “Yes” in S205 (the magnetic flux density of the detected magnetic pole is within the standard range), the CPU 251 then identifies the magnetic pole as the upstream delivery pole N2 (A) (S206).

  Then, the CPU 251 adjusts the angular position of the upstream magnet roller 47A by the upstream drive unit 201A (S207). That is, the CPU 251 sets the normal direction of the D-cut surface 55A so that the angle formed by the maximum position of the upstream delivery pole N2 (A) and the reference plane X1 is 71.5 ° (clockwise in FIG. 9). Shift with respect to the reference plane X1. The shift amount can be obtained from the angle formed by the detected normal direction of the D-cut surface 55A and the upstream delivery pole N2 (A) based on the information indicating the relationship between the acquired rotation angle and the magnetic flux density. The CPU 251 rotates the upstream magnet roller 47A in this way and then stops it.

  Next, the fixing member 49A is fixed to the left support member 48L, and the upstream magnet roller 47A is fixed to the upstream developing sleeve 41A so as not to rotate (S208).

  Thus, the procedure for adjusting the angular position of the upstream magnet roller 47A is completed (S209). In addition, after stopping the rotation of the upstream magnet roller 47A in S207, it may be displayed on the operation unit 206 that the adjustment of the angular position is completed. In this case, the upstream magnet roller 47A is fixed by the fixing member 49A according to the display.

  On the other hand, if “No” is determined in S204 and S205, the CPU 251 determines an error (S210). Next, the CPU 251 determines whether or not the number of errors so far is 0 (S211). If the number of errors up to that point is zero, the CPU 251 returns to S202 and starts remeasurement. On the other hand, when the number of times is not 0, the CPU 251 causes the operation unit 206 to display a warning display such as displaying the developing sleeve unit 5 so as to be removed from the adjusting device 200 and sent to the reexamination process of the upstream magnet roller 47A. (S113).

  By the above procedure, the maximum position of the upstream delivery pole N2 (A) with respect to the reference plane X1 is 71.5 in consideration of the angle adjustment error ± 0.5 ° and the rotation error ± 0.5 ° associated with screwing. It can be adjusted and fixed within a range of ± 1 ° (clockwise in FIG. 9).

  Next, a procedure for adjusting the angular position of the downstream delivery pole S1 (B) of the downstream magnet roller 47B will be described.

  In this embodiment, the adjustment procedure of the angular position of the downstream magnet roller 47B is replaced with the adjustment procedure of the angular position of the upstream magnet roller 47A described with reference to FIG. It is the same. Therefore, hereinafter, the difference from the procedure for adjusting the angular position of the upstream magnet roller 47A will be particularly described with reference to FIG.

  In this embodiment, when the procedure for adjusting the angular position of the upstream magnet roller 47A is completed according to the flowchart of FIG. 10, the CPU 251 continues the procedure to the step corresponding to S201, and determines the angular position of the downstream magnet roller 47B. Start the adjustment procedure.

  In S202, the normal direction of the D cut surface 55B formed on the core material 50B of the downstream magnet roller 47B is initialized so as to substantially coincide with the reference plane X2.

  In S203 and S204, the magnetic pole having the maximum value of the magnetic flux density in the normal direction in the next angular range is detected by rotational driving of the downstream magnet roller 47B and detection of the magnetic flux density. The angle range is 89 ± 4 ° (85 ° ≦ ω ≦ 93 °) from the reference plane X2 to the side corresponding to the upstream side in the rotation direction of the downstream developing sleeve 41B (−side: counterclockwise in FIG. 9).

  In S205, it is determined whether or not the detected maximum value of the magnetic flux density in the normal direction of the magnetic pole is within the standard range of the downstream delivery pole S1 (B).

  In S206, the downstream delivery pole S1 (B) is specified.

  In S207, the downstream magnet roller 47B is rotated so that the angle between the maximum position of the downstream delivery pole S1 (B) and the reference plane X1 is 89 ° (counterclockwise in FIG. 9), and then stopped. Let

  In S208, the fixing member 49B is fixed to the left support member 48L, and the downstream magnet roller 47B is fixed to the downstream developing sleeve 41B so as not to rotate.

  The developing sleeve unit 5 whose angle has been adjusted is removed from the adjusting device 200. Thereafter, the CPU 251 may return the upstream drive unit 201 to the home position.

  With the above procedure, the maximum position of the downstream delivery pole S1 (B) with respect to the reference plane X2 can be adjusted and fixed in the range of 89 ± 1 ° (counterclockwise in FIG. 9).

  As described above, according to the present embodiment, the core member is provided with the reference surface (D-cut surface) as the magnetization position reference, and the reference surface and the home position of the adjusting device are associated with each other, so Identify. Further, the adjusting device is provided with a magnetic flux sensor and a drive unit that can be driven with a step angle smaller than the accuracy required for the angular position of the magnetic pole. This makes it possible to adjust the angular position of the magnetic pole that needs to be adjusted with high accuracy, for example, ± 1 ° around the desired angle. As a result, it becomes possible to stably apply the toner to the downstream developing sleeve and to regulate the amount thereof.

Others While the present invention has been described with reference to specific embodiments, the present invention is not limited to the above-described embodiments.

  For example, in the above-described embodiment, attention is paid to the adjustment of the angular position of the magnetic pole adjacent to the transfer portion, which is considered to be particularly severe in setting the angular position of the magnetic pole. The same adjustment method as that of the above-described embodiment may be applied to the specific magnetic pole.

  Further, the same method as in the second embodiment can be applied to a magnet roller having a magnetic pole in which the maximum value of the magnetic flux density in the normal direction does not overlap with other magnetic poles including a tolerance range.

  Further, the magnetization position reference is not limited to the predetermined magnetic pole or the predetermined reference shape in the above-described embodiment, and for example, a mark provided by an arbitrary method such as printing or sticking on the core material of the magnet roller. There may be. In addition, a separate member having a reference shape and a mark that serves as a reference for the magnetizing position is fixed to the end of the core member of the magnet roller by any fixing means such as engagement, fitting, adhesion, etc. You may attach to a roller. Also in this case, for example, as in the second embodiment, by associating the magnetization position reference with the home position of the adjusting device, the angular position of the specific magnetic pole of the magnet roller with respect to the magnetization position reference can be detected.

  In the above-described embodiment, the developing sleeve unit is arranged in the adjusting device, and the angular position of the magnet roller is adjusted. However, as long as it has a magnet roller and a corresponding developing sleeve, the unit arranged in the adjusting device is not limited to the developing sleeve unit as in the above-described embodiment. For example, a unit in which a substantially completed developing device is disposed in the adjusting device may be used.

  In the above-described embodiments, the method for adjusting the angular position of the magnet roller has been described as being performed when the developing device is manufactured. However, the present invention is not limited to this. The angular position of the magnet roller according to the invention for adjusting or resetting the angular position of the magnet roller in a process for repair or reuse in a developing device after completion, for example a developing device in use or after use An adjustment method may be applied.

  In the above-described embodiment, the adjustment of the position of the magnetic pole adjacent to the gap between the two developer carriers in the developing device having a plurality of developer carriers has been described. However, for example, the present invention can be applied to adjust the angular position of the magnet roller in a developing device having only one developer carrier, and the angular position of the magnet roller in the circumferential direction of the developing sleeve can be more accurately determined. It becomes possible to adjust.

  In the above-described embodiment, the developing device using the one-component magnetic developer as the developer has been described. However, the present invention is not limited to this, and is also applicable to adjusting the angular position of a magnet roller in a developing device using a two-component developer having non-magnetic toner particles (toner) and magnetic carrier particles (carrier). And the same effect can be obtained.

1 Photosensitive drum (image carrier)
4 Developing device 5 Developing sleeve unit 41A, 41B Developing sleeve (developer carrier)
47A, 47B Magnet roller 48L, 48R Support member 49A, 49B Fixing member (fixing means)
50A, 50B Core material 100 Image forming apparatus 200 Adjustment apparatus 201A, 201B Drive unit (drive means)
202A, 202B Magnetic flux sensor (magnetic flux detection means)

Claims (12)

A developer carrier for carrying and transporting the developer, and a magnet disposed in a hollow portion of the developer carrier including a core material and a plurality of magnetic poles disposed around the rotation center axis of the core material In the method for adjusting the angular position of the magnet roller in the developing device having a unit comprising a roller,
A drive means connected to the core material of the magnet roller for rotationally driving the magnet roller and capable of detecting a rotation angle, and a magnetic flux generated by the magnet roller at a predetermined position in the circumferential direction of the developer carrier can be detected. A step of disposing at least the unit of the developing device in an adjusting device having a magnetic flux detecting means;
Detecting a magnetization position reference of the magnetic pole in the circumferential direction of the magnet roller;
From the information indicating the relationship between the rotation angle of the magnet roller and the magnetic flux density obtained by detecting the magnetic flux generated by the magnet roller by the magnetic flux detection means while rotating the magnet roller by the drive means, Detecting an angular position of the specific magnetic pole of the magnet roller with respect to the magnetization position reference;
According to the detected angular position of the specific magnetic pole with respect to the magnetization position reference, the specific magnetic pole of the magnet roller is arranged at a predetermined angular position in the circumferential direction of the developer carrier by the driving means. Process,
Fixing the magnet roller with respect to the developer carrying member in a non-rotatable manner;
An angular position adjustment method comprising:   The magnetization position reference is an angular position in the circumferential direction of the magnet roller of a reference magnetic pole in which the maximum value of the magnetic flux density in the normal direction among the plurality of magnetic poles of the magnet roller is distinguishable from other magnetic poles. The angular position adjustment method according to claim 1, wherein   2. The angular position adjusting method according to claim 1, wherein the magnetization position reference is an angular position in a circumferential direction of the magnet roller of a reference shape formed on the core material of the magnet roller. Two developer carrying bodies arranged close to each other for carrying and transporting the developer, and a plurality of magnetic poles arranged respectively around a core material and a rotation center axis of the core material In the method of adjusting the angular position of a magnet roller in a developing device having a unit comprising two magnet rollers arranged in the hollow portion of the corresponding developer carrier among the two developer carriers,
A driving means connected to the core material of the target magnet roller of at least the two magnet rollers and rotationally driving the magnet roller; and the target of at least the two developer carriers. A magnetic flux detecting means capable of detecting a magnetic flux generated by the target magnet roller at a predetermined position in the circumferential direction of the developer carrier corresponding to the magnet roller, and at least the unit of the developing device. A step of arranging
Detecting a magnetization position reference of a magnetic pole in a circumferential direction of the target magnet roller of the two magnet rollers;
The rotation angle and magnetic flux density of the target magnet roller obtained by detecting the magnetic flux generated by the target magnet roller by the magnetic flux detection means while rotating the target magnet roller by the driving means. Detecting the angular position of the specific magnetic pole adjacent to the proximity of the two developer carriers among the magnetic poles of the target magnet roller from the information indicating the relationship with respect to the magnetization position reference;
According to the detected angular position of the specific magnetic pole with respect to the magnetization position reference, the driving means causes the specific magnetic pole of the target magnet roller to be moved in a predetermined direction in the circumferential direction of the corresponding developer carrier. Arranging at an angular position;
Fixing the target magnet roller to the corresponding developer carrying member in a non-rotatable manner;
An angular position adjustment method comprising:   The magnetization position reference is a reference magnetic pole in the circumferential direction of the target magnet roller, in which the maximum value of the magnetic flux density in the normal direction is distinguishable from other magnetic poles among the plurality of magnetic poles of the target magnet roller. The angular position adjustment method according to claim 4, wherein the angular position adjustment method is an angular position.   The said magnetization position reference | standard is an angular position in the circumferential direction of the said magnet roller made into the object of the reference | standard shape formed in the said core material of the said magnet roller made into the object. Angular position adjustment method.   7. The angular position in the circumferential direction of the developer carrier corresponding to each of the two magnet rollers is adjusted by using the two magnet rollers as the target magnet rollers, respectively. The angular position adjustment method as described in any one of Claims.   The two developer carriers are respectively arranged to face an image carrier on which an electrostatic image is formed, and are driven to rotate in the same direction. Of the two developer carriers, The upstream developer carrier in the developer transport direction by the two developer carriers at the portion facing the image carrier is the downstream side in the same direction at the proximity of the two developer carriers. The angular position adjusting method according to any one of claims 4 to 7, wherein the developer carried on the developer carrying body is regulated.   The driving means is capable of rotating the magnet roller connected thereto for each rotation angle smaller than an allowable range of an angular position of the specific magnetic pole in the circumferential direction of the developer carrier. The angular position adjustment method according to any one of claims 1 to 8.   The angular position adjusting method according to claim 1, wherein the developing device uses a one-component magnetic developer as the developer.   A method for manufacturing a developing device, comprising adjusting an angular position in a circumferential direction of a developer carrier corresponding to a magnet roller by the angular position adjusting method according to claim 1.   11. A developing device, wherein an angular position in a circumferential direction of a developer carrying member corresponding to a magnet roller is adjusted by the angular position adjusting method according to any one of claims 1 to 10.

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