Method for fixing regulating blade, developing device, developer carrying member and magnet

Abstract

The present invention provides a method for fixing a regulating blade, a developing device, a developer carrying member, and a magnet. A target value of a gap between the developer carrying member supported by the developing frame member and the regulating blade fixed to the developing frame member is determined based on input information regarding a local maximum peak value of magnetic flux density of a predetermined magnetic pole, among a plurality of magnetic poles, which is positioned closest to the regulating blade when the regulating blade is fixed to the developing frame member. The plurality of magnetic poles are included in a magnet fixedly positioned inside the developer carrying member and configured to generate a magnetic field for causing the developer to be carried by the developer carrying member.

Description

[0001] This application is a divisional application of the invention patent application with application number 201910100732.0 filed on January 31, 2019, and invention name “Method for fixing regulating blades, developing device, developer carrying component and magnet”. Technical Field

[0002] Aspects of the present invention generally relate to a fixing method of a regulating blade, a developing device, a developer carrying member, and a magnet. Background Art

[0003] The developing device includes a regulating blade serving as a developer regulating member that regulates the amount of developer carried on the surface of a developer carrying member (developer coating amount). The developer carrying member carries a developer containing a toner and a carrier to develop an electrostatic latent image formed on an image carrying member. The regulating blade is positioned relative to the developer carrying member in the longitudinal direction of the developer carrying member, with a predetermined gap (hereinafter referred to as an "SB gap") between the regulating blade and the developer carrying member. The SB gap refers to the shortest distance between the developer carrying member supported by a developing frame member and the regulating blade fixed to the developing frame member. Adjusting the size of the SB gap results in adjusting the developer conveyed to the developing area of ​​the developer carrying member facing the image carrying member.

[0004] In the developing device discussed in Japanese Patent Application Laid-Open No. 2012-145937, a magnet having multiple magnetic poles is fixedly positioned inside a developer carrying member, and an S2 pole (regulation pole) and an N1 pole of opposite polarity are positioned near a regulating blade. The regulating pole has a local maximum peak value of magnetic flux density at a position located upstream of the regulating blade with respect to the rotational direction of the developer carrying member and closest to the regulating blade.

[0005] The local maximum peak value of the magnetic flux density of the regulating pole included in each magnet may vary between individual magnets.

[0006] For example, when the local maximum peak value of the magnetic flux density of the regulating pole is large, the magnitude of the magnetic force acting on the carrier contained in the developer in contact with the upstream side of the regulating blade relative to the rotational direction of the developer carrying member tends to increase. Therefore, when the local maximum peak value of the magnetic flux density of the regulating pole is greater than a predetermined value, the amount of developer applied when the SB gap is set to the same value becomes greater than when the local maximum peak value of the magnetic flux density of the regulating pole is the predetermined value. On the other hand, when the local maximum peak value of the magnetic flux density of the regulating pole is small, the magnitude of the magnetic force acting on the carrier contained in the developer in contact with the upstream side of the regulating blade relative to the rotational direction of the developer carrying member tends to decrease. Therefore, when the local maximum peak value of the magnetic flux density of the regulating pole is less than a predetermined value, the amount of developer applied when the SB gap is set to the same value becomes smaller than when the local maximum peak value of the magnetic flux density of the regulating pole is the predetermined value.

[0007] In this way, when the size of the SB gap is set at the same value without considering the local maximum peak value of the magnetic flux density of the regulating pole, the developer coating amount may change for each individual developing device due to the change in the local maximum peak value of the magnetic flux density of the regulating pole for each individual magnet.

[0008] Furthermore, the local maximum peak position of the magnetic flux density of the regulating pole included in each magnet may vary for each individual magnet. Similarly, if the SB gap is set to the same value without considering the local maximum peak position of the magnetic flux density of the regulating pole, the developer coating amount may vary for each individual developing device due to the variation in the local maximum peak position of the magnetic flux density of the regulating pole for each individual magnet. Summary of the Invention

[0009] The first aspect of the present invention is directed to preventing or reducing variations in developer coating amounts for individual developing devices by adjusting the size of the SB gap in consideration of a local maximum peak value of magnetic flux density of a regulating pole included in a magnet.

[0010] A first aspect of the present invention provides a method for fixing a regulating blade, for fixing a regulating blade to a developing frame member, the regulating blade being positioned opposite to a developer carrying member and being configured to regulate the amount of developer carried by the developer carrying member, the developer carrying member being supported by the developing frame member and being configured to carry the developer to develop an electrostatic latent image formed on the image carrying member, the fixing method comprising the following steps: a determining step of determining a target value of a gap between the developer carrying member supported by the developing frame member and the regulating blade fixed to the developing frame member based on input information about a local maximum peak value of a magnetic flux density of a predetermined magnetic pole, among a plurality of magnetic poles, which is positioned closest to the regulating blade when the regulating blade is fixed to the developing frame member, the plurality of magnetic poles being included in a magnet fixedly positioned inside the developer carrying member and configured to generate a magnetic field for causing the developer to be carried by the developer carrying member; and a fixing step of fixing the regulating blade to the developing frame member so that the gap is set at the target value of the gap determined in the determining step in the longitudinal direction of the developer carrying member.

[0011] The first aspect of the present invention also provides a fixing method for a regulating blade, for fixing a regulating blade to a developing frame member, the regulating blade being positioned opposite to a developer carrying member and being configured to regulate the amount of developer carried by the developer carrying member, the developer carrying member being supported by the developing frame member and being configured to carry the developer to develop an electrostatic latent image formed on an image carrying member, the fixing method comprising the steps of: a determining step, based on input information regarding a predetermined magnetic pole, among a plurality of magnetic poles, which is positioned closest to the regulating blade when the regulating blade is fixed to the developing frame member determining an upper limit value and a lower limit value of a gap between the developer carrying member supported by the developing frame member and the regulating blade fixed to the developing frame member based on information of a local maximum peak value of the magnetic flux density, wherein the plurality of magnetic poles are included in a magnet fixedly positioned inside the developer carrying member and configured to generate a magnetic field for causing the developer to be carried by the developer carrying member; and a fixing step of fixing the regulating blade to the developing frame member so that the gap is set in the longitudinal direction of the developer carrying member between the upper limit value and the lower limit value of the gap determined in the determining step.

[0012] The first aspect of the present invention also provides a developing device, the developing device comprising: a developing frame member; a developer carrying member supported by the developing frame member and configured to carry a developer to develop an electrostatic latent image formed on the image carrying member; a magnet fixedly positioned inside the developer carrying member, having a plurality of magnetic poles, and configured to generate a magnetic field for causing the developer to be carried by the developer carrying member; a regulating blade fixed to the developing frame member, positioned opposite to the developer carrying member, and configured to regulate the developer carried by the developer carrying member and a two-dimensional bar code in which information about a local maximum peak value of the magnetic flux density of a predetermined magnetic pole among the multiple magnetic poles, which is positioned closest to the regulating blade when the regulating blade is fixed to the developing frame member, is recorded, wherein the regulating blade is fixed to the developing frame member so that a gap between the developer carrying member supported by the developing frame member and the regulating blade fixed to the developing frame member is set in the longitudinal direction of the developer carrying member at a target value of the gap corresponding to the local maximum peak value of the magnetic flux density of the predetermined magnetic pole.

[0013] The first aspect of the present invention also provides a developer carrying member, which is supported by a developing frame member and is constructed to carry a developer to develop an electrostatic latent image formed on the image carrying member, the developer carrying member including: a magnet, which is fixedly positioned inside the developer carrying member, has multiple magnetic poles, and is constructed to generate a magnetic field for causing the developer to be carried by the developer carrying member; and a two-dimensional bar code, in which information about the local maximum peak of the magnetic flux density of a predetermined magnetic pole among the multiple magnetic poles, which is positioned closest to the regulating blade when the regulating blade is fixed to the developing frame member, is recorded, and the regulating blade is fixed to the developing frame member, positioned relative to the developer carrying member, and is constructed to adjust the amount of the developer carried by the developer carrying member.

[0014] The first aspect of the present invention also provides a magnet, which is fixedly positioned inside a developer carrying member and is constructed to generate a magnetic field for causing the developer to be carried by the developer carrying member, the developer carrying member being supported by a developing frame member and being constructed to carry the developer to develop the electrostatic latent image formed on the image carrying member, the magnet comprising: a plurality of magnetic poles; and a two-dimensional bar code, in which information about the local maximum peak value of the magnetic flux density of a predetermined magnetic pole among the plurality of magnetic poles, which is positioned closest to the regulating blade when the regulating blade is fixed to the developing frame member, is recorded, the regulating blade being fixed to the developing frame member, positioned relative to the developer carrying member, and being constructed to adjust the amount of the developer carried by the developer carrying member.

[0015] A second aspect of the present invention is directed to preventing or reducing variations in developer coating amounts for individual developing devices by adjusting the size of the SB gap in consideration of the local maximum peak position of the magnetic flux density of a regulating pole included in the magnet.

[0016] A second aspect of the present invention provides a method for fixing a regulating blade, for fixing a regulating blade to a developing frame member, the regulating blade being positioned opposite to a developer carrying member and being configured to regulate the amount of developer carried by the developer carrying member, the developer carrying member being supported by the developing frame member and being configured to carry the developer to develop an electrostatic latent image formed on the image carrying member, the fixing method comprising the following steps: a determining step of determining a target value of a gap between the developer carrying member supported by the developing frame member and the regulating blade fixed to the developing frame member based on input information about a local maximum peak position of a magnetic flux density of a predetermined magnetic pole, among a plurality of magnetic poles, which is positioned closest to the regulating blade when the regulating blade is fixed to the developing frame member, the plurality of magnetic poles being included in a magnet fixedly positioned inside the developer carrying member and configured to generate a magnetic field for causing the developer to be carried by the developer carrying member; and a fixing step of fixing the regulating blade to the developing frame member so that the gap is set at the target value of the gap determined in the determining step in the longitudinal direction of the developer carrying member.

[0017] A second aspect of the present invention further provides a method for fixing a regulating blade, for fixing a regulating blade to a developing frame member, the regulating blade being positioned opposite to a developer carrying member and being configured to regulate the amount of developer carried by the developer carrying member, the developer carrying member being supported by the developing frame member and being configured to carry the developer to develop an electrostatic latent image formed on an image carrying member, the fixing method comprising: a step of determining, based on an input of a magnetic flux of a predetermined magnetic pole among a plurality of magnetic poles, which is positioned closest to the regulating blade when the regulating blade is fixed to the developing frame member information on the position of a local maximum peak of density, determining the upper limit value and the lower limit value of the gap between the developer carrying member supported by the developing frame member and the regulating blade fixed to the developing frame member, the plurality of magnetic poles being included in a magnet fixedly positioned inside the developer carrying member and configured to generate a magnetic field for causing the developer to be carried by the developer carrying member; and a fixing step of fixing the regulating blade to the developing frame member so that the gap is set in the longitudinal direction of the developer carrying member between the upper limit value and the lower limit value of the gap determined in the determining step.

[0018] The second aspect of the present invention also provides a developing device, which includes: a developing frame member; a developer carrying member, which is supported by the developing frame member and is configured to carry a developer to develop an electrostatic latent image formed on the image carrying member; a magnet, which is fixedly positioned inside the developer carrying member, has a plurality of magnetic poles, and is configured to generate a magnetic field for causing the developer to be carried by the developer carrying member; and a regulating blade, which is fixed to the developing frame member, is positioned opposite to the developer carrying member, and is configured to regulate the developer carried by the developer carrying member. and a two-dimensional bar code in which information about a local maximum peak position of the magnetic flux density of a predetermined magnetic pole among the multiple magnetic poles that is positioned closest to the regulating blade when the regulating blade is fixed to the developing frame member is recorded, wherein the regulating blade is fixed to the developing frame member so that a gap between the developer carrying member supported by the developing frame member and the regulating blade fixed to the developing frame member is set in the longitudinal direction of the developer carrying member at a target value of the gap corresponding to the local maximum peak position of the magnetic flux density of the predetermined magnetic pole.

[0019] The second aspect of the present invention also provides a developer carrying member, which is supported by a developing frame member and is constructed to carry a developer to develop an electrostatic latent image formed on the image carrying member, the developer carrying member including: a magnet, which is fixedly positioned inside the developer carrying member, has multiple magnetic poles, and is constructed to generate a magnetic field for causing the developer to be carried by the developer carrying member; and a two-dimensional bar code, in which information about the local maximum peak position of the magnetic flux density of a predetermined magnetic pole among the multiple magnetic poles, which is positioned closest to the regulating blade when the regulating blade is fixed to the developing frame member, is recorded, the regulating blade is fixed to the developing frame member, is positioned relative to the developer carrying member, and is constructed to adjust the amount of the developer carried by the developer carrying member.

[0020] The second aspect of the present invention also provides a magnet, which is fixedly positioned inside a developer carrying member and is constructed to generate a magnetic field for causing the developer to be carried by the developer carrying member, the developer carrying member being supported by a developing frame member and being constructed to carry the developer to develop the electrostatic latent image formed on the image carrying member, the magnet comprising: a plurality of magnetic poles; and a two-dimensional bar code, in which information about the local maximum peak position of the magnetic flux density of a predetermined magnetic pole among the plurality of magnetic poles, which is positioned closest to the regulating blade when the regulating blade is fixed to the developing frame member, is recorded, the regulating blade being fixed to the developing frame member, positioned relative to the developer carrying member, and being constructed to adjust the amount of the developer carried by the developer carrying member.

[0021] Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a cross-sectional view illustrating the configuration of the image forming apparatus.

[0023] Figure 2 It is a perspective view illustrating the configuration of a developing device.

[0024] Figure 3 It is a perspective view illustrating the configuration of a developing device.

[0025] Figure 4 is a cross-sectional view illustrating the configuration of a developing device.

[0026] Figure 5 is a cross-sectional view illustrating the configuration of a developing device.

[0027] Figure 6 Schematic diagram illustrating the behavior of the developer near the regulating blade.

[0028] Figure 7A and Figure 7B It is a diagram for explaining the relationship between the SB gap and the developer coating amount.

[0029] Figure 8A 、 Figure 8B and Figure 8C It is a diagram for explaining the relationship between the adjustment range of the SB gap and the developer coating amount.

[0030] Figure 9A and Figure 9B This is a diagram for explaining the relationship between the local maximum peak value of the magnetic flux density of the regulating pole and the developer coating amount.

[0031] Figure 10A and Figure 10B This is a diagram for explaining the relationship between the local maximum peak position of the magnetic flux density of the regulating pole and the developer coating amount.

[0032] Figure 11A 、 Figure 11B and Figure 11C It is a diagram for explaining the relationship between the adjustment range of the SB gap and the developer coating amount.

[0033] Figure 12A 、 Figure 12B and Figure 12C It is a diagram for explaining the relationship between the adjustment range of the SB gap and the developer coating amount.

[0034] Figure 13A 、 Figure 13B and Figure 13C It is a diagram for explaining the relationship between the adjustment range of the SB gap and the developer coating amount.

[0035] Figure 14 This is a diagram for explaining the portion where the two-dimensional barcode of the developing sleeve is arranged.

[0036] Figure 15 It is a diagram for explaining a process of attaching a developing sleeve to a developing frame member.

[0037] Figure 16 It is a diagram for explaining the process of acquiring the characteristics of the magnet from the developing sleeve.

[0038] Figure 17A and Figure 17B It is a diagram for explaining a process of fixing the regulating blade to the developing frame member.

[0039] Figure 18A and Figure 18B It is a diagram for explaining the relationship between the adjustment range of the SB gap and the developer coating amount.

[0040] Figure 19A 、 Figure 19B and Figure 19C It is a diagram for explaining the deflection of the outer diameter of the developing sleeve.

[0041] Figure 20 This is a diagram for explaining a portion where a phase recognition portion of a developing sleeve is provided. DETAILED DESCRIPTION

[0042] Various exemplary embodiments, features, and aspects of the present invention are described in detail below with reference to the accompanying drawings. Furthermore, the following exemplary embodiments are not intended to limit the present invention as defined in the claims, and furthermore, not all combinations of features described in the following exemplary embodiments are essential to the present invention's solution. The present invention can be implemented in a variety of applications, such as printers, various types of printing presses, copiers, fax machines, and multifunction peripherals.

[0043] <Structure of Image Forming Apparatus>

[0044] First, refer to Figure 1 The configuration of the image forming apparatus according to the first exemplary embodiment of the present invention will be described with reference to a cross-sectional view of FIG. Figure 1 As shown in FIG, the image forming apparatus 60 includes an intermediate transfer belt (ITB) 61 having an endless shape serving as an intermediate transfer member, and an intermediate transfer belt 61 extending in a rotation direction ( Figure 1 Four image forming units 600 are arranged from the upstream side to the downstream side (in the direction of arrow C in FIG). The image forming units 600 form toner images of yellow (Y), magenta (M), cyan (C), and black (Bk), respectively.

[0045] Each image forming unit 600 includes a rotatable photosensitive drum 1 serving as an image bearing member. In addition, each image forming unit 600 also includes a rotating drum 1 along the rotation direction ( Figure 1 A charging roller 2 serving as a charging unit, a developing device 3 serving as a developing unit, a primary transfer roller 4 serving as a primary transfer unit, and a photosensitive member cleaner 5 serving as a photosensitive member cleaning unit are arranged (in the direction of arrow E in FIG).

[0046] Each developing device 3 can be attached to and detached from the image forming device 60. Each developing device 3 includes a developing container that accommodates a two-component developer (hereinafter referred to as "developer") containing a non-magnetic colorant (hereinafter referred to as "toner") and a magnetic carrier. In addition, a toner box that accommodates the toner of each color Y, M, C and Bk can be attached to and detached from the image forming device 60. The toner of each color Y, M, C and Bk is supplied to each developing container via a toner conveying channel. In addition, referring to Figures 2 to 5 The details of the developing device 3 will be described.

[0047] The intermediate transfer belt 61 is supported to extend between the tension roller 6, the driven roller 7a, the primary transfer roller 4, the driven roller 7b and the secondary transfer inner roller 66, and is driven to extend between the tension roller 6, the driven roller 7a, the primary transfer roller 4, the driven roller 7b and the secondary transfer inner roller 66. Figure 1 The secondary transfer inner roller 66 is also used as a driving roller for driving the intermediate transfer belt 61. As the secondary transfer inner roller 66 rotates, the intermediate transfer belt 61 is moved in the direction of the arrow C in FIG. Figure 1 Rotate in the direction of arrow C.

[0048] The intermediate transfer belt 61 is pressed from the reverse side by the primary transfer roller 4. The intermediate transfer belt 61 is brought into contact with the photosensitive drum 1 to form a primary transfer nip serving as a primary transfer portion therebetween.

[0049] An intermediate transfer member cleaner 8, serving as a belt cleaning unit, is held in contact with a position facing the tension roller 6 across the intermediate transfer belt 61. Furthermore, a secondary transfer outer roller 67, serving as a secondary transfer unit, is arranged across the intermediate transfer belt 61 at a position facing the secondary transfer inner roller 66. The intermediate transfer belt 61 is sandwiched between the secondary transfer inner roller 66 and the secondary transfer outer roller 67. This forms a secondary transfer nip, serving as a secondary transfer portion between the secondary transfer outer roller 67 and the intermediate transfer belt 61. In the secondary transfer nip, a predetermined pressure and transfer bias (electrostatic charge bias) are applied, causing a toner image to be attracted to and formed on the surface of a sheet S (e.g., paper or film).

[0050] The sheets S are stored in a stacked state in a sheet storage unit 62 (e.g., a feed cassette or a feed table). The feed unit 63 uses, for example, a feed roller to feed the sheets S in a manner consistent with image formation timing, using, for example, a friction separation method. The sheets S fed by the feed unit 63 are conveyed to registration rollers 65 positioned along a conveyance path 64. After skew correction and timing correction are performed by the registration rollers 65, the sheets S are conveyed to the secondary transfer nip. In the secondary transfer nip, the sheets S are aligned with the toner image in terms of timing, so that secondary transfer is performed.

[0051] The fixing device 9 is arranged at the downstream side of the secondary transfer nip in the conveyance direction of the sheet S. The predetermined pressure and predetermined heat applied by the fixing device 9 to the sheet S conveyed to the fixing device 9 cause the toner image to melt and be firmly fixed to the surface of the sheet S. The sheet S having the image fixed thereto in the above-described manner is directly discharged to the discharge tray 601 by the forward rotation of the discharge roller 69.

[0052] In the case of duplex image formation, after the sheet S is conveyed by the forward rotation of the discharge rollers 69 until the trailing edge of the sheet S passes through the diverter 602, the discharge rollers 69 are rotated backward. This causes the sheet S to switch between its leading edge and trailing edge and to be conveyed to the duplex conveyance path 603. Thereafter, in synchronization with the timing of the next image formation, the sheet S is conveyed again to the conveyance path 64 by the re-feed rollers 604.

[0053] <Image Formation Process>

[0054] During image formation, the photosensitive drum 1 is driven to rotate by a motor. The charging roller 2 previously charges the surface of the photosensitive drum 1 being driven to rotate. The exposure device 68 forms an electrostatic latent image on the surface of the photosensitive drum 1 charged by the charging roller 2 based on a signal representing image information input to the image forming apparatus 60. The photosensitive drum 1 enables electrostatic latent images of various sizes to be formed thereon.

[0055] The developing device 3 includes a rotatable developing sleeve 70 serving as a developer carrying member for carrying a developer. The developing device 3 develops the electrostatic latent image formed on the surface of the photosensitive drum 1 by using the developer carried on the surface of the developing sleeve 70. This causes the toner to adhere to the surface of the photosensitive drum 1, thereby forming a visible image. A transfer bias (electrostatic charge bias) is applied to the primary transfer roller 4, so that the toner image formed on the surface of the photosensitive drum 1 is transferred to the intermediate transfer belt 61. The toner (transfer residual toner) that remains slightly on the surface of the photosensitive drum 1 after the primary transfer is recovered by the photosensitive member cleaner 5 and is then prepared for the next image forming process.

[0056] The image forming process for each color, which is performed in parallel by the image forming units 600 for each color Y, M, C, and Bk, is performed at such a timing that each toner image is sequentially superimposed on the toner image of the color on the upstream side that has been primarily transferred to the intermediate transfer belt 61. As a result, a full-color toner image is formed on the intermediate transfer belt 61, and the toner image is then conveyed to the secondary transfer nip. A transfer bias is applied to the secondary transfer outer roller 67, causing the toner image formed on the intermediate transfer belt 61 to be transferred to the sheet S conveyed to the secondary transfer nip. The toner (residual transfer toner) that remains slightly on the intermediate transfer belt 61 after the sheet S passes through the secondary transfer nip is recovered by the intermediate transfer member cleaner 8. The fixing device 9 fixes the toner image transferred to the sheet S. The sheet S that has been fixed by the fixing device 9 is discharged to the discharge tray 601.

[0057] After a series of image forming processes as described above are completed, preparations are made for the next image forming operation.

[0058] <Structure of Developing Device>

[0059] Next, refer to Figure 2 Stereoscopic image, Figure 3 Stereoscopic image, Figure 4 Cross-sectional view and Figure 5 The configuration of the developing device 3 will be described with reference to a cross-sectional view of FIG. Figure 4 yes Figure 2 1 is a sectional view of the developing device 3 in the cross section H shown in FIG. Figure 5 This is illustrated in an enlarged manner Figure 4 Figure 70 and its surrounding parts in a cross-sectional view.

[0060] The developing device 3 includes a developing container that contains a developer including a toner and a carrier. The developing container is composed of a developing frame member 30 made of resin molded with resin and a cover frame member 37 made of resin molded with resin.

[0061] The developing frame member 30 is provided with an opening at a position corresponding to the developing region where the developing sleeve 70 faces the photosensitive drum 1. The developing sleeve 70 is positioned rotatably relative to the developing frame member 30 in such a manner that a portion of the developing sleeve 70 is exposed at the opening of the developing frame member 30. Bearings 73 serving as bearing members are provided at both end portions of the developing sleeve 70 in the longitudinal direction (the direction of the rotational axis of the developing sleeve 70). Both end portions of the developing sleeve 70 in the longitudinal direction (the direction of the rotational axis of the developing sleeve 70) are pivotally supported in a rotatable manner by the bearings 73.

[0062] The cover frame member 37 covers a portion of the opening of the development frame member 30 in such a manner that a portion of the outer peripheral surface of the development sleeve 70 is covered in the longitudinal direction of the development sleeve 70 (the direction of the rotation axis of the development sleeve 70). In addition, the cover frame member 37 can be configured to be molded integrally with the development frame member 30, or can be configured to be molded separately from the development frame member 30 and attached to the development frame member 30 as a separate member. Figure 2 、 Figure 4 and Figure 5 The state where the cover frame member 37 is attached to the developing frame member 30 is illustrated. On the other hand, Figure 3 A state in which the cover frame member 37 has not yet been attached to the developing frame member 30 is illustrated.

[0063] The interior of the development frame member 30 is partitioned into a development chamber 31 serving as a first chamber and a stirring chamber 32 serving as a second chamber by a partition wall 38 positioned so as to extend in the vertical direction. In other words, the partition wall 38 functions as a partition that separates the development chamber 31 from the stirring chamber 32. In addition, the partition wall 38 can be configured to be molded integrally with the development frame member 30, or can be configured to be molded separately from the development frame member 30 and attached to the development frame member 30 as a separate member.

[0064] The developing device 3 includes a first communicating portion 39a that enables the developer in the developing chamber 31 to be transferred from the developing chamber 31 to the stirring chamber 32, and a second communicating portion 39b that enables the developer in the stirring chamber 32 to be transferred from the stirring chamber 32 to the developing chamber 31. In this way, the developing chamber 31 and the stirring chamber 32 are connected to each other at both ends in the longitudinal direction via the first communicating portion 39a and the second communicating portion 39b.

[0065] A magnet 71 serving as a magnetic field generating unit for generating a magnetic field for causing the developer to be carried on the surface of the developing sleeve 70 is fixedly positioned inside the developing sleeve 70. The magnet 71 is a columnar magnet roller having a plurality of magnetic poles and is supported in a non-rotatable manner. Figure 5 As shown in FIG, the magnet 71 is arranged along the rotation direction ( Figure 5 The developing sleeve 70 includes an N2 pole, an S2 pole, an N3 pole, an N1 pole, and an S1 pole in order from the N2 pole, which is a developing pole positioned opposite to the photosensitive drum 1 in the developing region. Furthermore, the magnet 71 can be a magnet constructed by sticking a plurality of magnet pieces together to a metal shaft for fixing the magnet 71 inside the developing sleeve 70. Furthermore, the magnet 71 can be a magnet constructed integrally with one magnet including a magnet shaft portion for fixing the magnet 71 inside the developing sleeve 70.

[0066] The developer in the developing chamber 31 is drawn under the influence of the magnetic field caused by the magnetic poles of the magnet 71 and is thus supplied to the developing sleeve 70. Thus, since the developer is supplied from the developing chamber 31 to the developing sleeve 70, the developing chamber 31 is also referred to as a "supply chamber".

[0067] In the developing chamber 31, a first conveyor screw 33 is positioned opposite the developing sleeve 70. The first conveyor screw 33 serves as a conveying unit for stirring and conveying the developer in the developing chamber 31. The first conveyor screw 33 includes a rotating shaft serving as a rotatable shaft portion and a spiral blade portion serving as a developer conveying portion provided along the outer periphery of the rotating shaft. The first conveyor screw 33 is supported so as to be rotatable relative to the developing frame member 30. Bearing members are provided at both ends of the first conveyor screw 33 in the longitudinal direction.

[0068] Furthermore, a second conveyor screw 34 is positioned within the stirring chamber 32. The second conveyor screw 34 serves as a conveying unit that stirs the developer in the stirring chamber 32 and conveys the developer in a direction opposite to that of the first conveyor screw 33. The second conveyor screw 34 includes a rotating shaft serving as a rotatable shaft portion and a spiral blade portion serving as a developer conveying portion provided along the outer periphery of the rotating shaft. The second conveyor screw 34 is supported so as to be rotatable relative to the developing frame member 30. Bearing members are provided at both longitudinal ends of the second conveyor screw 34. When the first and second conveyor screws 33 and 34 are driven to rotate, a circulation path is formed in which the developer circulates between the developing chamber 31 and the stirring chamber 32 via the first and second connecting portions 39a and 39b.

[0069] A regulating blade 36 serving as a developer regulating member that regulates the amount of developer carried on the surface of the developing sleeve 70 (hereinafter referred to as "developer coating amount") is fixed to the developing frame member 30. Furthermore, the regulating blade 36 can be a regulating blade made of metal such as stainless steel, or can be a regulating blade made of resin by resin molding.

[0070] The regulating blade 36 is positioned in such a manner as to face the developing sleeve 70 without contacting the developing sleeve 70. Furthermore, the regulating blade 36 is positioned opposite to the developing sleeve 70 across a predetermined gap (hereinafter referred to as "SB gap G") between the regulating blade 36 and the developing sleeve 70 in the longitudinal direction of the developing sleeve 70 (the direction of the rotational axis of the developing sleeve 70). The SB gap G is assumed to be the shortest distance between the maximum image area of ​​the developing sleeve 70 and the maximum image area of ​​the regulating blade 36.

[0071] Furthermore, the maximum image area of ​​the developing sleeve 70 is an area of ​​the developing sleeve 70 corresponding to the largest image area among image areas capable of forming an image on the surface of the photosensitive drum 1 with respect to the direction of the rotational axis of the developing sleeve 70. Furthermore, the maximum image area of ​​the regulating blade 36 is an area of ​​the regulating blade 36 corresponding to the largest image area among image areas capable of forming an image on the surface of the photosensitive drum 1 with respect to the direction of the rotational axis of the developing sleeve 70.

[0072] In the first exemplary embodiment, since the photosensitive drum 1 enables electrostatic latent images to be formed thereon in multiple sizes, the maximum image area is assumed to refer to an image area corresponding to the maximum size (e.g., A3 size) among image areas of multiple sizes capable of forming an image on the surface of the photosensitive drum 1. On the other hand, in a modified example in which the photosensitive drum 1 enables electrostatic latent images to be formed thereon in only a single size, the maximum image area is assumed to be replaced with an image area of ​​a single size capable of forming an image on the surface of the photosensitive drum 1.

[0073] Next, refer to Figure 6 The behavior of the developer near the regulating blade 36 is described with reference to a schematic diagram.

[0074] like Figure 5 As shown in FIG, the S1 pole is a magnetic pole located closest to the regulating blade 36 among the plurality of magnetic poles (N2 pole, S2 pole, N3 pole, N1 pole, and S1 pole) included in the magnet 71 and is hereinafter referred to as “regulating pole S1”.

[0075] The regulating blade 36 is positioned approximately opposite to the local maximum peak position of the magnetic flux density of the regulating pole S1. In other words, the regulating blade 36 is positioned opposite to the surface of the developing sleeve 70 within a range of ±10 degrees in the rotational direction of the developing sleeve 70, centered at the local maximum peak position of the magnetic flux density of the regulating pole S1.

[0076] The developer supplied from the developing chamber 31 to the developing sleeve 70 is affected by the magnetic field caused by the multiple magnetic poles included in the magnet 71. In addition, the developer regulated and scraped by the regulating blade 36 tends to stagnate in the upstream portion of the SB gap G. As a result, a developer accumulation forms on the upstream side of the regulating blade 36 in the rotation direction of the developing sleeve 70. Then, the developer that is part of the developer accumulation is transported through the SB gap G in such a manner as to be associated with the rotation of the developing sleeve 70. At this time, the layer thickness of the developer passing through the SB gap G is adjusted by the regulating blade 36. In this way, a thin layer of developer is formed on the surface of the developing sleeve 70. Then, a predetermined amount of developer carried on the surface of the developing sleeve 70 is transported to the developing area in association with the rotation of the developing sleeve 70. Therefore, adjusting the size of the SB gap G results in adjusting the amount of developer transported to the developing area.

[0077] The developer transported to the developing area magnetically stands up at the developing area, thereby forming a magnetic brush. The formed magnetic brush contacts the photosensitive drum 1, so that the colorant contained in the developer is supplied to the photosensitive drum 1. Then, the electrostatic latent image formed on the surface of the photosensitive drum 1 is developed into a colorant image. The developer remaining on the surface of the developing sleeve 70 after passing through the developing area and supplying the colorant to the photosensitive drum 1 (hereinafter referred to as "developed developer") is scraped off from the surface of the developing sleeve 70 by the repulsive magnetic field formed between the magnetic poles of the same polarity of the magnet 71. The developed developer scraped off from the surface of the developing sleeve 70 falls into the developing chamber 31, thereby being recovered to the developing chamber 31.

[0078] <Developer Coating Amount>

[0079] Next, refer to Figure 7A and Figure 7B The relationship between the size of the SB gap G and the developer coating amount is described.

[0080] like Figure 7A As shown in , the relationship between the size of the SB gap G and the developer coating amount is generally such a relationship that as the size of the SB gap G becomes larger, the developer coating amount becomes larger.

[0081] The permissible range of developer coating amount is determined in advance to ensure the quality level of the image formed on the surface of the photosensitive drum 1. The permissible range of developer coating amount is hereinafter referred to as "amount of change in developer coating amount (ΔM)".

[0082] like Figure 7B As shown in , the correlation between the size of the SB gap G and the developer coating amount has a variation width of ΔM. Examples of causes of variation in ΔM include environmental changes, changes over time, component tolerances, and adjustment tolerances. Therefore, considering the variation width of such ΔM, the present exemplary embodiment determines the adjustment range of the SB gap G (in other words, the upper and lower limits of the SB gap G) so that the developer coating amount satisfies ΔM. Specifically, the present exemplary embodiment determines that the size of the SB gap G, based on which the developer coating amount reaches the center value of ΔM, is the center value of the adjustment range of the SB gap G (the target value of the SB gap G).

[0083] Next, refer to Figure 8A 、 Figure 8B and Figure 8C The relationship between the adjustment range of the SB gap G and the developer coating amount will be described.

[0084] In the case of large changes in ΔM, such as Figure 8AAs shown in , the range of the permissible size of the SB gap G (the adjustment range of the SB gap G) is narrowed. On the other hand, when the change in ΔM is small, as shown in Figure 8B As shown in , the range of the size of the permissible SB gap G (the adjustment range of the SB gap G) is widened. Figure 8C As shown in FIG, in the case where the change in ΔM is small and the adjustment range of the SB gap G is set narrow, the change amount (ΔM) of the developer coating amount is all Therefore, in order to ensure that the developer coating amount is uniform in the longitudinal direction of the developing sleeve 70 (the rotational axis direction of the developing sleeve 70), the change in ΔM needs to be made smaller.

[0085] Next, refer to Figure 9A and Figure 9B The relationship between the change in the “local maximum peak value” of the magnetic flux density of the regulation pole S1 of each individual magnet 71 and the developer coating amount will be described.

[0086] Figure 9A The distribution of the magnitude of the magnetic force (magnetic lines of force) near the regulating pole S1 is illustrated. The "local maximum peak" of the magnetic flux density of the regulating pole S1 can vary for each individual magnet 71. This is because, in the case of manufacturing a magnet roller having multiple magnetic poles, the "local maximum peak" of the magnetic flux density of each magnetic pole is adjusted by magnetizing the magnet 71 in the order of, for example, the developing pole N2, the magnetic pole for scraping off the developer (scraping pole) N3, and the regulating pole S1. Therefore, the "local maximum peak" of the magnetic flux density of the regulating pole S1 can vary according to the relative relationship with the "local maximum peak" of the magnetic flux density of the developing pole N2 or the "local maximum peak" of the magnetic flux density of the scraping pole N3.

[0087] like Figure 9A As shown in FIG, a change in the "local maximum peak value" of the magnetic flux density of the regulating pole S1 of each individual magnet 71 causes a change in the distribution of the magnitude of the magnetic force near the regulating pole S1, which changes the behavior of the developer near the regulating blade 36 or the density of the developer. As a result, the amount of developer passing through the SB gap G (the amount of developer coating) changes, so that there is a possibility that the amount of developer coating may change for each individual developing device 3.

[0088] For example, it is assumed that the size of the SB gap G is set at the same value regardless of individual differences in the “local maximum peak value” of the magnetic flux density of the regulating pole S1 of the magnet 71. In this case, as Figure 9B As shown in FIG, due to the variation of the “local maximum peak value” of the magnetic flux density of the regulating pole S1 for each individual magnet 71, the developer coating amount will vary by an amount corresponding to the individual difference in the “local maximum peak value” of the magnetic flux density of the regulating pole S1 (referred to as “ΔM x ”).

[0089] Next, refer to Figure 10A and Figure 10B The relationship between the change in the “local maximum peak position” of the magnetic flux density of the regulation pole S1 of each individual magnet 71 and the developer coating amount will be described.

[0090] Figure 10A The upper limit value and the lower limit value of the "local maximum peak position" of the magnetic flux density of the regulating pole S1 are illustrated. The "local maximum peak position" of the magnetic flux density of the regulating pole S1 may vary for each individual magnet 71. This is because, in the case of manufacturing a magnet roller having a plurality of magnetic poles, the "local maximum peak position" of the magnetic flux density of each magnetic pole is adjusted by magnetizing the magnet 71 in the order of, for example, the developing pole N2, the magnetic pole for scraping off the developer (scraping pole) N3, and the regulating pole S1. Therefore, the "local maximum peak position" of the magnetic flux density of the regulating pole S1 may vary according to the relative relationship with the "local maximum peak position" of the magnetic flux density of the developing pole N2 or the "local maximum peak position" of the magnetic flux density of the scraping pole N3.

[0091] The change in the "local maximum peak position" of the magnetic flux density of the regulating pole S1 for each individual magnet 71 causes a change in the distribution of the magnitude of the magnetic force near the regulating pole S1, which changes the behavior of the developer near the regulating blade 36 or the density of the developer. As a result, the amount of developer passing through the SB gap G (the amount of developer applied) changes, so there is a possibility that the amount of developer applied may change for each individual developing device 3.

[0092] For example, it is assumed that the size of the SB gap G is set at the same value regardless of individual differences in the “local maximum peak position” of the magnetic flux density of the regulating pole S1 of the magnet 71. In this case, as Figure 10B As shown in FIG, due to the variation of the “local maximum peak position” of the magnetic flux density of the regulating pole S1 for each individual magnet 71, the developer coating amount will vary by an amount corresponding to the individual difference in the “local maximum peak position” of the magnetic flux density of the regulating pole S1 (referred to as “ΔM y ”).

[0093] In this way, changes in characteristics for each individual magnet 71 such as the “local maximum peak value” and the “local maximum peak position” of the magnetic flux density of the adjustment pole S1 result in changes in the distribution of the magnitude of the magnetic force near the adjustment pole S1 .

[0094] For example, when the "local maximum peak value" of the magnetic flux density of the regulating pole S1 is large, the magnitude of the magnetic force acting on the carrier contained in the developer that is in contact with the upstream side of the regulating blade 36 with respect to the rotational direction of the developing sleeve 70 tends to increase. Therefore, when the "local maximum peak value" of the magnetic flux density of the regulating pole S1 is greater than a predetermined value, the developer coating amount obtained when the size of the SB gap G is set to the same value becomes larger than when the "local maximum peak value" of the magnetic flux density of the regulating pole S1 is the predetermined value.

[0095] On the other hand, when the "local maximum peak value" of the magnetic flux density of the regulating pole S1 is small, the magnitude of the magnetic force acting on the carrier contained in the developer that is in contact with the upstream side of the regulating blade 36 with respect to the rotational direction of the developing sleeve 70 tends to decrease. Therefore, when the "local maximum peak value" of the magnetic flux density of the regulating pole S1 is smaller than a predetermined value, the developer coating amount obtained when the size of the SB gap G is set to the same value becomes smaller than when the "local maximum peak value" of the magnetic flux density of the regulating pole S1 is the predetermined value.

[0096] In this way, when the size of the SB gap G is set at the same value without considering the local maximum peak value of the magnetic flux density of the adjustment pole S1, variations in the developer coating amount for each individual developing device 3 may occur due to variations in the local maximum peak value of the magnetic flux density of the adjustment pole S1 for each individual magnet 71. Therefore, in order to prevent or reduce variations in the developer coating amount for each individual developing device 3, it is desirable to adjust the size of the SB gap G for each individual developing device 3 in consideration of the “local maximum peak value” of the magnetic flux density of the adjustment pole S1 for each individual magnet 71. The first aspect of the present invention is intended to prevent or reduce variations in the developer coating amount for each individual developing device 3 by adjusting the size of the SB gap G in consideration of the “local maximum peak value” of the magnetic flux density of the adjustment pole S1 included in the magnet 71.

[0097] Similarly, in the case where the size of the SB gap G is set at the same value without considering the local maximum peak position of the magnetic flux density of the adjustment pole S1, variations in the developer coating amount may occur for each individual developing device 3 due to variations in the local maximum peak position of the magnetic flux density of the adjustment pole S1 for each individual magnet 71. Therefore, in order to prevent or reduce variations in the developer coating amount for each individual developing device 3, it is desirable to adjust the size of the SB gap G for each individual developing device 3 in consideration of the “local maximum peak position” of the magnetic flux density of the adjustment pole S1 for each individual magnet 71. The second aspect of the present invention is intended to prevent or reduce variations in the developer coating amount for each individual developing device 3 by adjusting the size of the SB gap G in consideration of the “local maximum peak position” of the magnetic flux density of the adjustment pole S1 included in the magnet 71.

[0098] Details of each of the first and second aspects of the present invention are described below.

[0099] First, refer to Figure 11A 、 Figure 11B and Figure 11C 、 Figure 12A 、 Figure 12B and Figure 12C as well as Figure 13A 、 Figure 13B and Figure 13C The relationship between the adjustment range of the SB gap G and the developer coating amount will be described.

[0100] Figure 11A The relationship between the adjustment range of the SB gap G and the developer coating amount is illustrated when the "local maximum peak value" of the magnetic flux density of the adjustment pole S1 is the center value and the "local maximum peak position" of the magnetic flux density of the adjustment pole S1 is the center value. Figure 11A In the example shown in , as a characteristic of the magnet 71 , the relationship between the size of the SB gap G and the developer coating amount (in other words, the sensitivity of the change in ΔM to the developer coating amount) is represented by a “characteristic line L1 ”.

[0101] In the case where the characteristic of the magnet 71 is the “characteristic line L1”, there is no need to consider the portion of the developer coating amount corresponding to the individual difference in the “local maximum peak value” of the magnetic flux density of the regulating pole S1 and the portion of the developer coating amount corresponding to the individual difference in the “local maximum peak position” of the magnetic flux density of the regulating pole S1 (see Figure 12A ). In addition, Figure 11A The variation of the developer coating amount corresponding to the individual difference of the “local maximum peak value” of the magnetic flux density of the regulating pole S1 is represented by “ΔM x ", and the variation of the developer coating amount corresponding to the individual difference of the "local maximum peak position" of the magnetic flux density of the regulating pole S1 is represented by "ΔMy "express.

[0102] Furthermore, when the characteristic of the magnet 71 is the "characteristic line L1", the adjustment range of the SB gap G can be extended to the range where the "characteristic line L1" intersects with the upper limit and lower limit lines of ΔM (see Figure 13A ).

[0103] Figure 11B The relationship between the adjustment range of the SB gap G and the developer coating amount is illustrated when the "local maximum peak value" of the magnetic flux density of the adjustment pole S1 is the lower limit value and the "local maximum peak position" of the magnetic flux density of the adjustment pole S1 is the lower limit value. Figure 11B In the example shown in , as a characteristic of the magnet 71 , the relationship between the size of the SB gap G and the developer coating amount (in other words, the sensitivity of the change in ΔM to the developer coating amount) is represented by a “characteristic line L2 ”.

[0104] When the characteristic of the magnet 71 is the "characteristic line L2", the "local maximum peak value" of the magnetic flux density of the adjustment pole S1 is shifted to the lower limit value side, and the "local maximum peak position" of the magnetic flux density of the adjustment pole S1 is shifted to the lower limit value side (see Figure 12B ). In addition, when the characteristic of the magnet 71 is the "characteristic line L2", the adjustment range of the SB gap G can be extended to the range where the "characteristic line L2" intersects with the upper limit and lower limit lines of ΔM (see Figure 13B ). In this case, by using Figure 13B , the size of the SB gap G corresponding to the target value of the developer coating amount on the “characteristic line L2 ” can be determined as the target value of the SB gap G.

[0105] Figure 11C The relationship between the adjustment range of the SB gap G and the developer coating amount is illustrated when the "local maximum peak value" of the magnetic flux density of the adjustment pole S1 is the upper limit value and the "local maximum peak position" of the magnetic flux density of the adjustment pole S1 is the upper limit value. Figure 11C In the example shown in , as a characteristic of the magnet 71 , the relationship between the size of the SB gap G and the developer coating amount (in other words, the sensitivity of the change in ΔM to the developer coating amount) is represented by a “characteristic line L3 ”.

[0106] When the characteristic of the magnet 71 is the "characteristic line L3", the "local maximum peak value" of the magnetic flux density of the adjustment pole S1 is shifted to the upper limit value side, and the "local maximum peak position" of the magnetic flux density of the adjustment pole S1 is shifted to the upper limit value side (see Figure 12C). In addition, when the characteristic of the magnet 71 is the "characteristic line L3", the adjustment range of the SB gap G can be extended to the range where the "characteristic line L3" intersects with the upper limit and lower limit lines of ΔM (see Figure 13C ). In this case, by using Figure 13C , the size of the SB gap G corresponding to the target value of the developer coating amount on the “characteristic line L3 ” can be determined as the target value of the SB gap G.

[0107] Furthermore, the fact that the “local maximum peak value” of the magnetic flux density of the regulating pole S1 is the center value, the lower limit value, or the upper limit value means that it is the median value, the minimum value, or the maximum value, respectively, within the range of the “local maximum peak value” of the magnetic flux density of the regulating pole S1 that can be obtained for each individual magnet 71. Furthermore, the fact that the “local maximum peak position” of the magnetic flux density of the regulating pole S1 is the center value, the lower limit value, or the upper limit value means that it is the median value, the minimum value, or the maximum value, respectively, within the range of the “local maximum peak position” of the magnetic flux density of the regulating pole S1 that can be obtained for each individual magnet 71.

[0108] In the case where the characteristic of the magnet 71 is the “characteristic line L2” or the “characteristic line L3”, the center value of ΔM deviates from the center value in the case where the characteristic of the magnet 71 is the “characteristic line L1” (see Figures 11A to 11C ). Therefore, when the size of the SB gap G is set at the same value without considering the characteristics of each individual magnet 71, the amount of developer applied will vary for each individual developing device 3. Therefore, in order to prevent or reduce the variation in the amount of developer applied for each individual developing device 3, it is necessary to shift the range of the size of the SB gap G for each individual developing device 3 by considering the characteristics of the magnet 71.

[0109] Therefore, in the case where the characteristics of the magnet 71 deviate from the center value of ΔM obtained in the case of the “characteristic line L1”, the present exemplary embodiment determines the adjustment range of the SB gap G in such a manner that the developer coating amount on the “characteristic line L1” is used as the developer coating amount as a target. Figure 12B As shown in , in the case where the characteristic of the magnet 71 is the “characteristic line L2”, the present exemplary embodiment shifts the adjustment range of the SB gap G in such a manner that the center value of the adjustment range of the SB gap G (the target value of the SB gap G) becomes larger. On the other hand, as Figure 12C As shown in , when the characteristic of the magnet 71 is the “characteristic line L3 ”, the present exemplary embodiment shifts the adjustment range of the SB gap G in such a manner that the center value of the adjustment range of the SB gap G (the target value of the SB gap G) becomes smaller.

[0110] According to the above Figures 11A to 11C 、 12A to 12C as well as 13A to 13C, the adjustment range of the SB gap G can be determined by considering the "local maximum peak" of the magnetic flux density of the adjustment pole S1 or the "local maximum peak position" of the magnetic flux density of the adjustment pole S1 for each individual magnet 71. In addition, the method for determining the adjustment range of the SB gap G is not limited to using the characteristic lines L1, L2, and L3 (such as Figures 11A to 11C 、 12A to 12C as well as 13A to 13C In addition to determining by using the characteristic line shown in , it is also possible to determine by referring to a table that can be converted into an adjustment range of the SB gap G.

[0111] <How to fix the adjustment blade>

[0112] As described above, the change in the developer coating amount (ΔM) is caused by the change in the "local maximum peak" or "local maximum peak position" of the magnetic flux density of the regulating pole S1 for each individual magnet 71, which causes a change in the distribution of the magnitude of the magnetic force near the regulating pole S1.

[0113] Therefore, this method calculates the actual measured value of the "local maximum peak value" or "local maximum peak position" of the magnetic flux density of the regulating pole S1 for each individual magnet 71, and records information about the "local maximum peak value" or "local maximum peak position" of the magnetic flux density of the regulating pole S1 on the developing sleeve 70 using a two-dimensional barcode. Then, when the regulating blade 36 is secured to the developing frame member 30, the device reads the two-dimensional barcode provided on the developing sleeve 70 to obtain (input) the information about the "local maximum peak value" or "local maximum peak position" of the magnetic flux density of the regulating pole S1 recorded on the developing sleeve 70. Next, the device determines the adjustment range of the SB gap G based on the information about the "local maximum peak value" or "local maximum peak position" of the magnetic flux density of the regulating pole S1 recorded on the developing sleeve 70. The device then secures the regulating blade 36 to the developing frame member 30 so that the size of the SB gap G in the longitudinal direction of the developing sleeve 70 falls within the determined adjustment range of the SB gap G (in other words, between the upper and lower limits of the SB gap G). The details are described below.

[0114] First, refer to Figure 14 The portion of the developing sleeve 70 provided with the two-dimensional barcode will be described. Figure 14 It is a diagram illustrating an end portion of the developing sleeve 70 in the longitudinal direction in an enlarged manner.

[0115] In the first exemplary embodiment, a two-dimensional barcode is used as a method for recording information about the "local maximum peak" or "local maximum peak position" of the magnetic flux density of the regulating pole S1 on the developing sleeve 70. The portion of the developing sleeve 70 provided with the two-dimensional barcode only needs to be a portion at which the device can read the two-dimensional barcode when the developing sleeve 70 is supported by the developing frame member 30. For example, the portion (70d) of the developing sleeve 70 provided with the two-dimensional barcode is the end in the longitudinal direction of the shaft portion (magnet shaft) of the magnet for fixing the magnet 71 to the interior of the developing sleeve 70. In addition, the magnet shaft is one of the components constituting the developing sleeve 70. In addition, for example, the portion (70d) of the developing sleeve 70 provided with the two-dimensional barcode can be a flange portion positioned at the end in the longitudinal direction of the developing sleeve 70 and capable of rotating integrally with the developing sleeve 70.

[0116] Furthermore, a modified example can be employed in which actual measured values ​​of the local maximum peak value or the local maximum peak position of the magnetic flux density of the regulating pole S1 are calculated for each individual magnet 71, and information regarding the local maximum peak value or the local maximum peak position of the magnetic flux density of the regulating pole S1 is recorded on the magnet 71 using a two-dimensional barcode. In this modified example, for example, the magnet 71 is fixedly positioned inside the developing sleeve 70, and the device reads the two-dimensional barcode of the magnet 71 while the flange portion is attached to one longitudinal end of the developing sleeve 70. After the device reads the two-dimensional barcode of the magnet 71, the flange portion is attached to the other longitudinal end of the developing sleeve 70, and the developing sleeve 70 can then be supported by the developing frame member 30. The portion of the magnet 71 provided with the two-dimensional barcode only needs to be the portion where the device can read the two-dimensional barcode while the magnet 71 is fixedly positioned inside the developing sleeve 70 and the flange portion is attached to one longitudinal end of the developing sleeve 70.

[0117] In the first exemplary embodiment, the actual measured value of the "local maximum peak value" of the magnetic flux density of the regulating pole S1 or the actual measured value of the "local maximum peak position" of the magnetic flux density of the regulating pole S1 is recorded on the developing sleeve 70 using a two-dimensional barcode. Furthermore, the "local maximum peak position" of the magnetic flux density of the regulating pole S1 can be calculated by measuring the angle from a phase determination unit that determines the phase of the magnet 71. The phase determination unit is provided at the longitudinal end of the shaft portion of the magnet that secures the magnet 71 to the interior of the developing sleeve 70.

[0118] The device reads the two-dimensional barcode provided on the developing sleeve 70 to obtain information about the "local maximum peak value" or "local maximum peak position" of the magnetic flux density of the regulating pole S1 included in the magnet 71 fixedly positioned inside the developing sleeve 70. The device then associates the information about the "local maximum peak value" or "local maximum peak position" of the magnetic flux density of the regulating pole S1 obtained from the developing sleeve 70 with the unit that supports the developing sleeve 70 by the developing frame member 30.

[0119] Furthermore, it is desirable that the two-dimensional barcode provided on the developing sleeve 70 be read by the apparatus in a state where the developing sleeve 70 is supported by the developing frame member 30. This is to prevent an error in the association between the unit supporting the developing sleeve 70 by the developing frame member 30 and the information on the "local maximum peak value" or "local maximum peak position" of the magnetic flux density of the regulating pole S1.

[0120] Here, let's consider a case where the size of the SB gap G is adjusted at each of the two end portions and the central portion in the longitudinal direction of the maximum image area of ​​the developing sleeve 70. In this case, information regarding the "local maximum peak value" or "local maximum peak position" of the magnetic flux density of the regulating pole S1 at each of the two end portions and the central portion in the longitudinal direction of the magnet 71 can be recorded on the developing sleeve 70 using a two-dimensional barcode. In other words, consistent with the conditions used when adjusting the SB gap G, information regarding the "local maximum peak value" or "local maximum peak position" of the magnetic flux density of the regulating pole S1 at each of multiple portions in the longitudinal direction of the magnet 71 can be recorded on the developing sleeve 70 using a two-dimensional barcode.

[0121] Next, refer to Figure 15 The process of attaching the developing sleeve 70 to the developing frame member 30 will be described. Figure 15 As shown in , before fixing the regulating blade 36 to the developing frame member 30, the developing sleeve 70 provided with a two-dimensional barcode is previously attached to the developing frame member 30. This enables calculation of the size of the SB gap G in a state where the developing sleeve 70 is supported by the developing frame member 30.

[0122] Next, refer to Figure 16 A process of acquiring, from the developing sleeve 70 , the characteristics of the magnet 71 fixedly positioned inside the developing sleeve 70 will be described.

[0123] like Figure 16 As shown in , in a state where the developing sleeve 70 is attached to the developing frame member 30 , the device 100 reads a two-dimensional barcode provided on the developing sleeve 70 to obtain information on the “local maximum peak value” or “local maximum peak position” of the magnetic flux density of the regulating pole S1 .

[0124] Next, the device 100 determines the size of the SB gap G for adjusting the size of the SB gap G based on the information on the “local maximum peak value” or “local maximum peak position” of the magnetic flux density of the regulating pole S1 obtained from the developing sleeve 70. Specifically, the device 100 specifies the characteristics of the magnet 71 (see above) based on the information on the “local maximum peak value” or “local maximum peak position” of the magnetic flux density of the regulating pole S1 obtained from the developing sleeve 70. Figures 11A to 11C The apparatus 100 then determines, based on the characteristics of the magnet 71 (characteristic line L1, characteristic line L2, or characteristic line L3), the size of the SB gap G corresponding to the target value of the developer coating amount on the characteristic line as the target value of the size of the SB gap G. The apparatus 100 then prevents or reduces variations (ΔM) in the developer coating amount for each individual developing device 3 by adjusting the upper limit value and the lower limit value serving as the adjustment range of the SB gap G.

[0125] Next, refer to Figure 17A and Figure 17B A fixing process of fixing the regulating blade 36 to the developing frame member 30 will be described.

[0126] like Figure 17A and Figure 17B As shown in FIG, the apparatus adjusts the position at which the regulating blade 36 is to be fixed to the developing frame member 30 so that the size of the SB gap G falls within the determined adjustment range of the SB gap G. For example, while observing the longitudinal ends of the maximum image area of ​​the developing sleeve 70 and the longitudinal ends of the regulating blade 36 via a sensor (a camera or laser device), for example, the apparatus moves the regulating blade 36 so that the size of the SB gap G falls within the adjustment range of the SB gap G. Furthermore, instead of measuring the size of the SB gap G via a sensor, for example, a method can be employed in which the size of the SB gap G is measured by striking the SB gap G with a spacer, for example. Then, when the size of the SB gap G falls within the predetermined range, the apparatus fixes the regulating blade 36 to the developing frame member 30.

[0127] More specifically, assume that the SB gap G calculated at the initial position where the regulating blade 36 has landed on the development frame member 30 is 350 μm. On the other hand, assume that the adjustment range of the SB gap G is 300 μm ± 30 μm, and that a tolerance of up to 60 μm is permissible as the SB gap G tolerance (in other words, the tolerance of the target value of the SB gap G). In this case, in the initial position where the regulating blade 36 has landed on the development frame member 30, the adjustment range of the SB gap G is 50 μm greater than 300 μm, which is the nominal value of the SB gap G. Therefore, while the regulating blade 36 is gripped with the fingers, the device causes the regulating blade 36 to translate by 50 μm in a direction that moves the regulating blade 36 closer to the surface of the development sleeve 70.

[0128] Then, the camera reads the position closest to the adjustment blade 36 translated by the finger and the front end portion of the adjustment blade 36 translated by the finger. Next, the device calculates the SB gap G again for the adjustment blade 36 translated by the finger.

[0129] When it is determined that the calculated size of the SB gap G falls within the range of the adjustment value of the SB gap G (300 μm ± 30 μm), the apparatus ends the adjustment of the SB gap G. On the other hand, when it is determined that the calculated size of the SB gap G does not fall within the adjustment range of the SB gap G (300 μm ± 30 μm), the apparatus repeats the above-described adjustment of the SB gap G until the calculated size of the SB gap G falls within the adjustment range of the SB gap G (300 μm ± 30 μm). In this manner, the apparatus fixes the regulating blade 36 to the developing frame member 30 while the size of the SB gap G is set within the predetermined range (the range of the adjustment value of the SB gap G).

[0130] Furthermore, in the first exemplary embodiment, an example has been described in which both the "local maximum peak value" of the magnetic flux density of the regulating pole S1 and the "local maximum peak position" of the magnetic flux density of the regulating pole S1 are taken into consideration when adjusting the size of the SB gap G. On the other hand, the phase of the magnet 71 is determined by attaching a phase fixing member to a phase fixing portion provided at an end portion in the longitudinal direction of the developing sleeve 70 (an end portion in the longitudinal direction of the shaft portion of the magnet). Therefore, a phase deviation (angular deviation) between the magnet 71 and the regulating blade 36 occurs due to an angular deviation component between the regulating pole S1 and the phase fixing portion of the magnet 71, component tolerances of the phase fixing member, and tolerances of the fixing portion for fixing the regulating blade 36 to the developing frame member 30.

[0131] Therefore, the local maximum peak position of the magnetic flux density of the regulating pole S1 can be considered as a specific position, and as a change in the characteristics of each individual magnet 71, only the "local maximum peak value" of the magnetic flux density of the regulating pole S1 can be considered without considering the "local maximum peak position" of the magnetic flux density of the regulating pole S1. In this case, the amount of information to be recorded on the developing sleeve 70 as the characteristics of the magnet 71 fixed to the interior of the developing sleeve 70 can be reduced. As long as the amount of information to be recorded on the developing sleeve 70 can be reduced, the method of recording the characteristics of the magnet 71 on the developing sleeve 70 is not limited to a two-dimensional barcode. For example, information about the "local maximum peak value" of the magnetic flux density of the regulating pole S1 can be recorded directly on the developing sleeve 70 by, for example, engraving, printing, or typing numbers, characters, or symbols. Furthermore, in a modified embodiment, in which information regarding the local maximum peak value of the magnetic flux density of the regulating pole S1 is directly recorded on, for example, the developing sleeve 70 or the magnet 71 by engraving, printing, or typing numbers, characters, or symbols, a case is considered in which the user can visually identify the local maximum peak value of the magnetic flux density of the regulating pole S1. In this case, the user only needs to input the visually identified local maximum peak value of the magnetic flux density of the regulating pole S1 directly into the operating unit of the device. Therefore, there is no need to provide a reading unit for reading a two-dimensional barcode in the device, which can simplify the device structure.

[0132] Similarly, the local maximum peak value of the magnetic flux density of the regulating pole S1 can be considered as a specific value, and as a change in the characteristics of each individual magnet 71, only the "local maximum peak position" of the magnetic flux density of the regulating pole S1 can be considered without considering the "local maximum peak value" of the magnetic flux density of the regulating pole S1. In this case, the amount of information to be recorded on the developing sleeve 70 as the characteristics of the magnet 71 fixed to the interior of the developing sleeve 70 can be reduced. As long as the amount of information to be recorded on the developing sleeve 70 can be reduced, the method of recording the characteristics of the magnet 71 on the developing sleeve 70 is not limited to a two-dimensional barcode. For example, information about the "local maximum peak position" of the magnetic flux density of the regulating pole S1 can be recorded directly on the developing sleeve 70 by, for example, engraving, printing, or typing numbers, characters, or symbols. Furthermore, in a modified embodiment, information regarding the "local maximum peak position" of the magnetic flux density of the regulating pole S1 is directly recorded on, for example, the developing sleeve 70 or the magnet 71 by engraving, printing, or typing numbers, characters, or symbols, etc., and a case is considered in which the user can visually identify the local maximum peak position of the magnetic flux density of the regulating pole S1. In this case, the user only needs to input the visually identified local maximum peak position of the magnetic flux density of the regulating pole S1 directly into the operating unit of the device. Therefore, there is no need to provide a reading unit for reading the two-dimensional barcode in the device, which can simplify the device structure.

[0133] However, when adjusting the size of the target SB gap G, the effect of preventing or reducing the change in ΔM is greater when both the "local maximum peak value" and the "local maximum peak position" of the magnetic flux density of the adjustment pole S1 are considered, compared to when only one of them is considered. Therefore, if the effect of preventing or reducing the change in the developer coating amount (ΔM) is prioritized over reducing the amount of information to be recorded on the developing sleeve 70, it is possible to consider both the "local maximum peak value" and the "local maximum peak position" of the magnetic flux density of the adjustment pole S1.

[0134] In the first aspect of the present invention described above, information regarding the "local maximum peak value" of the magnetic flux density of the regulating pole S1 of the magnet 71 fixedly positioned inside the developing sleeve 70 is recorded on the developing sleeve 70. Then, when the regulating blade 36 is secured to the developing frame member 30, the information regarding the "local maximum peak value" of the magnetic flux density of the regulating pole S1 recorded on the developing sleeve 70 is retrieved by reading a two-dimensional barcode provided on the developing sleeve 70. Next, the regulating blade 36 is secured to the developing frame member 30 such that the size of the SB gap G falls within a predetermined range in the longitudinal direction of the developing sleeve 70 corresponding to the "local maximum peak value" of the magnetic flux density of the regulating pole S1 recorded on the developing sleeve 70. According to the first aspect of the present invention described above, adjusting the size of the SB gap G in consideration of the "local maximum peak value" of the magnetic flux density of the regulating pole S1 included in the magnet 71 makes it possible to prevent or reduce variations in the developer coating amount for each individual developing device 3.

[0135] Furthermore, in the second aspect of the present invention described above, information regarding the "local maximum peak position" of the magnetic flux density of the regulating pole S1 of the magnet 71 fixedly positioned inside the developing sleeve 70 is recorded on the developing sleeve 70. Then, when the regulating blade 36 is secured to the developing frame member 30, the information regarding the "local maximum peak position" of the magnetic flux density of the regulating pole S1 recorded on the developing sleeve 70 is retrieved by reading a two-dimensional barcode provided on the developing sleeve 70. Subsequently, the regulating blade 36 is secured to the developing frame member 30 such that the size of the SB gap G falls within a predetermined range in the longitudinal direction of the developing sleeve 70 corresponding to the "local maximum peak position" of the magnetic flux density of the regulating pole S1 recorded on the developing sleeve 70. According to the second aspect of the present invention described above, adjusting the size of the SB gap G in consideration of the "local maximum peak position" of the magnetic flux density of the regulating pole S1 included in the magnet 71 makes it possible to prevent or reduce variations in the developer coating amount for each individual developing device 3.

[0136] In the first aspect of the present invention described above, an example has been described in which the information to be recorded on the developing sleeve 70 is information regarding the “local maximum peak value” of the magnetic flux density of the regulating pole S1 of the magnet 71 fixedly positioned inside the developing sleeve 70. Furthermore, in the second aspect of the present invention described above, an example has been described in which the information to be recorded on the developing sleeve 70 is information regarding the “local maximum peak position” of the magnetic flux density of the regulating pole S1 of the magnet 71 fixedly positioned inside the developing sleeve 70. On the other hand, in the second exemplary embodiment, an example in which the information to be recorded on the developing sleeve 70 is information regarding the size of the SB gap G targeted for adjusting the size of the SB gap G is described below.

[0137] In the second exemplary embodiment, the actual measured value of the "local maximum peak value" of the magnetic flux density of the adjustment pole S1 of each individual magnet 71 is calculated. Next, based on the calculated "local maximum peak value" of the magnetic flux density of the adjustment pole S1, the size of the SB gap G, which is the target for adjusting the size of the SB gap G, is predetermined. The adjustment range of the SB gap G (the target value of the SB gap G) corresponding to the "local maximum peak value" of the magnetic flux density of the adjustment pole S1 is then recorded on the developing sleeve 70.

[0138] Similarly, the actual measured value of the "local maximum peak position" of the magnetic flux density of the adjustment pole S1 of each individual magnet 71 is calculated. Next, based on the calculated "local maximum peak position" of the magnetic flux density of the adjustment pole S1, the size of the SB gap G, which is the target for adjusting the size of the SB gap G, is predetermined. The adjustment range of the SB gap G (the target value of the SB gap G) corresponding to the "local maximum peak position" of the magnetic flux density of the adjustment pole S1 is then recorded on the developing sleeve 70.

[0139] However, when adjusting the target SB gap G size, considering both the "local maximum peak value" and "local maximum peak position" of the magnetic flux density of the regulating pole S1 is more effective in preventing or reducing changes in ΔM than considering only one of them. Therefore, a more desirable example is as follows. Specifically, actual measured values ​​of the "local maximum peak value" and "local maximum peak position" of the magnetic flux density of the regulating pole S1 are calculated for each individual magnet 71. Next, based on the calculated "local maximum peak value" and "local maximum peak position" of the magnetic flux density of the regulating pole S1, the size of the SB gap G targeted for adjusting the size of the SB gap G is predetermined. The adjustment range of the SB gap G (the target value of the SB gap G) corresponding to the "local maximum peak value" and "local maximum peak position" of the magnetic flux density of the regulating pole S1 is then recorded on the developing sleeve 70.

[0140] Here, consider a case where the size of the SB gap G is adjusted at each of the two end portions and the central portion in the longitudinal direction of the maximum image area of ​​the developing sleeve 70. In this case, information regarding the adjustment range of the SB gap G (the target value of the SB gap G) at each of the two end portions and the central portion in the longitudinal direction of the maximum image area of ​​the developing sleeve 70 can be recorded on the developing sleeve 70. In other words, information regarding the adjustment range of the SB gap G (the target value of the SB gap G) at each of the plurality of portions in the longitudinal direction of the maximum image area of ​​the developing sleeve 70 can be recorded on the developing sleeve 70 in accordance with the conditions used when adjusting the SB gap G.

[0141] In the second exemplary embodiment, the developing sleeve 70 on which the adjustment range of the SB gap G (the target value of the SB gap G) is recorded is attached to the developing frame member 30. Then, the apparatus 100 acquires the adjustment range of the SB gap G (the target value of the SB gap G) recorded on the developing sleeve 70 supported by the developing frame member 30. Then, the apparatus 100 adjusts the position at which the regulating blade 36 is to be fixed to the developing frame member 30 so that the size of the SB gap G falls within the acquired adjustment range of the SB gap G, and fixes the regulating blade 36 to the developing frame member 30.

[0142] In the second exemplary embodiment described above, instead of recording information about the "local maximum peak value" or "local maximum peak position" of the magnetic flux density of the regulating pole S1 on the developing sleeve 70, it is only necessary to record the adjustment range of the SB gap G (the target value of the SB gap G) on the developing sleeve 70. Therefore, in the second exemplary embodiment, the amount of information to be recorded on the developing sleeve 70 can be reduced compared to the first exemplary embodiment. As long as the amount of information to be recorded on the developing sleeve 70 can be reduced, the method of recording data on the developing sleeve 70 is not limited to a two-dimensional barcode, and the adjustment range of the SB gap G (the target value of the SB gap G) can be recorded directly on the developing sleeve 70 by, for example, engraving, printing, or typing.

[0143] In the second exemplary embodiment, an example has been described in which the information to be recorded on the developing sleeve 70 is the adjustment range of the SB gap G (the target value of the SB gap G). On the other hand, in the third exemplary embodiment, an example in which the information to be recorded on the developing sleeve 70 is information on the level of the size of the SB gap G targeted for adjusting the size of the SB gap G is described as follows.

[0144] Table 1 shows two levels of SB gap G size for adjusting the size of the SB gap G. These two levels are determined based on the “local maximum peak value” or “local maximum peak position” of the magnetic flux density of the adjustment pole S1.

[0145] Table 2 shows four levels of SB gap G size for adjusting the size of the SB gap G. These four levels are determined based on the “local maximum peak value” or “local maximum peak position” of the magnetic flux density of the adjustment pole S1.

[0146] Table 1

[0147] Level A Level B SB A SB B

[0148] Table 2

[0149]

[0150] Table 1 can be used to adjust the size of the SB gap G by taking into account either the "local maximum peak value" or the "local maximum peak position" of the magnetic flux density of the adjustment pole S1 to account for changes in the characteristics of each individual magnet 71. On the other hand, Table 2 can be used to adjust the size of the SB gap G by taking into account both the "local maximum peak value" or the "local maximum peak position" of the magnetic flux density of the adjustment pole S1 to account for changes in the characteristics of each individual magnet 71.

[0151] Here, refer to Figure 18A and Figure 18B The relationship between the adjustment range of the SB gap G and the developer coating amount will be described. Figure 18A and Figure 18B As the level of the size of the SB gap G targeted for adjusting the size of the SB gap G, the two-level levels shown in Table 1 are used as an example.

[0152] like Figure 18A and Figure 18B As shown in , it is assumed that the lower limit value of the adjustment range of the SB gap G is “level A”, and it is assumed that the upper limit value of the adjustment range of the SB gap G is “level B”.

[0153] Figure 18A The relationship between the adjustment range of the SB gap G and the developer coating amount when the “local maximum peak value” of the magnetic flux density of the adjustment pole S1 is “level A” and the “local maximum peak position” of the magnetic flux density of the adjustment pole S1 is “level A” is illustrated.

[0154] Figure 18B The relationship between the adjustment range of the SB gap G and the developer coating amount when the "local maximum peak value" of the magnetic flux density of the adjustment pole S1 is "level B" and the "local maximum peak position" of the magnetic flux density of the adjustment pole S1 is "level B" is illustrated.

[0155] In the third exemplary embodiment, actual measured values ​​of the "local maximum peak value" and "local maximum peak position" of the magnetic flux density of the adjustment pole S1 are calculated for each individual magnet 71. Next, based on the calculated "local maximum peak value" and calculated "local maximum peak position" of the magnetic flux density of the adjustment pole S1, a level of the SB gap G size, which is targeted for adjusting the size of the SB gap G, is determined in advance. The determined level of the SB gap G size is then recorded on the developing sleeve 70.

[0156] Furthermore, in the third exemplary embodiment, the developing sleeve 70 on which the level of the size of the SB gap G is recorded is attached to the developing frame member 30. Then, the apparatus 100 acquires the level of the size of the SB gap G recorded on the developing sleeve 70 supported by the developing frame member 30. Then, the apparatus 100 adjusts the position at which the regulating blade 36 is to be fixed to the developing frame member 30 in such a manner that the size of the SB gap G falls within the adjustment range of the SB gap G corresponding to the acquired level of the size of the SB gap G, and fixes the regulating blade 36 to the developing frame member 30.

[0157] In the third exemplary embodiment described above, instead of recording information regarding the "local maximum peak value" or "local maximum peak position" of the magnetic flux density of the regulating pole S1 on the developing sleeve 70, only the level of the size of the SB gap G needs to be recorded on the developing sleeve 70. Therefore, in the third exemplary embodiment, the amount of information to be recorded on the developing sleeve 70 can be reduced compared to the first exemplary embodiment. The method of recording data on the developing sleeve 70 is not limited to a two-dimensional barcode, as long as the amount of information to be recorded on the developing sleeve 70 can be reduced. Specifically, numbers, characters, or symbols representing the level of the size of the SB gap G can be recorded directly on the developing sleeve 70, for example, by engraving, printing, or typing.

[0158] However, in the third exemplary embodiment, compared to the first exemplary embodiment, which determined the range of the SB gap G size by taking into account the actual measured value of the "local maximum peak value" or "local maximum peak position" of the magnetic flux density of the regulating pole S1, it is possible to maintain a variation in ΔM for each rank. Therefore, in the third exemplary embodiment, the degree to which the variation in the characteristics of the feedback magnet 71 contributes to the range of the SB gap G size becomes smaller than in the first exemplary embodiment. Therefore, if the effect of preventing or reducing the variation in the developer coating amount (ΔM) takes priority over reducing the amount of information to be recorded on the developing sleeve 70, the ranks used to rank the SB gap G sizes can be set more finely.

[0159] In the fourth exemplary embodiment, a more advantageous example for performing adjustment of the SB gap G with higher accuracy is described.

[0160] Causes of variations in the developer coating amount during driving of the developing device 3 include deviations in the outer diameter of the developing sleeve 70. Therefore, in the fourth exemplary embodiment, adjustment of the SB gap G is performed with higher accuracy by taking into account the straightness of the surface of the developing sleeve 70 (in other words, deviations in the outer diameter of the developing sleeve 70) in addition to variations in the characteristics of the individual magnets 71.

[0161] Since the sleeve forming the outer shell of the developing sleeve 70 is made of metal, secondary cutting processing is performed on the sleeve so that the flatness of the surface of the developing sleeve 70 can be measured with high accuracy, for example, ±15 μm or less. However, in the rotation state of the developing sleeve 70 in actual use, the flatness of the developing sleeve 70 of ±15 μm is grasped as if the outer diameter of the developing sleeve 70 significantly varies by ±15 μm. Therefore, in order to minimize the influence of the flatness of the surface of the developing sleeve 70 on the SB gap G while the developing sleeve 70 is rotating, it is effective to measure the SB gap G while the developing sleeve 70 is rotating.

[0162] Here, refer to Figure 19A 、 Figure 19B and Figure 19C The deviation of the outer diameter of the developing sleeve 70 will be described.

[0163] Figure 19A and Figure 19B Each of the diagrams is used to explain the deviation in the outer diameter of the developing sleeve 70 . Figure 19C 3 is a diagram illustrating the relationship between the deviation in the outer diameter of the developing sleeve 70 and the size of the SB gap G.

[0164] Consider things like Figure 19A The developing sleeve 70 having a deviation in the outer diameter of the developing sleeve 70 is rotated as shown in FIG. Figure 19B As shown in , the size of the SB gap G, which is targeted for adjusting the size of the SB gap G, changes with a portion corresponding to the deviation of the outer diameter of the developing sleeve 70 in one rotation cycle of the developing sleeve 70. Therefore, in order to reduce the influence of the deviation of the outer diameter of the developing sleeve 70, it is necessary to adjust the center value of the outer diameter of the developing sleeve 70 in such a manner that the size of the SB gap G falls within a predetermined range. Therefore, it is possible to consider factors such as Figure 19C The relationship between the deviation of the outer diameter of the developing sleeve 70 and the size of the SB gap G is shown in FIG.

[0165] Next, refer to Figure 20 Next, description will be given of a portion where a phase recognition portion of the developing sleeve 70 is provided. The phase recognition portion is provided to recognize the phase of the magnet 71 fixedly positioned inside the developing sleeve 70 (the phase of the developing sleeve 70).

[0166] like Figure 20As shown in , the phase identification portion is provided at a portion (70F) corresponding to the end portion in the longitudinal direction of the developing sleeve 70 (the end portion in the longitudinal direction of the shaft portion of the magnet). The deviation amount of the phase of the developing sleeve 70 is calculated based on data on the center value of the deviation, and the center value of the deviation is the deviation value of the closest position between the phase identification portion and the regulating blade 36. Then, the range of the size of the SB gap G aimed at adjusting the size of the SB gap G can be adjusted by offsetting the adjustment range of the SB gap G by a value corresponding to the calculated deviation amount of the phase of the developing sleeve 70. This makes it possible to adjust the size of the SB gap G while using the center value of the deviation of the outer diameter of the developing sleeve 70. As a result, the influence of the deviation of the outer diameter of the developing sleeve 70 can be reduced to half.

[0167] Furthermore, when adjusting the size of the SB gap G, in the case of recognizing only the phase of the developing sleeve 70 via, for example, a sensor (a camera or a laser device), the phase of the developing sleeve 70 may vary depending on the attachment state of the developing sleeve 70 to the developing frame member 30. Therefore, phase data regarding all deviations in the outer diameter of the developing sleeve 70 becomes necessary.

[0168] Therefore, consider the case where all the phase data on the deviation of the outer diameter of the developing sleeve 70 are recorded on the developing sleeve 70 by using a two-dimensional bar code. In this case, the device 100 reads the two-dimensional bar code to obtain all the phase data on the deviation of the outer diameter of the developing sleeve 70 from the developing sleeve 70, and calculates the offset from the center value. Then, the device 100 is able to feed back the offset to the center value of the size of the SB gap G with the goal of adjusting the size of the SB gap G. On the other hand, when adjusting the size of the SB gap G, with the phase of the developing sleeve 70 fixed to a predetermined position, the position of the developing sleeve 70 closest to the regulating blade 36 when adjusting the size of the SB gap G is fixed to a predetermined position. Therefore, when measuring the deviation of the outer diameter of the developing sleeve 70, the offset of the SB gap G to be adjusted can be calculated as the size of the SB gap G.

[0169] The present invention is not limited to the above-described exemplary embodiments, but can be modified in various ways (including organic combinations of the embodiments) based on the gist of the present invention, so that these modifications should not be excluded from the scope of the present invention.

[0170] While the exemplary embodiment described above has been described as an example in which the regulating pole S1 and the magnetic pole (drawing pole N1) for generating a magnetic field that draws the developer in the developing chamber 31 so that the developer is carried on the surface of the developing sleeve 70 are configured as separate magnetic poles, the exemplary embodiment is not limited to this example. A configuration in which a single magnetic pole performs both the functions of the regulating pole S1 and the functions of the drawing pole N1 can be employed. In such a configuration, the single magnetic pole generates a magnetic force in such a manner as to draw the developer in the developing chamber 31 while regulating the amount of developer passing through the SB gap G.

[0171] Furthermore, although in the above exemplary embodiments, Figure 1 As shown in FIG, the image forming apparatus 60 having a configuration in which the intermediate transfer belt 61 is used as the intermediate transfer member has been described as an example, but the exemplary embodiment is not limited thereto. The present invention can also be applied to an image forming apparatus having a configuration in which transfer is performed by bringing recording materials into direct contact with the photosensitive drums 1 in sequence.

[0172] Furthermore, although the developing device 3 has been described as a single unit in the above-described exemplary embodiments, the image forming unit 600 (see FIG. 1 ) including the developing device 3 may be configured as a single unit. Figure 1 Similar advantageous effects can also be obtained in the form of a process cartridge that is integrally formed with the developing device 3 and can be attached to and detached from the image forming apparatus 60. In addition, the present invention can also be applied to an image forming apparatus 60 including such a developing device 3 or a process cartridge, regardless of whether it is a monochrome machine or a color machine.

[0173] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A magnetic roller, the magnetic roller being non-rotatably and fixedly disposed inside a rotatable developer carrying member, the developer carrying member being used to transport and supply developer to a developing position, the magnetic roller comprising: a plurality of magnetic poles including a developing pole and a regulating pole, the developing pole being arranged opposite to the image bearing member in a developing position, and the regulating pole of the plurality of magnetic poles being arranged closest to a developer regulating member that regulates the amount of developer carried on the developer bearing member, a shaft configured to secure the plurality of magnetic poles; as well as Records Department, Information on the local maximum peak value of the magnetic flux density of the regulating pole and / or information on the local maximum peak position of the magnetic flux density of the regulating pole is recorded in the recording portion.

2. The magnetic roller according to claim 1, in, The recording portion is provided at the shaft.

3. The magnetic roller according to claim 1, in, Information on the local maximum peak value of the magnetic flux density of the regulating pole and / or information on the local maximum peak position of the magnetic flux density of the regulating pole is recorded at the recording portion using a barcode.

4. The magnetic roller according to claim 1, in, Information on the local maximum peak value of the magnetic flux density of the regulating pole and / or information on the local maximum peak position of the magnetic flux density of the regulating pole is recorded at the recording portion by engraving.

5. The magnetic roller according to claim 1, in, Information on the local maximum peak value of the magnetic flux density of the regulating pole and / or information on the local maximum peak position of the magnetic flux density of the regulating pole is recorded at the recording portion by printing.

6. The magnetic roller according to claim 1, in, The information about the local maximum peak value of the magnetic flux density of the regulating pole and / or the information about the local maximum peak position of the magnetic flux density of the regulating pole is a combination of information about the local maximum peak value of the magnetic flux density of the regulating pole at the end portion in the longitudinal direction of the magnetic roller, information about the local maximum peak value of the magnetic flux density of the regulating pole at the other end portion in the longitudinal direction of the magnetic roller, and information about the local maximum peak value of the magnetic flux density of the regulating pole at the central portion in the longitudinal direction of the magnetic roller, or a combination of information about the local maximum peak position of the magnetic flux density of the regulating pole at the end portion in the longitudinal direction of the magnetic roller, information about the local maximum peak position of the magnetic flux density of the regulating pole at the other end portion in the longitudinal direction of the magnetic roller, and information about the local maximum peak position of the magnetic flux density of the regulating pole at the central portion in the longitudinal direction of the magnetic roller.

7. The magnetic roller according to claim 1, in, Information on the local maximum peak value of the magnetic flux density of the regulating pole is recorded at the recording portion.

8. The magnetic roller according to claim 1, in, Information on the local maximum peak position of the magnetic flux density of the regulating pole is recorded at the recording portion.

9. The magnetic roller according to claim 1, in, Information on the local maximum peak value of the magnetic flux density of the regulating pole and information on the local maximum peak position of the magnetic flux density of the regulating pole are recorded at the recording portion.

10. A developer carrying member configured to convey a developer and supply the developer to a developing position, the developer carrying member having the magnetic roller defined in any one of claims 1 to 9 provided therein, the developer carrying member comprising: Rotatable sleeve, The plurality of magnetic poles are non-rotatably and fixedly arranged inside the rotatable sleeve.

11. A developing device having the developer carrying member defined in claim 10, the developing device comprising: a developing container configured to accommodate a developer; as well as a developer regulating member configured to regulate the amount of the developer carried on the developer carrying member, Among the plurality of magnetic poles, the regulating pole is arranged closest to the developer regulating member.

Images