JP2009047821A - Developer carrier, developing device, process cartridge, image forming apparatus, and color image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a developer carrier capable of preventing the occurrence of uneven shading in groove pitch and uneven shading in sleeve pitch and preventing the occurrence of pitch-like horizontal black line and pitch-like vertical black line even during its use for ages, and to provide a developing device, a process cartridge, and an image forming apparatus with this developer carrier. <P>SOLUTION: The developer carrier has a crisscross pattern-like groove formed to let a plurality of grooves 141a storing a hollow body 132 extended in the direction inclined for the direction of rotation thrust cross a plurality of grooves 141b extended in the direction inclined onto the opposite side to the direction of thrust. A linear material 65 is made to collide against a part 141c surrounded by the grooves 141a and 141b on an external surface to make it rough, and elliptical recesses are formed at random. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a developer carrying member, a developing device, a process cartridge, and an image forming apparatus used in, for example, a copying machine, a facsimile machine, a printer, and the like, and more specifically, a developer carried on a hollow member, a photosensitive member and a hollow member. The present invention relates to a developer carrying member and a developing device which are transported to a developing region facing a body with a gap and develop a latent electrostatic image on the photosensitive member to form a toner image. The present invention also relates to a process cartridge and an image forming apparatus having such a developing device.

  Recent copiers, printers, and the like have very high demands for high image quality and high stability. In order to satisfy these requirements, the temporal stability and uniformity of the developer amount on the developer carrying member are important. Conventionally, a hollow body in which irregularities are formed on the surface by sandblasting and a hollow body in which a plurality of grooves extending in parallel to the rotation axis of the developer carrying body are formed on the surface are generally used.

  In the hollow body provided with unevenness using sandblasting, if the unevenness amount is small, the developer conveying ability decreases. Depending on the specific conditions of the unevenness, the unevenness may be gradually scraped by the developer due to use over time, the developer conveying ability may be reduced, and an abnormal image (density reduction) may occur. Further, if the unevenness amount is increased in order to increase the developer conveying ability, the hollow body may be deformed during processing, and an abnormal image (sleeve pitch unevenness) may occur.

  A hollow body in which a plurality of grooves extending in parallel to the rotation axis of the developer carrying member is formed on the surface has a larger developer conveying ability than a hollow body provided with unevenness using sandblasting, and a developer that has been used over time. Little decrease in transfer capacity. However, depending on the specific conditions of the grooves extending in parallel, each part of each developer transport groove parallel to the developer regulating member passes over the regulating member at the same moment, so an abnormal image (groove pitch) by the shock jitter (Shading unevenness) may occur. There is also a problem that the stress applied to the developer is large. Further, if the shape of each groove is not uniform, the pumping amount may be uneven and an abnormal image (sleeve pitch unevenness) may occur.

In order to solve such conventional technical problems, hollow bodies described in Patent Documents 1 to 4 have been proposed. These hollow bodies are hollow bodies having iris-like grooves formed on the surface.
JP 2003-316146 A JP 2003-316146 A JP 2000-242073 A Japanese Patent Laid-Open No. 07-13410

  However, depending on the specific conditions of the iris-shaped groove, a portion having a high development density extending in the thrust direction (longitudinal direction) is generated at a predetermined pitch in the circumferential direction (rotation direction) of the hollow body, resulting in a horizontal black stripe shape. An abnormal image that can be seen (hereinafter referred to as a pitch-like horizontal black stripe) may occur. In addition, depending on the specific conditions of the iris-shaped groove, a portion having a high development density extending in the circumferential direction (rotation direction) is generated at a predetermined pitch in the thrust direction (longitudinal direction) of the hollow body, resulting in a vertical black stripe shape. An abnormal image that can be seen (hereinafter referred to as a pitch-like vertical black stripe) may occur.

  The present invention has been made in view of the above problems, and suppresses the occurrence of abnormal images due to the occurrence of groove pitch shading unevenness and sleeve pitch shading unevenness, and the above-described pitch-like horizontal black lines and pitch-like vertical black stripes. A first object is to provide a developer carrier capable of suppressing the occurrence of abnormal images due to occurrence even over time, and a developing device, a process cartridge, and an image forming apparatus provided with such a developer carrier. The second purpose is to provide it.

  In the first aspect of the invention, the outer surface includes a plurality of grooves extending in a direction inclined with respect to the rotational thrust direction and a plurality of grooves extending in a direction inclined opposite to the rotational thrust direction. A hollow body having an iris-shaped groove formed as described above and a portion surrounded by the iris-shaped groove, and a magnetic field generating means for adsorbing the developer on the outer surface by a magnetic force inside the hollow body. In the developer carrier, a portion surrounded by the iris-shaped groove on the outer surface of the hollow body is randomly provided with a recess formed by a roughening treatment. is there.

  According to a second aspect of the present invention, in the first aspect of the present invention, a large number of elliptical recesses are randomly provided in a portion surrounded by the iris-shaped groove on the outer surface of the hollow body. It is characterized by.

  In the invention described in claim 3, in the invention described in claim 1 or 2, a large number of elliptical recesses in the portion surrounded by the iris-shaped groove on the outer surface of the hollow body collided randomly. It is formed of a short wire rod.

  According to a fourth aspect of the present invention, there is provided a developing device comprising the developer carrying member according to any one of the first to third aspects.

  The invention described in claim 5 is the invention described in claim 4, wherein the developer contains toner and a magnetic carrier, and the average particle diameter of the magnetic carrier is 20 μm or more and 50 μm or less. It is in the range.

  The invention described in claim 6 is a process cartridge including the developing device according to claim 4 or 5.

  According to a seventh aspect of the present invention, there is provided an image forming apparatus comprising the process cartridge according to the sixth aspect.

  According to an eighth aspect of the present invention, there is provided a color image forming apparatus comprising a plurality of process cartridges according to the sixth aspect.

  According to the developer carrier of claim 1, the plurality of grooves extending in the direction inclined with respect to the rotational thrust direction and the plurality of grooves extending in the direction inclined opposite to the rotational thrust direction. And the portion surrounded by the iris-shaped groove is formed with a recess by the roughening treatment, so that the developer conveying ability of the portion other than the groove is As a result, the difference in the conveying ability of the developer other than the groove and the groove is reduced, thereby suppressing the occurrence of groove pitch unevenness and sleeve pitch unevenness, as well as pitch horizontal black lines and pitch vertical black lines. Occurrence can be suppressed even in aged use.

  According to the developer-carrying member according to claim 2, since a number of oval-shaped dents are randomly provided in the portion surrounded by the iris-shaped groove on the outer surface of the hollow body, the outer surface of the hollow body is maintained over time. In particular, a decrease in developer conveying force in the portion surrounded by the iris-shaped groove is suppressed well, and pitch-like horizontal black lines and pitch-like vertical black lines can be suppressed.

  According to the developer carrying member of the third aspect, since the elliptical dent is formed by the short wire rod material that randomly collides with the outer surface of the hollow body, the shaft core of the hollow body is curved. And the inner and outer diameters can be prevented from changing and the cross-sectional shape can be prevented from becoming elliptical, and abnormal images (sleeve pitch unevenness) can be suppressed.

  According to the developing device of the fourth aspect, the developer carrying member according to any one of the first to third aspects is provided. Therefore, the groove pitch density unevenness and the sleeve pitch density unevenness are reduced. Generation | occurrence | production can be suppressed and generation | occurrence | production of a pitch-like horizontal black stripe and a pitch-like vertical black stripe can be suppressed also in aged use.

  According to the developing device of claim 5, since the average particle diameter of the magnetic carrier contained in the developer is in the range of 20 μm or more and 50 μm or less, an excellent image with excellent granularity and less unevenness is obtained. be able to.

  According to the process cartridge of the sixth aspect, since the developing device according to any one of the fourth to sixth aspects is included, an excellent image having excellent granularity and no image unevenness is obtained. be able to.

  According to the image forming apparatus of the seventh aspect, since the process cartridge according to the sixth aspect is provided, an excellent image having excellent granularity and no image unevenness can be obtained.

  According to the color image forming apparatus of the eighth aspect, since the plurality of process cartridges according to the sixth aspect are provided, an excellent color image having excellent granularity and no image unevenness can be obtained.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory diagram viewed from the front of the configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of a process cartridge according to an embodiment of the present invention of the image forming apparatus shown in FIG. 3 is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a perspective view of a hollow body as a developer carrier of the developing device shown in FIG. FIG. 5 is a cross-sectional view of the magnetic carrier of the developer of the developing device shown in FIG. FIG. 6 is an explanatory diagram showing an enlarged outer surface of the hollow body shown in FIG. FIG. 7 is a perspective view showing an outline of the configuration of a surface treatment apparatus that performs a roughening treatment on the outer surface of the hollow body shown in FIG. 4. 8 is a cross-sectional view taken along the line II-II in FIG. FIG. 9 is a perspective view of magnetic abrasive grains used in the surface treatment apparatus shown in FIG. FIG. 10 is a cross-sectional view schematically showing a state of growing on the outer surface of the hollow body shown in FIG. FIG. 11 is a cross-sectional view schematically showing a state of growing on the outer surface of a hollow body subjected to conventional sandblasting. 12 is a cross-sectional view of a groove provided in the hollow body shown in FIG.

  The image forming apparatus 101 prints an image of each color of yellow (Y), magenta (M), cyan (C), and black (K), that is, a color image, on a recording sheet 107 (see FIG. 1). ) To form. Note that units corresponding to yellow, magenta, cyan, and black colors are denoted by Y, M, C, and K at the end of the reference numerals.

  As shown in FIG. 1, the image forming apparatus 101 includes an apparatus main body 102, a paper feed unit 103, a registration roller pair 110, a transfer unit 104, a fixing unit 105, and a plurality of laser writing units 122Y, 122M, and 122C. , 122K and a plurality of process cartridges 106Y, 106M, 106C, 106K.

  The apparatus main body 102 is formed in a box shape, for example, and is installed on a floor or the like. The apparatus main body 102 includes a paper feed unit 103, a registration roller pair 110, a transfer unit 104, a fixing unit 105, a plurality of laser writing units 122Y, 122M, 122C, and 122K, and a plurality of process cartridges 106Y, 106M, and 106C. , 106K.

  A plurality of paper feed units 103 are provided in the lower part of the apparatus main body 102. The paper feed unit 103 includes a paper feed cassette 123 that can accommodate the above-described recording paper 107 in a stacked manner and can be taken in and out of the apparatus main body 102, and a paper feed roller 124. The paper feed roller 124 is pressed against the uppermost recording paper 107 in the paper feed cassette 123. The paper feed roller 124 is used to transfer the above-described uppermost recording paper 107 between a transfer belt 129 (to be described later) of the transfer unit 104 and a photosensitive drum 108 of the developing device 113 (to be described later) of the process cartridges 106Y, 106M, 106C, and 106K. Send it in between.

  The registration roller pair 110 is provided in a conveyance path of the recording paper 107 conveyed from the paper supply unit 103 to the transfer unit 104, and includes a pair of rollers 110a and 110b. The registration roller pair 110 sandwiches the recording paper 107 between the pair of rollers 110a and 110b, and the transfer unit 104 and the process cartridges 106Y, 106M, 106C, and 106K at a timing at which toner images can be superimposed on the sandwiched recording paper 107. Send between.

  The transfer unit 104 is provided above the paper feed unit 103. The transfer unit 104 includes a driving roller 127, a driven roller 128, a conveyance belt 129, and transfer rollers 130Y, 130M, 130C, and 130K. The drive roller 127 is disposed on the downstream side in the conveyance direction of the recording paper 107 and is driven to rotate by a motor or the like as a drive source. The driven roller 128 is rotatably supported by the apparatus main body 102 and is disposed on the upstream side in the conveyance direction of the recording paper 107. The conveyor belt 129 is formed in an endless annular shape and is stretched over both the driving roller 127 and the driven roller 128 described above. The transport belt 129 circulates (endless travel) counterclockwise around the drive roller 127 and the driven roller 128 described above by driving the drive roller 127 to rotate.

  The transfer rollers 130Y, 130M, 130C, and 130K sandwich the conveyance belt 129 and the recording paper 107 on the conveyance belt 129 between the photosensitive drums 108 of the process cartridges 106Y, 106M, 106C, and 106K, respectively. In the transfer unit 104, the transfer rollers 130Y, 130M, 130C, and 130K press the recording paper 107 fed from the paper supply unit 103 against the outer surface of the photosensitive drum 108 of each process cartridge 106Y, 106M, 106C, and 106K. The toner image on the photosensitive drum 108 is transferred to the recording paper 107. The transfer unit 104 sends the recording paper 107 onto which the toner image is transferred toward the fixing unit 105.

  The fixing unit 105 is provided downstream of the transfer unit 104 in the conveyance direction of the recording paper 107, and includes a pair of rollers 105a and 105b that sandwich the recording paper 107 therebetween. The fixing unit 105 presses and heats the recording paper 107 sent out from the transfer unit 104 between a pair of rollers 105a and 105b, thereby recording the toner image transferred from the photosensitive drum 108 onto the recording paper 107. Fix to paper 107.

  The laser writing units 122Y, 122M, 122C, and 122K are attached to the upper part of the apparatus main body 102, respectively. The laser writing units 122Y, 122M, 122C, and 122K correspond to one process cartridge 106Y, 106M, 106C, and 106K, respectively. The laser writing units 122Y, 122M, 122C, and 122K irradiate laser beams onto the outer surface of the photosensitive drum 108 that is uniformly charged by a later-described charging roller 109 of the process cartridges 106Y, 106M, 106C, and 106K. An electrostatic latent image is formed.

  The process cartridges 106Y, 106M, 106C, and 106K are provided between the transfer unit 104 and the laser writing units 122Y, 122M, 122C, and 122K, respectively. The process cartridges 106Y, 106M, 106C, and 106K are detachable from the apparatus main body 102. The process cartridges 106Y, 106M, 106C, and 106K are arranged side by side along the conveyance direction of the recording paper 107.

  As shown in FIG. 2, the process cartridges 106Y, 106M, 106C, and 106K include a cartridge case 111, a charging roller 109 as a charging device, a photosensitive drum 108 as an electrostatic latent image carrier, and a cleaning device. A cleaning blade 112 and a developing device 113 are provided. Therefore, the image forming apparatus 101 includes at least a charging roller 109, a photosensitive drum 108, a cleaning blade 112, and a developing device 113.

  The cartridge case 111 is detachably attached to the apparatus main body 102 and accommodates a charging roller 109, a photosensitive drum 108, a cleaning blade 112, and a developing device 113. The charging roller 109 uniformly charges the outer surface of the photosensitive drum 108. The photosensitive drum 108 is disposed with a space from a developer carrier 115 (described later) of the developing device 113. The photosensitive drum 108 is formed in a columnar shape or a cylindrical shape that is rotatable around an axis. An electrostatic latent image is formed on the outer surface of the photosensitive drum 108 by the corresponding laser writing units 122Y, 122M, 122C, and 122K. The photosensitive drum 108 is developed by adsorbing toner onto an electrostatic latent image formed on and carried on the outer surface, and the toner image thus obtained is transferred to a recording paper 107 positioned between the conveyance belt 129. To do. The cleaning blade 112 removes the transfer residual toner remaining on the outer surface of the photosensitive drum 108 after the toner image is transferred to the recording paper 107.

  As shown in FIG. 2, the developing device 113 includes at least a developer supply unit 114, a case 125, a developer carrier 115, and a regulating blade 116 as a regulating member.

  The developer supply unit 114 includes a storage tank 117 and a pair of stirring screws 118 as stirring members. The storage tank 117 is formed in a box shape having a length substantially equal to that of the photosensitive drum 108. Further, a partition wall 119 extending along the longitudinal direction of the storage tank 117 is provided in the storage tank 117. The partition wall 119 partitions the storage tank 117 into a first space 120 and a second space 121. Moreover, both ends of the first space 120 and the second space 121 communicate with each other.

  The storage tank 117 stores the developer 126 in both the first space 120 and the second space 121. The developer 126 includes toner and a magnetic carrier (also called magnetic powder, whose cross section is shown in FIG. 5) 135. The toner is appropriately supplied to one end of the first space 120 on the side of the first space 120 and the second space 121 which is away from the developer carrier 115. The toner is spherical fine particles produced by an emulsion polymerization method or a suspension polymerization method. The toner may be obtained by pulverizing a lump composed of a synthetic resin in which various dyes or pigments are mixed and dispersed. The average particle diameter of the toner is 3 μm or more and 7 μm or less. The toner may be formed by pulverization or the like.

  The magnetic carrier 135 is accommodated in both the first space 120 and the second space 121. The average particle diameter of the magnetic carrier 135 is 20 μm or more and 50 μm or less. As shown in FIG. 5, the magnetic carrier 135 includes a core material 136, a resin coat film 137 covering the outer surface of the core material 136, and alumina particles 138 dispersed in the resin coat film 137. .

  The core 136 is made of ferrite as a magnetic material and is formed in a spherical shape. The resin coat film 137 covers the entire outer surface of the core material 136. The resin coat film 137 contains a resin component obtained by crosslinking a thermoplastic resin such as acrylic and a melamine resin, and a charge adjusting agent. This resin coat film 137 has elasticity and strong adhesive force. The alumina particles 138 are formed in a spherical shape whose outer diameter is larger than the thickness of the resin coat film 137. The alumina particles 138 are held with a strong adhesive force of the resin coat film 137. The alumina particles 138 protrude from the resin coat film 137 to the outer peripheral side of the magnetic carrier 135.

  The stirring screw 118 is accommodated in each of the first space 120 and the second space 121. The longitudinal direction of the stirring screw 118 is parallel to the longitudinal directions of the storage tank 117, the developer carrier 115 and the photosensitive drum 108. The agitating screw 118 is provided so as to be rotatable around an axis, and rotates around the axis to agitate the toner and the magnetic carrier 135 and convey the developer along the axis.

  In the illustrated example, the agitation screw 118 in the first space 120 conveys the developer 126 from one end to the other end. The agitation screw 118 in the second space 121 conveys the developer 126 from the other end toward the one end.

  According to the above-described configuration, the developer supply unit 114 conveys the toner supplied to one end of the first space 120 to the other end while stirring with the magnetic carrier 135, and the second supply from the other end. It is conveyed to the other end of the space 121. The developer supply unit 114 agitates the toner and the magnetic carrier 135 in the second space 121 and supplies the toner and the magnetic carrier 135 to the outer surface of the developer carrier 115 while transporting the toner in the axial direction.

  The case 125 is formed in a box shape, is attached to the storage tank 117 of the developer supply unit 114 described above, and covers the developer carrier 115 and the like together with the storage tank 117. In addition, an opening 125 a is provided in a portion of the case 125 that faces the photosensitive drum 108.

  The developer carrier 115 is formed in a columnar shape, and is provided between the second space 121 and the photosensitive drum 108 and in the vicinity of the opening 125a described above. The developer carrier 115 is parallel to both the photosensitive drum 108 and the storage tank 117. The developer carrier 115 is disposed with a gap from the photosensitive drum 108. The developer carrier 115 is disposed with a gap from the photosensitive drum 108. The space between the developer carrying member 115 and the photosensitive drum 108 forms a developing region 131 in which the toner of the developer 126 is attracted to the photosensitive drum 108 and the electrostatic latent image is developed to obtain a toner image. Yes. In the development region 131, the developer carrier 115 and the photosensitive drum 108 face each other.

  As shown in FIGS. 2 and 3, the developer carrier 115 includes a cored bar 134, a cylindrical magnetic field generating means (also referred to as a magnet body) 133, and a cylindrical hollow body 132. The core metal 134 is arranged in parallel with the longitudinal direction of the photosensitive drum 108 in the longitudinal direction, and is fixed to the case 125 without rotating.

  The magnetic field generating means 133 is made of a magnetic material, is formed in a cylindrical shape, and a plurality of fixed magnetic poles (not shown) are attached. The magnetic field generating means 133 is fixed to the outer periphery of the cored bar 134 without rotating around the axis.

  The fixed magnetic pole is a long and rod-shaped magnet, and is attached to the magnetic field generating means 133. The fixed magnetic pole extends along the longitudinal direction of the magnetic field generating means 133, that is, the developer carrier 115, and is provided over the entire length of the magnetic field generating means 133. The magnetic field generating means 133 having the above-described configuration is accommodated (enclosed) in the hollow body 132.

  One fixed magnetic pole is opposed to the agitating screw 118 described above. The one fixed magnetic pole serves as a pumping magnetic pole, and generates a magnetic force on the outer surface of the hollow body 132, that is, the developer carrier 115, so that the developer 126 in the second space 121 of the storage tank 117 is hollowed out. Adsorb to the outer surface of 132.

  The other fixed magnetic pole is opposed to the photosensitive drum 108 described above. The fixed magnetic pole forms a developing magnetic pole, and generates a magnetic force on the outer surface of the hollow body 132, that is, the developer carrier 115, thereby forming a magnetic field between the hollow body 132 and the photosensitive drum 108. The fixed magnetic pole forms a magnetic brush by the magnetic field, so that the toner of the developer 126 adsorbed on the outer surface of the hollow body 132 is transferred to the photosensitive drum 108.

  At least one fixed magnetic pole is provided between the pumping magnetic pole and the developing magnetic pole. The at least one fixed magnetic pole generates a magnetic force on the outer surface of the hollow body 132, that is, the developer carrier 115, conveys the developer 126 before development toward the photosensitive drum 108, and develops the developed developer. The agent 126 is conveyed from the photosensitive drum 108 into the storage tank 117.

  When the developer 126 adsorbs the developer 126 to the outer surface of the hollow body 132, the magnetic carrier 135 of the developer 126 is overlapped along the magnetic force lines generated by the fixed magnetic pole, and the fixed magnetic pole is placed on the outer surface of the hollow body 132. To stand up. In this way, a state in which a plurality of magnetic carriers 135 are stacked on the outer surface of the hollow body 132 along the lines of magnetic force is called standing on the outer surface of the hollow body 132. Then, the above-described toner is adsorbed to the magnetic carrier 135 that is raised. In other words, the hollow body 132 adsorbs the developer 126 to the outer surface by the magnetic force of the magnetic field generating means 133.

  As shown in FIG. 4, the hollow body 132 is formed in a cylindrical shape. The hollow body 132 accommodates the magnetic field generation means 133 inside and is provided to be rotatable around the axis. The hollow body 132 is rotated so that the inner peripheral surface thereof is sequentially opposed to the fixed magnetic pole. The hollow body 132 is made of a nonmagnetic material such as aluminum, an aluminum alloy, or stainless steel (SUS).

  Aluminum alloys are excellent in terms of workability and lightness. When an aluminum alloy is used, it is preferable to use A6063, A5056, and A3003. When using SUS, it is preferable to use SUS303, SUS304, and SUS316.

  The outer diameter of the hollow body 132 is desirably about 17 mm to 18 mm. The length of the hollow body 132 in the axial (axial core) direction is desirably about 300 mm to 350 mm. The surface roughness of the outer surface of the hollow body 132 is gradually increased (roughened) from the central portion in the axial direction of the hollow body 132 toward both ends.

  An iris-shaped groove is formed on the surface of the hollow body 132. FIG. 6 shows an enlarged perspective view of the groove on the surface of the hollow body 132. As shown in FIG. 6, the iris-shaped groove intersects with a plurality of grooves 141 a inclined with respect to the rotation axis direction (rotational thrust direction) of the developer carrier 115 and a plurality of grooves 141 b inclined on the opposite side. Is formed. In addition, the angle of inclination in the former plurality of grooves 141a and the angle of inclination in the latter plurality of grooves 141b are not necessarily the same.

  Further, a portion 141c (a portion where no iris-shaped groove is formed) 141c surrounded by the iris-shaped groove on the outer surface of the hollow body 132 is roughened by the surface treatment apparatus 1 described later, and a number of elliptical depressions are formed. Is provided. Note that the roughening of the portion 141c surrounded by the iris-shaped groove on the outer surface is not limited to the surface treatment apparatus 1, and may be performed by a known sandblast or the like.

  A regulating blade (also referred to as a regulating member or a developing doctor) 116 is provided at an end portion of the developing device 113 near the photosensitive drum 108. The regulating blade 116 is attached to the case 125 described above with a space from the outer surface of the hollow body 132. The regulating blade 116 scrapes off the developer 126 on the outer surface of the hollow body 132 exceeding a desired thickness into the storage tank 117, and the developer 126 on the outer surface of the hollow body 132 conveyed to the developing region 131. To the desired thickness.

  In the developing device 113 configured as described above, the developer and the magnetic carrier 135 are sufficiently stirred by the developer supply unit 114, and the stirred developer 126 is adsorbed to the outer surface of the hollow body 132 by the fixed magnetic pole. Then, the developing device 113 conveys the developer 126 adsorbed by the plurality of fixed magnetic poles toward the developing region 131 as the hollow body 132 rotates. The developing device 113 causes the photosensitive drum 108 to adsorb the developer 126 having a desired thickness by the regulating blade 116. Thus, the developing device 113 carries the developer 126 on the developer carrying member 115, transports it to the developing region 131, develops the electrostatic latent image on the photosensitive drum 108, and forms a toner image.

  Then, the developing device 113 causes the developed developer 126 to be released toward the storage tank 117. Further, the developed developer 126 stored in the storage tank 117 is sufficiently stirred again with the other developer 126 in the second space 121, and the electrostatic latent image on the photosensitive drum 108 is recovered. Used for development.

  The image forming apparatus 101 having the above-described configuration forms an image on the recording paper 107 as described below. First, the image forming apparatus 101 rotates the photosensitive drum 108 and uniformly charges the outer surface of the photosensitive drum 108 by the charging roller 109. Laser light is irradiated on the outer surface of the photosensitive drum 108 to form an electrostatic latent image on the outer surface of the photosensitive drum 108. When the electrostatic latent image is positioned in the development area 131, the developer 126 adsorbed on the outer surface of the hollow body 132 of the developing device 113 is adsorbed on the outer surface of the photosensitive drum 108, and the electrostatic latent image is developed. Then, a toner image is formed on the outer surface of the photosensitive drum 108.

  In the image forming apparatus 101, the recording sheet 107 conveyed by the sheet feeding roller 124 of the sheet feeding unit 103 is transferred to the photosensitive drum 108 of the process cartridges 106Y, 106M, 106C, and 106K and the conveying belt 129 of the transfer unit 104. The toner image formed on the outer surface of the photosensitive drum 108 is transferred to the recording paper 107. The image forming apparatus 101 uses a fixing unit 105 to fix the toner image on the recording paper 107. Thus, the image forming apparatus 101 forms a color image on the recording paper 107.

  Next, a method for roughening the hollow body 132 will be described. The hollow body 132 described above is roughened on the outer surface by the surface treatment apparatus 1 shown in FIGS. 7 and 8 with the hollow body 132 as a workpiece 2.

  As shown in FIGS. 7 and 8, the surface treatment apparatus 1 includes a base 3, a fixed holding unit 4, an electromagnetic coil moving unit 5, a moving holding unit 6, a moving chuck unit 7, an electromagnetic coil 8, The storage tank 9, the collection | recovery part 10, the cooling part 11, the linear encoder 75, and the control apparatus 76 (shown in FIG. 8) are provided.

  The base 3 is formed in a flat plate shape and is installed on a factory floor or table. The upper surface of the base 3 is kept parallel to the horizontal direction. The planar shape of the base 3 is formed in a rectangular shape.

  The fixed holding portion 4 includes a plurality of support columns 12 erected from one end in the longitudinal direction of the base 3 (hereinafter, indicated by an arrow X), a holding base 13, a standing bracket 14, a cylindrical holding member 15, and a holding member. And a chuck 16.

  The holding base 13 is formed in a flat plate shape and is attached to the upper end of the support column 12. The standing bracket 14 is formed in a flat plate shape and stands from the holding base 13. The cylindrical holding member 15 is formed in a cylindrical shape, and is attached to the standing bracket 14 and the holding base 13. The cylindrical holding member 15 is disposed closer to the center of the base 3 than the upright bracket 14 in a state in which the axis is parallel to both the horizontal direction and the arrow X. The cylindrical holding member 15 accommodates flange members 51b, 51c, 51d (that is, one end portion 9a), which will be described later, attached to one end portion 9a, which will be described later, of the storage tank 9.

  The holding chuck 16 is disposed in the vicinity of the above-described cylindrical holding member 15, that is, the holding base 13, and is attached to the above-described base 3. The holding chuck 16 chucks the storage tank 9 in which the one end 9 a is stored in the cylindrical holding member 15, and holds the one end 9 a of the storage tank 9. The fixed holding portion 4 having the above-described configuration holds the one end portion 9 a of the storage tank 9.

  The electromagnetic coil moving unit 5 includes a pair of linear guides 17, an electromagnetic coil holding base 18, and an electromagnetic coil moving actuator 19. The linear guide 17 includes a rail 20 and a slider 21. The rail 20 is installed on the base 3. The rail 20 is formed in a straight line, and its longitudinal direction is arranged in parallel to the longitudinal direction of the base 3, that is, the arrow X. The slider 21 is supported by the rail 20 so as to be movable along the longitudinal direction of the rail 20, that is, along the arrow X. In the pair of linear guides 17, the rails 20 are arranged at intervals from each other along the width direction of the base 3 (hereinafter, indicated by an arrow Y). Of course, the arrow X and the arrow Y are orthogonal to each other and parallel to the horizontal direction.

  The electromagnetic coil holding base 18 is formed in a flat plate shape and is mounted on the slider 21 described above. The upper surface of the electromagnetic coil holding base 18 is arranged in parallel with the horizontal direction. The electromagnetic coil holding base 18 installs the electromagnetic coil 8 on the surface. The electromagnetic coil moving actuator 19 is attached to the base 3 and slides the electromagnetic coil holding base 18 along the arrow X. The above-described electromagnetic coil moving unit 5 slides the electromagnetic coil holding base 18, that is, the electromagnetic coil 8 along the arrow Y by the electromagnetic coil moving actuator 19. Moreover, the moving speed of the electromagnetic coil 8 by the electromagnetic coil moving part 5 can be changed between 0 mm / second and 300 mm / second. Furthermore, the moving range of the electromagnetic coil 8 of the electromagnetic coil moving part 5 is about 600 mm.

  The movable holding unit 6 includes a pair of linear guides 22, a holding base 23, a first actuator 24, a second actuator 25, a moving base 26, a bearing rotating unit 27, and a holding chuck 28. .

  The linear guide 22 includes a rail 29 and a slider 30. The rail 29 is installed on the base 3. The rail 29 is formed in a straight line, and its longitudinal direction is arranged in parallel with the arrow X, that is, the longitudinal direction of the base 3. The slider 30 is supported by the rail 29 so as to be movable along the longitudinal direction of the rail 29, that is, along the arrow X. In the pair of linear guides 22, rails 29 are arranged at intervals along the arrow Y, that is, the width direction of the base 3.

  The holding base 23 is formed in a flat plate shape and is mounted on the slider 30 described above. The upper surface of the holding base 23 is arranged in parallel with the horizontal direction. The first actuator 24 is attached to the base 3 and slides the holding base 23 described above along the arrow X.

  The second actuator 25 is attached to the holding base 23 and slides the moving base 26 along the arrow Y. The moving base 26 is formed in a flat plate shape, and its upper surface is arranged in parallel with the horizontal direction.

  The bearing rotating unit 27 includes a pair of bearings 31, a hollow holding member 32 as a core shaft, a driving motor 33 as a rotating means, and a chuck cylinder 34. The pair of bearings 31 are arranged on the moving base 26 while being spaced apart from each other along the arrow X. The hollow holding member 32 is made of a magnetic material, is formed in a cylindrical shape, and is supported by the above-described bearing 31 so as to be rotatable around the axis. The hollow holding member 32 has its axis arranged in parallel with the arrow X described above, that is, the axis of the cylindrical holding member 15 of the fixed holding unit 4. The hollow holding member 32 is shaped so as to protrude from the moving base 26 toward the fixed holding portion 4 so that the one end 32 a is located in the storage tank 9, and the other end 32 c is located on the moving base 26. Arranged in the state. The hollow holding member 32 is passed through the cylindrical workpiece 2 as shown in FIG. A pulley 35 is fixed to the other end portion 32 c of the hollow holding member 32 positioned on the moving base 26. The pulley 35 is disposed coaxially with the hollow holding member 32.

  The drive motor 33 is installed on the moving base 26, and a pulley 36 is attached to the output shaft thereof. The axis of the output shaft of the drive motor 33 is parallel to the arrow X. An endless timing belt 37 is wound around the pulleys 35 and 36 described above. The drive motor 33 rotates the hollow holding member 32 around the axis. The drive motor 33 rotates the hollow holding member 32 around the axis to rotate the workpiece 2 around the axis of the hollow holding member 32 parallel to the longitudinal direction of the storage tank 9.

  The chuck cylinder 34 includes a cylinder body 38 installed on the moving base 26 and a chuck shaft 39 slidably provided on the cylinder body 38. The chuck shaft 39 is formed in a cylindrical shape, and its longitudinal direction is arranged in parallel with the arrow X. The chuck shaft 39 is accommodated in the hollow holding member 32 and is disposed coaxially with the hollow holding member 32. A plurality of pairs of chuck claws 40 are attached to the chuck shaft 39.

  The pair of chuck claws 40 are attached to the chuck shaft 39 so as to protrude from the outer peripheral surface of the chuck shaft 39 in the outer peripheral direction of the chuck shaft 39. Further, the chuck pawl 40 can protrude from the outer peripheral surface of the hollow holding member 32 toward the outer periphery of the hollow holding member 32. The chuck claws 40 are provided so that the amount of protrusion from the chuck shaft 39 and the hollow holding member 32 can be changed. The plurality of pairs of chuck claws 40 are arranged at intervals along the longitudinal direction of the chuck shaft 39, that is, the arrow X. When the chuck shaft 39 of the chuck cylinder 34 is reduced in the direction approaching the cylinder body 38, the amount of protrusion of the pair of chuck claws 40 from the chuck shaft 39 and the hollow holding member 32 increases.

  In the chuck cylinder 34 described above, when the chuck shaft 39 is reduced to the cylinder body 38, the chuck pawl 40 protrudes further toward the outer periphery of the chuck shaft 39, and the chuck pawl 40 is attached to the outer periphery of the hollow holding member 32. The chuck shaft 39, the hollow holding member 32, and the workpiece 2 are fixed by pressing against the inner peripheral surface of the workpiece 2. That is, the surface to be roughened on the outer surface of the workpiece 2 is held exposed. At this time, of course, the chuck shaft 39, the hollow holding member 32, the workpiece 2, and the later-described cylindrical member 50, that is, the storage tank 9 are coaxial.

  The chuck cylinder 34 and the chuck pawl 40 described above hold the workpiece 2 so as to be coaxial with the hollow holding member 32 and the storage tank 9. That is, the chuck cylinder 34 and the chuck pawl 40 expose and hold the surface of the processing object 2 to be roughened on the outer surface of the processing object 2 at the center of the storage tank 9. The chuck cylinder 34, the chuck pawl 40, and the hollow holding member 32 described above constitute holding means.

  The holding chuck 28 is installed on the moving base 26 described above. The holding chuck 28 chucks a flange member 51a (described later) attached to the other end 9b of the storage tank 9, and holds the other end 9b of the storage tank 9. The holding chuck 28 restricts the storage tank 9 from rotating about its axis.

  The movement holding unit 6 having the above-described configuration moves the holding chuck 28, the hollow holding member 32, and the like along the arrows X and Y orthogonal to each other by the actuators 24 and 25. That is, the movement holding unit 6 moves the storage tank 9 held by the holding chuck 28 along the arrows X and Y.

  The moving chuck unit 7 includes a holding base 41, a linear guide 42, and a holding chuck 43. The holding base 41 is fixed to an end portion of the linear guide 22 near the fixed holding portion 4 of the rail 29. The holding base 41 is formed in a flat plate shape, and its upper surface is arranged in parallel with the horizontal direction.

  The linear guide 42 includes a rail 44 and a slider 45. The rail 44 is installed on the holding base 41. The rail 44 is formed in a straight line, and its longitudinal direction is arranged in parallel with the arrow Y, that is, the width direction of the base 3. The slider 45 is supported by the rail 44 so as to be movable along the longitudinal direction of the rail 44, that is, along the arrow Y.

  The holding chuck 43 is installed on the slider 45. The holding chuck 43 is positioned between the holding chucks 16 and 28 described above. The holding chuck 43 holds the storage tank 9 by chucking a portion near the other end 9 b of the storage tank 9. The moving chuck portion 7 described above positions the storage tank 9 by the holding chuck 43 holding the storage tank 9. The movable chuck portion 7 holds the storage tank 9 in cooperation with the above-described holding chuck 28 when the storage tank 9 moves along the axis by holding the storage tank 9 by the holding chuck 43. Thus, the storage tank 9 is prevented from falling off the bearing rotating portion 27, that is, the surface treatment apparatus 1.

As shown in FIG. 8, the electromagnetic coil 8 includes an outer skin 46 formed in a cylindrical shape and a plurality of coil portions 47 arranged in the outer skin 46, and is formed in an annular shape as a whole. The inner diameter of the electromagnetic coil 8 is larger than the outer diameter of the storage tank 9. That is, a space is formed between the inner peripheral surface of the electromagnetic coil 8 and the outer peripheral surface of the storage tank 9. Further, the total length of the electromagnetic coil 8 in the axial direction is sufficiently shorter than the total length of the storage tank 9 in the axial direction. The total length of the electromagnetic coil 8 in the axial direction is preferably 2/3 or less of the total length of the storage tank 9 in the axial direction. In the illustrated example, the inner diameter of the electromagnetic coil 8 is 90 mm, and the length of the electromagnetic coil 8 in the axial direction is 85 mm.

  The outer skin 46 is attached to the above-described electromagnetic coil holding base 18 with its axis, that is, the axis of the electromagnetic coil 8 itself, parallel to the arrow X. The electromagnetic coil 8 is disposed coaxially with the hollow holding member 32, the chuck shaft 39 and the storage tank 9. The plurality of coil portions 47 are arranged in parallel along the circumferential direction of the outer skin 46, that is, the electromagnetic coil 8. The coil unit 47 is applied by a three-phase AC power source 48 shown in FIG. The plurality of coil portions 47 are applied with electric power out of phase with each other, and the plurality of coil portions 47 generate magnetic fields out of phase with each other. And the electromagnetic coil 8 produces | generates the magnetic field (rotating magnetic field) of the rotation direction around the axial center of this electromagnetic coil 8 formed by synthesize | combining these magnetic fields inside.

  The electromagnetic coil 8 described above is applied from a three-phase AC power supply 48 to generate a rotating magnetic field, and is moved by the electromagnetic coil moving unit 5 along the longitudinal direction of its axis, that is, the storage tank 9. And the electromagnetic coil 8 positions the below-mentioned filament material 65 in the outer periphery of the workpiece 2 by the rotating magnetic field mentioned above, and rotates this filament material 65 around the axis of the storage tank 9 and the workpiece 2 ( Move). And the electromagnetic coil 8 makes the filament 65 collide with the outer surface of the workpiece 2 by the rotating magnetic field mentioned above.

  An inverter 49 is provided between the three-phase AC power supply 48 and the electromagnetic coil 8. That is, the surface treatment apparatus 1 includes an inverter 49. The inverter 49 can freely change the frequency, current value, and voltage value of the power applied to the electromagnetic coil 8 by the three-phase AC power supply 48. The inverter 49 changes the frequency, current value, and voltage value of the power applied to the electromagnetic coil 8 to increase or decrease the power applied to the electromagnetic coil 8 by the three-phase AC power supply 48, thereby generating the electromagnetic coil 8. Change the strength of the rotating magnetic field.

  As shown in FIG. 8, the storage tank 9 includes a cylindrical member 50 having a single outer wall (the outer wall is made of a single wall), a plurality of flange members 51, a pair of shaving sealing holders 52, A pair of shavings sealing plates 53, a pair of positioning members 54, a partition member 55 as a plurality of partitioning means, and a pair of sealing plates 56 are provided.

  The cylindrical member 50 is formed in a cylindrical shape and constitutes an outer shell of the storage tank 9. For this reason, the storage tank 9 is formed in a cylindrical shape while the outer wall is formed in a single structure because the cylindrical member 50 is formed in a single structure. The outer diameter of the cylindrical member 50, that is, the storage tank 9, is desirably about 40 mm to 80 mm. Furthermore, the thickness of the cylindrical member 50 is desirably about 0.5 mm to 2.0 mm. The length of the cylindrical member 50 in the axial direction is preferably about 600 mm to 800 mm. The cylindrical member 50 is made of a nonmagnetic material.

  The cylindrical member 50 is provided with a plurality of abrasive grain supply holes 57. Of course, the abrasive grain supply hole 57 passes through the cylindrical member 50 and communicates with the inside and outside of the cylindrical member 50. A sealing cap 58 is attached to the abrasive grain supply hole 57. The abrasive grain supply hole 57 passes the wire material 65 inside, and takes the wire material 65 into and out of the cylindrical member 50, that is, the storage tank 9. The sealing cap 58 closes the abrasive grain supply hole 57 and restricts the filament material 65 from flowing out of the cylindrical member 50, that is, the housing tank 9.

  The plurality of flange members 51 are formed in an annular shape or a cylindrical shape. Most flange members 51 (three in the illustrated example) except for one of the plurality of flange members 51 are attached to one end portion 9a of the cylindrical member 50, and one flange member 51 (hereinafter denoted by reference numeral 51a). ) Is attached to the other end 9 b of the cylindrical member 50.

  One flange member 51 (hereinafter denoted by reference numeral 51 b) among the plurality of flange members 51 attached to the one end 9 a of the cylindrical member 50 is formed in an annular shape and is fitted to the outer periphery of the cylindrical member 50. Yes. Another flange member 51 (hereinafter denoted by reference numeral 51c) is formed in an annular shape and is fitted to the outer periphery of the flange member 51b described above. The remaining flange member 51 (hereinafter denoted by reference numeral 51d) is integrally provided with an annular ring portion 59 and a cylindrical column portion 60. The ring part 59 is standing upright from the outer edge of the cylindrical part 60. As for the flange member 51d, the ring part 59 is fitted to the outer periphery of the flange member 51c.

  A driven shaft 73 is rotatably supported by a bearing 74 on the flange member 51d described above. The driven shaft 73 is formed in a columnar shape and is arranged coaxially with the cylindrical member 50 of the storage tank 9. The hollow holding member 32 is pressed against the end surface of the driven shaft 73. The driven shaft 73 rotates with the hollow holding member 32 and supports one end portion 32 a as a free end of the hollow holding member 32.

  One flange member 51 a described above is formed in an annular shape and is fitted to the outer periphery of the other end portion 9 b of the cylindrical member 50. The flange member 51a passes through the hollow holding member 32 inside. One end 9 a of the cylindrical member 50 forms one end of the storage tank 9, and the other end 9 b of the cylindrical member 50 forms the other end of the storage tank 9.

  Each of the pair of shavings sealing holders 52 is formed in an annular shape. One shaving sealing holder 52 is fitted to the inner circumference of one end 9 a of the cylindrical member 50, and the other shaving sealing holder 52 is fitted to the inner circumference of the other end 9 b of the cylindrical member 50. ing. The other shaving sealing holder 52 passes through the hollow holding member 32 inside.

  The pair of shavings sealing plates 53 are each formed in a mesh shape. One shaving sealing plate 53 is formed in a disc shape and is disposed on the inner periphery of the one end portion 9a of the cylindrical member 50, and is attached to the one shaving sealing holder 52 described above. . Furthermore, one shaving sealing plate 53 passes through the driven shaft 73 on the inner side. The other shaving sealing plate 53 is formed in an annular shape, and is disposed on the inner periphery of the other end 9b of the cylindrical member 50, and is attached to the other shaving sealing holder 52 described above. . The other shavings sealing plate 53 passes through the hollow holding member 32 inside. The shaving sealing plate 53 has a cylindrical member 50, that is, a storage tank 9, in which shavings formed by a wire material 65, which will be described later, collide with the outer surface of the processing object 2 and are scraped off from the processing object 2. Regulates leaking outside.

  The pair of positioning members 54 are formed in a cylindrical shape. One positioning member 54 is fitted to the outer periphery of one end 32 a which is a free end of the hollow holding member 32. The other positioning member 54 is located in the cylindrical member 50 and is fitted to the outer periphery of the central portion 32b of the hollow holding member 32 near the other end portion 9b. The pair of positioning members 54 positions the workpiece 2 on the hollow holding member 32 with the workpiece 2 sandwiched between them. Note that the one end portion 32 a is an end portion of the hollow holding member 32 that is close to the fixed holding portion 4 and away from the moving holding portion 6. The central portion 32 b is on the side inside the storage tank 9 and away from the fixed holding portion 4 of the hollow holding member 32, and forms an end near the moving holding portion 6.

  The partition member 55 includes a main body portion 61 formed in an annular shape and a mesh portion 62. The main body 61, that is, the partition member 55 is fitted to the inner periphery of the cylindrical member 50, is attached to the cylindrical member 50, and passes through the hollow holding member 32 inside. The main body 61, that is, the plurality of partition members 55 are arranged between the pair of shavings sealing plates 53. Further, the main body portion 61, that is, the plurality of partition members 55 are arranged in parallel along the axis P of the cylindrical member 50, that is, along the longitudinal direction with a space between each other. In the illustrated example, seven partition members 55 are provided.

  A through-hole 63 is provided in the main body 61. The mesh part 62 is attached to the main body part 61 so as to close the through hole 63. The mesh part 62 is formed in a mesh shape, allows gas and shavings to pass therethrough, and restricts passage of the wire material 65.

  The plurality of partition members 55 described above partition the space in the cylindrical member 50, that is, the storage tank 9 along the axial center of the cylindrical member 50, that is, the storage tank 9, that is, the axis P of the workpiece 2. In addition, the shaft core P forms both the shaft core of the storage tank 9 and the shaft core of the hollow holding member 32, and the longitudinal direction of the storage tank 9. That is, the axis P and the longitudinal direction of the storage tank 9 are parallel to each other. Furthermore, both the main body portion 61 and the mesh portion 62 described above, that is, the partition member 55 are made of a nonmagnetic material.

  The pair of sealing plates 56 are formed in an annular shape. In addition, the sealing plate 56 is formed in a mesh shape, allows gas and shavings to pass, and restricts passage of the filament material 65. One sealing plate 56 is attached to the partition member 55 closest to the one end 9a, and the other sealing plate 56 is attached to the partition member 55 closest to the other end 9b. The sealing plate 56 passes the caps 64 (described later) attached to both ends of the workpiece 2 inside. The sealing plate 56 restricts the passage of the linear member 65 positioned between the partition members 55, and restricts the flow of the linear member 65 to the outside of the cylindrical member 50, that is, the storage tank 9.

  The storage tank 9 having the configuration described above stores the wire 65 (shown in FIG. 9) made of a magnetic material between the plurality of partition members 55, and holds the workpiece 2 attached to the hollow holding member 32. It is accommodated in the cylindrical member 50. That is, the storage tank 9 stores both the workpiece 2 and the wire material 65. Further, the wire 65 collides with the outer surface of the workpiece 2 by rotating (moving) the outer periphery of the workpiece 2 by the rotating magnetic field described above. The wire 65 collides with the outer surface of the workpiece 2, scrapes a part of the workpiece 2 from the outer surface of the workpiece 2, and roughens the outer surface of the workpiece 2. .

  The wire rod 65 is made of a magnetic material such as austenitic stainless steel or martensitic stainless steel. The wire rod 65 is formed in a short linear column shape. In the illustrated example, the filament material 65 is formed in a columnar shape, and has an outer diameter of 0.5 mm to 1.4 mm and a total length of about 3.0 mm to 14.0 mm.

  As shown in FIG. 8, the recovery unit 10 includes a gas inflow pipe 66, a gas discharge hole 67, a mesh member 68, a gas discharge duct 69, and a dust collector 70 (shown in FIG. 7). . The gas inflow pipe 66 is provided closer to the end of the cylindrical member 50, that is, the storage tank 9 (moving holding portion 6) than the other shaving sealing holder 52, and opens to the inside of the cylindrical member 50, that is, the storage tank 9. The gas inflow pipe 66 is supplied with pressurized gas or the like from a pressurized gas supply source (not shown). The gas inflow pipe 66 guides the pressurized gas into the cylindrical member 50, that is, the storage tank 9.

  The gas discharge hole 67 penetrates through the cylindrical member 50 and communicates the inside and outside of the storage tank 9, and is closer to the end of the cylindrical member 50, that is, the storage tank 9 than one shaving sealing holder 52 (moving and holding unit). (The side away from 6). The mesh member 68 is attached to the cylindrical member 50 so as to close the gas discharge hole 67. The mesh member 68 allows the shavings and gas to pass therethrough and restricts the passage of the filament material 65. The mesh member 68 restricts the filament material 65 from flowing out of the cylindrical member 50, that is, the outside of the housing tank 9.

  The gas exhaust duct 69 is a pipe and is attached in the vicinity of the gas exhaust hole 67. The gas discharge duct 69 surrounds the outer edge of the gas discharge hole 67. The gas discharge hole 67 and the gas discharge duct 69 guide the gas supplied from the gas inflow pipe 66 into the cylindrical member 50, that is, the storage tank 9, to the outside of the cylindrical member 50, that is, the storage tank 9.

  The dust collector 70 is connected to the gas discharge duct 69 and sucks the gas in the gas discharge duct 69. The dust collector 70 sucks the gas in the gas discharge duct 69 to suck the gas in the cylindrical member 50, that is, the storage tank 9 together with the above-described shavings. The dust collector 70 collects shavings. The recovery unit 10 described above supplies gas into the cylindrical member 50, that is, the storage tank 9 through the gas inflow pipe 66, and the gas and dust collector 70 pass the gas through the gas exhaust hole 67 and the gas exhaust duct 69 to remove the shavings into the cylindrical member. 50, that is, the outside of the storage tank 9. Then, the collection unit 10 collects shavings in the dust collector 70.

  As shown in FIG. 7, the cooling unit 11 includes a cooling fan 71 and a cooling duct 72. The cooling fan 71 supplies the pressurized gas to the cooling duct 72. The cooling duct 72 is a pipe. The cooling duct 72 guides the pressurized gas supplied from the cooling fan 71 to the electromagnetic coil 8. The cooling duct 72 blows the pressurized gas supplied from the cooling fan 71 to the electromagnetic coil 8. The cooling unit 11 cools the electromagnetic coil 8 by blowing a pressurized gas onto the electromagnetic coil 8.

  As shown in FIG. 8, the linear encoder 75 includes a main body 77 and a detector 78 that is movably provided on the main body 77. The main body 77 extends linearly and is attached to the base 3. The main body 77 is disposed between the pair of rails 20 in parallel with the rails 20. The overall length of the main body 77 is longer than the storage tank 9 described above. The main body 77 is disposed at a position where both end portions in the longitudinal direction protrude outward from the housing tank 9 described above along the longitudinal direction of the housing tank 9.

  The detector 78 is provided so as to be movable along the longitudinal direction of the main body 77, that is, the storage tank 9. The detector 78 is attached to the electromagnetic coil holding base 18. That is, the detector 78 is attached to the electromagnetic coil 8 via the electromagnetic coil holding base 18.

  The linear encoder 75 described above detects the position of the detector 78 with respect to the main body 77, that is, the storage tank 9, and outputs the detected result toward the control device 76. In this way, the linear encoder 75 detects the relative position of the electromagnetic coil 8 with respect to the storage tank 9, that is, the workpiece 2, and outputs the detection result toward the control device 76.

  The control device 76 is a computer including a known RAM, ROM, CPU, and the like. The control device 76 is connected to the electromagnetic coil moving unit 5, the movement holding unit 6, the moving chuck unit 7, the electromagnetic coil 8, the inverter 49, the recovery unit 10, the cooling unit 11, the linear encoder 75, and the like. These are controlled to control the entire surface treatment apparatus 1.

  The control device 76 stores the strength of the rotating magnetic field of the electromagnetic coil 8 according to the relative position of the electromagnetic coil 8 detected by the linear encoder 75 with respect to the workpiece 2. That is, the control device 76 stores the power applied to the electromagnetic coil 8 by the inverter 49 according to the relative position of the electromagnetic coil 8 with respect to the workpiece 2. In addition, the control device 76 stores the above-described electric power for each part number of the workpiece 2, that is, the hollow body 132.

  In the illustrated example, the control device 76 gradually increases the power applied by the inverter 49 to the electromagnetic coil 8 as the electromagnetic coil 8 moves from the central portion in the longitudinal direction (axial direction) of the workpiece 2 to both ends. A pattern is stored in advance. Then, the control device 76 causes the inverter 49 to change the strength of the rotating magnetic field generated by the electromagnetic coil 8 in accordance with the previously stored power pattern. As described above, in the illustrated example, the control device 76 uses an inverter so that the rotating magnetic field when machining both ends of the workpiece 2 is stronger than the rotating magnetic field when machining the central portion of the workpiece 2. 49, the intensity of the magnetic field generated by the electromagnetic coil 8 is changed. As described above, the control device 76 determines the rotational magnetic field generated by the electromagnetic coil 8 in the inverter 49 based on the relative position of the electromagnetic coil 8 detected by the linear encoder 75 with respect to the storage tank 9, that is, the workpiece 2. Change the strength.

  Further, various input devices such as a keyboard and various display devices such as a display are connected to the control device 76.

  Next, a process of manufacturing the hollow body 132 by processing (roughening) the outer surface of the workpiece 2 using the surface treatment apparatus 1 having the above-described configuration will be described below.

  First, the workpiece number 2, that is, the product number of the hollow body 132 is input from the input device to the control device 76. And the cylindrical cap 64 is fitted to the outer periphery of the both ends of the longitudinal direction (axial direction) of the workpiece 2. Then, the other positioning member 54 described above is fitted to the outer periphery of the hollow holding member 32. Then, the hollow holding member 32 is passed through the workpiece 2 having caps 64 attached to both ends. Thereafter, the one positioning member 54 described above is fitted to the outer periphery of the hollow holding member 32. Then, the chuck shaft 39 of the chuck cylinder 34 is reduced, and the workpiece 2 is fixed to the hollow holding member 32. At this time, the hollow holding member 32 and the workpiece 2 are coaxial. In this way, the workpiece 2 is attached to the hollow holding member 32.

  Then, the workpiece 2 and the hollow holding member 32 are housed in the housing tank 9, and the filament material 65 is supplied into the cylindrical member 50 of the housing tank 9. In this way, the wire rod 65 and the workpiece 2 are stored in the storage tank 9. Further, the storage tank 9 is chucked by the holding chucks 28 and 43. In this way, the workpiece 2 and the storage tank 9 are attached to the movable holding unit 6. Then, the cylindrical member 50, the hollow holding member 32, the workpiece 2 and the like of the storage tank 9 become coaxial.

  Of course, the above-described operation is performed while adjusting the position of the moving base 26 with the actuators 24 and 25. Furthermore, the above-described operation is, of course, performed while adjusting the position of the holding base 41. The holding chuck 16 causes the one end 9a of the storage tank 9 to be chucked, for example, so that the fixed holding section 4 holds the one end 9a of the storage tank 9.

  And while supplying gas in the storage tank 9 through the gas inflow pipe 66 of the collection | recovery part 10, while attracting | sucking the gas in the storage tank 9 with the dust collector 70, the gas pressurized by the cooling part 11 is made into the electromagnetic coil 8. Let spray.

  Then, the workpiece 2 is rotated around the axis P together with the hollow holding member 32 by the driving motor 33. Thereafter, electric power from the three-phase AC power supply 48 is applied to the electromagnetic coil 8 to generate a rotating magnetic field in the electromagnetic coil 8. Then, the wire rod 65 located inside the electromagnetic coil 8 revolves (rotates or moves) around the axis P while rotating, and the wire rod 65 collides with the outer surface of the workpiece 2, The outer surface of the workpiece 2 is roughened.

  And the electromagnetic coil moving part 5 moves the electromagnetic coil 8 along the axial core P suitably. Then, the wire rod 65 that has entered the inside of the electromagnetic coil 8 moves (spins and revolves) by the rotating magnetic field described above, and the wire rod 65 that has come out of the inside of the electromagnetic coil 8 stops. Moreover, since the partition member 55 partitions the space in the storage tank 9, the wire member 65 is restricted from moving beyond the partition member 55, and the wire member 65 that has come out from the inside of the electromagnetic coil 8 is described above. Will escape from the rotating magnetic field. Further, when the electromagnetic coil moving unit 5 reciprocates the electromagnetic coil 8 a predetermined number of times along the arrow X, the roughening of the outer surface of the workpiece 2 is completed.

  When the roughening process of the outer surface of the workpiece 2 described above is completed, the application of electric power to the electromagnetic coil 8 is stopped and the drive motor 33 is stopped. Further, the recovery unit 10 and the cooling unit 11 are stopped. Then, the holding tank 16 of the holding chuck 16 of the fixed holding unit 4 is released from holding, and the holding chuck 43 of the moving chuck unit 7 and the holding chuck 28 of the moving holding unit 6 hold the holding tank 9 while holding the holding tank 9. The moving base 26 is separated from the fixed holding portion 4 along the arrow X by the actuator 24. Then, the storage tank 9 is separated from the fixed holding part 4. Then, the processing target object 2 whose outer surface has been roughened is taken out from the storage tank 9, and the new processing target object 2 is stored in the storage tank 9. In this way, the hollow portion 132 is obtained by roughening the portion 141 c surrounded by the iris-shaped groove on the outer surface of the workpiece 2.

  According to the present embodiment, the plurality of grooves 141a in which the hollow body 132 extends in the direction inclined with respect to the rotational thrust direction and the plurality of grooves 141b in the direction inclined in the opposite direction with respect to the thrust direction intersect. The groove 141 is formed into a groove-like groove, and the portion 141c surrounded by the grooves 141a and 141b on the outer surface is roughened by colliding with the wire 65 to form a recess. In addition to suppressing the occurrence of shading unevenness and sleeve pitch shading unevenness, the occurrence of pitch-like horizontal black stripes and pitch-like vertical black stripes can also be suppressed over time.

  If the dent due to the roughening treatment is not formed, the developer is transported more in the grooves 141a and 141b than in the portion 141c surrounded by the grooves 141a and 141b on the outer surface. Accumulated. For this reason, an abnormal image having periodicity (shading unevenness) is likely to occur. That is, in order to suppress abnormal images (light density unevenness), it is effective to reduce the difference in the developer conveyance amount between the portion 141c surrounded by the grooves 141a and 141b and the portions of the grooves 141a and 141b. Therefore, the developer conveying ability of the portion 141c surrounded by the grooves 141a and 141b is improved by roughening the portion 141c surrounded by the grooves 141a and 141b to form a dent, and the portions 141a and 141b are surrounded by the grooves 141a and 141b. The difference in developer conveyance between the portion 141c and the portions of the grooves 141a and 141b is reduced, and abnormal images (light / dark unevenness) can be suppressed. In the case of an iris-shaped groove, since the groove 141a and the groove 141b intersect each other, a large amount of developer is transported particularly at the groove intersection. As a result, a development density difference occurs between the intersection of the grooves 141a and 141b and the other portion, and an abnormal image (pitch-like horizontal black stripe, pitch-like vertical black stripe) is generated. By roughening the portion 141c surrounded by the groove of the hollow body in which the iris-shaped groove is arranged to form a dent, the difference in developer conveyance between the intersection portion of the groove and the other portion is reduced, Abnormal images (pitch-like horizontal black stripes, pitch-like vertical black stripes) can be suppressed.

  A linear material 65 that is much larger than abrasive grains used for sandblasting or the like is collided with the outer surface of the workpiece 2 and the outer surface of the workpiece 2 (hollow body 132) is roughened. . In other words, as compared with the unevenness 139a formed by sandblasting conventionally used as shown in FIG. 11, the present embodiment makes the unevenness 139 by colliding the above-mentioned filament 65 as shown in FIG. Is formed smoothly.

  In the unevenness 139a of the conventional hollow body 132a formed by sandblasting shown in FIG. 11, since the interval between the unevenness 139a is narrow, the magnetic carrier 135 is on the fine unevenness 139a. For this reason, the magnetic carrier 135 is easy to slide on the unevenness 139a, and each ear has a magnetic moment due to the magnetic field from the magnetic field generating means, and the ears having the magnetic moment in the same direction are adjacent to each other. It becomes a state. For this reason, the ears repel each other and try to leave each other. As a result, in the unevenness 139a formed by sandblasting shown in FIG. 11, the magnetic carrier 135, that is, the developer 126a is thin and long (thin on the outer peripheral surface of the hollow body 132a, and the protruding amount from the hollow body 132a is long. ) Stand up.

  For this reason, in the hollow body 132a shown in FIG. 11, when the amount of the developer 126a pumped from the state shown by the solid line to the state shown by the two-dot chain line decreases, the heading shape is similar between the solid line and the two-dot chain line. Therefore, the width, ie, the area of the developer 126a that is raised from the outer peripheral side of the hollow body 132a described above is remarkably reduced.

  On the other hand, as shown in FIG. 10, the interval between the irregularities 139 formed by colliding the above-described wire rod 65 of the present embodiment is much larger than the interval between the irregularities 139a shown in FIG. Therefore, the unevenness 139 of this embodiment is much smoother than the unevenness 139a shown in FIG. For this reason, in this embodiment, as shown in FIG. 10, a spike shape is formed with each dent as a root. That is, a head is formed on each dent.

  For this reason, in this embodiment, the magnetic carrier 135, that is, the developer 126 is thicker and shorter than the case shown in FIG. 11 (thick on the outer peripheral surface of the hollow body 132 and has a shorter protruding amount from the hollow body 132). Stand up. For this reason, in the hollow body 132 of the present embodiment shown in FIG. 10, the amount of the developer 126 pumped up from the state indicated by the solid line to the state indicated by the two-dot chain line is reduced, and the heading shape is changed from the solid line to the two points. Even if the shape is similar to that of the chain line, the width, ie, the area of the developer 126 sprouting from the outer peripheral side of the hollow body 132 described above is hardly reduced.

  For this reason, the developing device 113 of this embodiment is adsorbed on the outer surface of the hollow body 132 even when the unevenness 139 on the outer surface of the hollow body 132 is worn due to secular change and the pumping amount of the developer 126 is reduced. The amount of decrease in the area of the developer 126 viewed from the outer peripheral side can be suppressed. Therefore, it is possible to obtain a high-quality image over a long period of time by suppressing the occurrence of image unevenness due to secular change.

  Moreover, since the filament 65 is made to collide with an outer surface at random, it can prevent that the axial center of the hollow body 132 curves, an inner-outer diameter changes, or a cross-sectional shape becomes elliptical. That is, the deflection accuracy of the hollow body 132 can be kept high. Therefore, unevenness in the amount of the developer 126 supplied to the photosensitive drum 108 can be prevented, and unevenness in density (sleeve pitch unevenness) can be prevented from occurring in the formed image.

  Since the wire rod is positioned in the rotating magnetic field and the wire rod 65 collides with the outer surface of the workpiece 2 (hollow body 132), the wire rod 65 is more randomly placed on the outer surface of the workpiece 2. It can be made to collide. Therefore, a more uniform unevenness 139 can be formed on the outer surface of the hollow body 132, and a more uniform image can be obtained.

  Moreover, since the unevenness | corrugation 139 can be formed in the outer surface of the hollow body 132 by positioning the filament 65 in a rotating magnetic field, it prevents that the process concerning the formation of the unevenness 139 on the outer surface of the hollow body 132 increases. it can. Therefore, it is possible to prevent the process for forming the unevenness 139 on the outer surface of the hollow body 132 from becoming complicated, and it is possible to prevent the cost for processing from rising.

  Since the processing object 2 is accommodated in the storage tank 9 together with the wire material 65, the wire material 65 can be reliably collided with the outer surface of the processing object 2 (hollow body 132). Therefore, the outer surface of the hollow body 132 is reliably subjected to the roughening treatment.

  In addition, since the developing device 113 includes the developer carrier 115 described above, it is possible to reliably prevent unevenness in the image.

  Since the developer 126 having an average particle size of the magnetic carrier 135 of 20 μm or more and 50 μm or less is used, an excellent image with excellent granularity and little unevenness can be obtained. When the average particle size of the magnetic carrier 135 is less than 20 μm, the magnitude of the magnetization of each of the magnetic carriers 135 becomes small, so that the magnetic binding force of the magnetic carrier 135 from the developer carrier 115 becomes weak, Since the magnetic carrier 135 is easily attracted to the photosensitive drum 108, it is not desirable. If the average particle diameter of the magnetic carrier 135 exceeds 50 μm, the electric field between the magnetic carrier 135 and the electrostatic latent image on the photosensitive drum 108 becomes sparse, and a uniform image cannot be obtained (the image quality deteriorates). Therefore, it is not desirable.

  Since the process cartridges 106Y, 106M, 106C, and 106K and the image forming apparatus 101 include the developing device 113 described above, it is possible to reliably prevent unevenness in an image.

  By moving the electromagnetic coil 8, the hollow body 132 is processed, and at the same time, the wire 65 is suddenly pulled out of the rotating magnetic field. For this reason, the strength of the magnetic field acting on the wire rod 65 is abruptly changed (decreased), and the magnetic domains aligned in the wire rod 65 become uneven so that the magnetization is weakened, and the hollow body 132 is processed. At the same time, the effect of removing the residual magnetization of the wire rod 65 is achieved.

  As a result, a degaussing device or the like that removes the residual magnetization of the wire rod 65 that is separate from the surface treatment device 1 becomes unnecessary. Therefore, it becomes possible to easily demagnetize the wire material 65, and the hollow body 132 can be continuously processed for a long time, so that the processing efficiency of the surface treatment can be improved. Therefore, the surface treatment apparatus 1 as a mass production apparatus on the premise of mass production of the hollow body 132 can be obtained.

  Since the hollow body 132 is held at the center of the housing tank 9, the linear member 65 can collide with the outer surface of the hollow body 132 substantially uniformly. Therefore, the outer surface of the hollow body 132 can be processed uniformly.

  By moving (revolving) the wire rod 65 on the outer periphery of the hollow body 132, the wire rod 65 can be made to collide with the outer surface of the workpiece 2 reliably, and the processing of the hollow body 132 can be ensured. It can be carried out.

  Since the hollow body 132 is rotated, the linear member 65 can collide uniformly with the outer surface of the hollow body 132, and the outer surface of the hollow body 132 can be processed more uniformly.

  Since the electromagnetic coil 8 is shorter than the storage tank 9, it is possible to increase the rotating magnetic field and cause the electromagnetic coil 8 to be generated in the storage tank 9 as compared with the case where the electromagnetic coil 8 uses a surface treatment apparatus having a length substantially equal to that of the storage tank 9. Loss of rotating magnetic field can be reduced. Accordingly, it is possible to improve the processing efficiency of the hollow body 132 and further reduce power consumption.

  Moreover, since the electromagnetic coil 8 is shorter than the storage tank 9, both ends of the storage tank 9 can be supported. Thereby, it is possible to prevent the storage tank 9 from vibrating (moving) due to the movement of the wire rod 65 and the like, and the wire rod 65 can collide with the outer surface of the hollow body 132 more uniformly. The outer surface of can be processed even more uniformly.

  Since the storage tank 9 is cylindrical, the storage tank 9 does not hinder the circumferential behavior of the wire material 65 when a rotating magnetic field is applied to the wire material 65. Therefore, stable processing is possible.

  The partition member 55 partitions the space in the storage tank 9 in the longitudinal direction. For this reason, the partition member 55 limits the movable region (spinning / revolution region) of the wire rod 65 and enables more efficient processing.

  Moreover, since it can restrict | limit that the wire rod 65 moves beyond the partition member 55, the wire rod 65 and a rotating magnetic field can be moved relatively reliably, and this wire rod 65 can be reliably demagnetized. it can.

  Since it is made of a non-magnetic material, the partition member 55 is not magnetized, and the partition member 55 interferes with the behavior of the wire rod 65, or shavings are magnetized and stick to the partition member 55. Absent. For this reason, it becomes possible to process stably.

  Since a plurality of partition members 55 are provided, it is possible to divide the range in which the outer surface of the hollow body 132 is roughened. For this reason, the partition member 55 reliably limits the movable region (spinning / revolution region) of the wire rod 65, and enables more efficient processing.

  Moreover, since it can control that the wire 65 moves over the partition member 55, the demagnetization of the wire 65 can be performed reliably.

  Since the outer wall of the cylindrical member 50 of the storage tank 9 has a single structure, the distance from the electromagnetic coil 8 to the hollow body 132 can be shortened, and the rotating magnetic field generated by the electromagnetic coil 8 can be used more efficiently for processing. It becomes possible to do.

  The sealing plate 56 makes it possible to prevent the filament 65 from flowing out of the storage tank 9, improving workability and productivity during processing, and the effect is further enhanced by continuous processing. The processing apparatus 1 can produce (process) the hollow body 132 as a mass production apparatus on the premise of mass production.

  Next, the inventors of the present invention formed a total of 120 grooves having a groove inclination angle of 25 °, a groove angle of 65 °, and a groove depth of 90 μm in a material A6063 and a hollow body having a diameter of 25 mm, each having 60 inclination directions. The developer carrier subjected to iris processing is processed under the conditions of the following comparative example, Example 1 and Example 2, and then the initial image and the image after feeding 300,000 sheets are compared. It was.

  Here, the groove angle is a in FIG. 12 showing a cross section of the groove of the hollow body 132, that is, the angle of the bottom of the V-shaped grooves 141a and 141b in the iris processing. The groove depth is b in FIG. 12, that is, the length from the bottom of the grooves 141a and 141b to the surface of the hollow body.

(Comparative example)
As a comparative example, the surface of the developer carrying member was used without being roughened. The surface roughness Rz of the part surrounded by the groove on the outer surface at this time was 5 μm (polished surface).

  When a solid image was formed by an image forming apparatus using the developer carrying member obtained under the above conditions, pitch-like vertical black streaks occurred in the initial image. Even after feeding 300,000 sheets, pitch-like vertical black streaks equivalent to those in the initial stage were generated.

Example 1
As Example 1, the surface of the developer carrying member was used after being subjected to sandblast treatment. Alumina-based abrasive # 100 was used for the sandblast treatment. At this time, the surface roughness Rz of the portion surrounded by the groove on the outer surface was 12 μm.

  When a solid image was formed with an image forming apparatus using the developer carrying member obtained under the above conditions, a good image with no shading unevenness was obtained in the initial image. After feeding 300,000 sheets, pitch-like vertical black streaks occurred although the level was within an allowable level.

(Example 2)
As Example 2, the surface of the developer carrying member was subjected to a roughening treatment using the surface treatment apparatus shown in FIGS. 8 and 9. For the roughening treatment, KPR110AD and Φ0.8 × 10 were used as the line material. At this time, the surface roughness Rz of the portion surrounded by the groove on the outer surface was 14 μm.

  When a solid image was formed with an image forming apparatus using the developer carrying member obtained under the above conditions, a good image with no shading unevenness was obtained in the initial image. Even after feeding 300,000 sheets, a good image with no shading unevenness was obtained.

  From the above results, it has been clarified that abnormal images (shading unevenness, pitch-like vertical black lines) can be suppressed by roughening the portion surrounded by the iris-shaped grooves on the outer surface of the developer carrying member. Also, it has been clarified that abnormal images (shading unevenness, pitch-like vertical black streaks) can be suppressed even when used over time. Furthermore, by roughening the surface so that a large number of oval-shaped dents are randomly provided by the surface roughening treatment with the line material, abnormal images (shading unevenness, pitch-like vertical black stripes) can be further suppressed. It became clear. In addition, it has been clarified that abnormal images (shading unevenness, pitch-like vertical black streaks) can be further suppressed even when used over time.

  The present invention is not limited to the above embodiment. That is, various modifications can be made without departing from the scope of the present invention.

1 is an explanatory diagram viewed from the front of a configuration of an image forming apparatus according to an embodiment of the present invention; FIG. 2 is a sectional view of a process cartridge of the image forming apparatus shown in FIG. 1. It is sectional drawing which follows the III-III line | wire in FIG. FIG. 4 is a perspective view of a hollow body as a developer carrier of the developing device shown in FIG. 3. It is sectional drawing of the magnetic carrier of the developing agent of the image development apparatus shown by FIG. It is explanatory drawing which expands and shows the outer surface of the hollow body shown by FIG. It is a perspective view which shows the outline of a structure of the surface treatment apparatus which performs a roughening process on the outer surface of the hollow body shown by FIG. It is sectional drawing which follows the II-II line in FIG. It is a perspective view of the magnetic abrasive grain used with the surface treatment apparatus shown by FIG. It is sectional drawing which shows typically the state which rose on the outer surface of the hollow body shown by FIG. It is sectional drawing which shows typically the state which rose on the outer surface of the hollow body to which the conventional sandblast was given. It is sectional drawing of the groove | channel provided in the hollow body shown by FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Surface treatment apparatus 2 Processing target object 65 Line material 101 Image forming apparatus 106Y, 106M, 106C, 106K Process cartridge 113 Developing apparatus 115 Developer support body 131 Development area 132 Hollow body 133 Magnetic field generating means 135 Magnetic carrier 136 Core material 139 Unevenness (dent)
141a, 141b groove 141c part surrounded by groove

Claims (8)

An iris-shaped groove formed on the outer surface such that a plurality of grooves extending in a direction inclined with respect to the rotational thrust direction and a plurality of grooves extending in a direction inclined opposite to the rotational thrust direction intersect. A developer carrying body comprising: a hollow body having a portion surrounded by the iris-shaped groove; and a magnetic field generating means for adsorbing the developer on the outer surface by magnetic force inside the hollow body,
A developer carrying member, wherein a portion surrounded by the iris-shaped groove on the outer surface of the hollow body is randomly provided with a recess formed by a roughening treatment.   2. The developer carrying member according to claim 1, wherein a number of elliptical recesses are randomly provided in a portion surrounded by the iris-shaped groove on the outer surface of the hollow body.   3. A plurality of elliptical depressions in a portion surrounded by the iris-shaped groove on the outer surface of the hollow body are formed by short line-shaped wire rods that are randomly collided. The developer carrying member as described.   A developing device comprising the developer carrying member according to claim 1.   The developing device according to claim 4, wherein the developer contains toner and a magnetic carrier, and the average particle diameter of the magnetic carrier is in a range of 20 μm or more and 50 μm or less.   A process cartridge comprising the developing device according to claim 4.   An image forming apparatus comprising the process cartridge according to claim 6.   A color image forming apparatus comprising a plurality of process cartridges according to claim 6.

Images