JP4871586B2 - Developer carrying member, developing device, process cartridge, and image forming apparatus - Google Patents

Description

  The present invention relates to a developer carrying member, a phenomenon device, a process cartridge, and an image forming apparatus used for a copying machine, a facsimile machine, a printer, and the like. More specifically, the developer carried on a developing sleeve is replaced with an electrostatic latent image carrying member. The present invention relates to a developer carrying member and a developing device which are conveyed to a developing area facing each other with a gap and develop a latent image on the latent electrostatic image bearing 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.

  Various image forming apparatuses such as copiers, facsimile machines, printers, etc., form various images using a so-called two-component developer containing toner and magnetic carrier (hereinafter simply referred to as developer) (for example, Patent Document 1) is used. In this type of developing device, the developer is conveyed to a developing region facing a photosensitive drum as an electrostatic latent image carrier, and the electrostatic latent image formed on the photosensitive drum is developed with the developer to form a toner. A developing roller as a developer carrying member for forming an image is provided.

  The developing roller forms a magnetic field so that a developing sleeve made of a non-magnetic material formed in a cylindrical shape and a rising edge of the developer are accommodated in the developing sleeve and the surface of the developing sleeve is generated. A magnet roller is provided. On the developing roller, when the developer spikes, the magnetic carrier spikes on the developing sleeve so as to follow the lines of magnetic force generated by the magnet roller, and toner adheres to the spiked magnetic carrier.

  The developing device disclosed in Patent Document 1 described above is attached to the photosensitive drum and the developing sleeve of the developing roller by setting the attenuation rate of the magnetic pole facing the photosensitive drum of the magnet roller of the developing roller to 40% or more. Friction generated between the magnetic carrier and the magnetic carrier is reduced to prevent the magnetic carrier from being charged by the friction. The developing device disclosed in Patent Document 1 prevents a so-called trailing edge white spot (a phenomenon in which the trailing edge portion of the image is not sufficiently formed) from occurring in the formed image.

Patent Document 1 discloses that a so-called rare earth magnet containing a rare earth element is used as the magnetic pole described above in order to prevent the above-described trailing edge blanking (see, for example, Patent Document 2).
JP 2000-347506 A JP 2004-266151 A

  Developers composed of the above-described toner and magnetic carrier generally have an additive embedded in the surface of the magnetic carrier or wear the surface layer of the magnetic carrier when used for a long time, and the developer itself. The powder characteristics of these are easy to change. When the developer described above is used for a long period of time, the powder characteristics change as described above, and the amount pumped up to the developing sleeve is likely to change (in many cases, the developer is pumped up as the usage period becomes longer). The amount that is produced decreases.)

  Various surface-roughening processes are performed on the outer surface of the developing sleeve of the developing roller described above in order to draw up the developer and transport the developer to the photosensitive drum.

  For example, a development sleeve that has been sandblasted has very fine irregularities formed on its outer surface, so that the irregularities are gradually scraped by a developer or the like, and as the number of printed sheets increases, Due to the change, the above-described unevenness is cut and flattened. Therefore, in the developing sleeve subjected to the sandblasting process described above, the amount of developer transport is gradually decreased with the change in the powder characteristics of the developer described above, and the formed image is gradually thinned. Produce. In particular, when the magnetic pole containing the rare earth element described above is used, the deterioration of the image quality due to the decrease in the pumping amount of the developer becomes remarkable.

  Further, the developing sleeve in which the V groove is formed on the outer surface is much larger than the unevenness formed by the sandblasting process described above. In other words, since the V-groove is much larger (deeper) than the magnetic carrier of the developer, the developer sleeve in which the V-groove is formed is difficult to wear, and the developer transport amount decreases with aging. There is nothing. However, in the developing sleeve having the V groove formed on the outer surface, the developer conveyed in the V groove is larger than the developer conveyed in the portion where the V groove is not provided. Unevenness is likely to occur in the transport amount of the developer. Therefore, the developing sleeve having the V-groove formed on the outer surface tends to cause density unevenness in the formed image. Further, the developing sleeve having a V-groove formed on the outer surface has a so-called runout accuracy such that the shaft core is bent or distorted or the inner / outer diameter changes in the axial direction when the V-groove is formed by machining. There was a tendency to decrease. Therefore, the developing sleeve in which the V-groove is formed on the outer surface described above is likely to cause unevenness in the image due to the above-described decrease in shake accuracy.

  The present invention has been made in view of the above background, and can suppress a decrease in the transport amount of the developer due to secular change and can prevent the occurrence of image unevenness, a developing device, and the development device It is an object of the present invention to provide a process cartridge provided with a developing device and an image forming apparatus.

The developer carrying member according to claim 1 includes a magnet roller and the magnet roller, and adsorbs the developer to the outer surface by the magnetic force of the magnet roller, and the developer toner is applied to the electrostatic latent image carrier. a developing sleeve receiving passing the developing region is formed on the outer surface, the developer carrying member having a is a (i) attenuation factor of the normal direction of the magnetic flux density of the developing area is 40% or more, (b) A number of elliptical dents are randomly provided on the outer surface of the developing sleeve, and (c) the plurality of elliptical dents are positioned in the rotating magnetic field and rotated by the rotating magnetic field. (D) the plurality of elliptical dents, the longitudinal direction of which is a dent along the axial direction of the developing sleeve, and the longitudinal direction thereof is the above-mentioned And a recess whose longitudinal direction is along the axial direction of the developing sleeve is greater than a recess whose longitudinal direction is along the circumferential direction of the developing sleeve . .
The developer carrier according to claim 2 is characterized in that, in the developer carrier according to claim 1, outer edges of both ends of the linear member are chamfered in a circular arc shape over the entire circumference. Yes.
The developer carrier according to claim 3 is the developer carrier according to claim 1 or 2, wherein a major axis of the dent is 0.05 mm or more and 0.3 mm or less. The short diameter is 0.02 mm or more and 0.1 mm or less.

The developer carrying member according to claim 4 is the developer carrying member according to any one of claims 1 to 3 , wherein the magnet roller has another member at a portion corresponding to the developing region. A cylindrical magnet molded body provided with at least one concave groove that can be embedded, and a long magnet embedded in the groove and having a higher magnetic force than the cylindrical magnet molded body and containing a rare earth element And a molded body.

The developer carrier according to claim 5 is the developer carrier according to claim 4 , wherein the concave groove of the cylindrical magnet molded body is a downstream side of the developing sleeve in the rotation direction and adjacent to the groove. The second groove is further provided with a concave second groove so that another member can be embedded therein, and the second groove is embedded in the second groove and has a higher magnetic force than the cylindrical magnet molded body and contains a rare earth element. A magnet molded body is further provided.

The developer carrying member according to claim 6 is the developer carrying member according to claim 4 or 5 , wherein the long magnet molded body comprises magnetic powder containing rare earth elements and thermoplastic resin fine particles. It is characterized in that it is a long magnet formed by compression-molding the compression molding magnet compound it has in a magnetic field.

Developer carrying member according to claim 7 is the developer carrying member according to claim 6, wherein the magnetic powder, the bulk density thereof is adjusted to 3.3g / cm ³ ~4.0g / cm ³ It is characterized by being.

The developer carrier according to claim 8 is the developer carrier according to claim 6 or 7 , wherein the average particle diameter of the thermoplastic resin fine particles is equal to the average particle diameter of the magnetic particles of the magnetic powder. It is characterized by being 1/10 or less.

A developer carrier according to claim 9 is the developer carrier according to any one of claims 6 to 8 , wherein the thermoplastic resin fine particles are obtained by an emulsion polymerization method or a suspension polymerization method. It is a manufactured spherical fine particle.

The developer carrier according to claim 10 is the developer carrier according to any one of claims 1 to 9 , wherein the developing sleeve is accommodated in an accommodating tank together with the filament material. The magnetic field generator generates the rotating magnetic field in the storage tank.

The developer carrying member according to claim 11 is the developer carrying member according to claim 10 , wherein the developing member accommodated in the accommodating tank is rotated about its axis while the linear member is It is characterized by a collision.

The developing device according to claim 12, in the developing apparatus having a developer carrying member having a developing sleeve for attracting the developer to the outer surface, as the developer carrying member, of the claims 1 to 11 The developer carrying member according to any one of the above items is provided.

According to a thirteenth aspect of the present invention , in the process cartridge having at least a developing device, the developing device includes the developing device according to the twelfth aspect.

According to a fourteenth aspect of the present invention , in the image forming apparatus including at least a process cartridge having at least a developing device, the process cartridge according to the thirteenth aspect is provided as the process cartridge.

  According to the developer carrying member of the first aspect, since the outer surface has an elliptical recess larger than the recess formed by the conventional sandblasting process, the recess is less likely to be worn even with aging. Therefore, it is possible to suppress a decrease in the transport amount of the developer due to secular change.

  Further, since the developing sleeve has the elliptical recesses formed on the outer surface at random, the developer accumulates in the recesses, so that the locations where the developer accumulates are randomly disposed on the outer surface. Therefore, it is possible to prevent image unevenness.

Further, since the longitudinal direction has more dents along the axial direction than the dents along the circumferential direction, the developer to be pumped is arranged side by side along the axial direction. The developer thus pumped is less likely to fall off from the outer surface of the developing sleeve, and thus the elliptical recess has the same effect as the V-groove that has been conventionally used to secure the developer pumping amount. be able to.
Further, since the linear rod material is randomly collided with the outer surface to form an elliptical recess, it is possible to prevent the shaft core of the developing sleeve from being bent, the inner and outer diameters to be changed, and the cross-sectional shape from becoming elliptical. In other words, the runout accuracy of the developing sleeve can be kept high.
Furthermore, since random irregularities are formed on the developing sleeve as the object to be processed, it is possible to prevent unevenness in the amount of developer supplied to the electrostatic latent image carrier, and unevenness in density is formed in the formed image. It can be prevented from occurring.
In addition, since the linear material positioned in the rotating magnetic field collides with the outer surface of the developing sleeve, the linear material collides with the outer surface of the developing sleeve more randomly, and thus more uniform unevenness is developed. It can be formed on the outer surface of the sleeve, and a more uniform image can be obtained.
Further, by positioning the filament material in the rotating magnetic field, irregularities can be formed on the outer surface of the developing sleeve, so that it is possible to prevent an increase in the number of steps when forming irregularities on the outer surface of the developing sleeve. It is possible to prevent the process for forming irregularities on the outer surface of the sleeve from becoming complicated, and to prevent the cost for processing from rising.
Further, by positioning the filament material in the rotating magnetic field, irregularities can be formed on the outer surface of the developing sleeve, so that the longitudinal direction of the filament material is in the radial direction of the rotating magnetic field and the center in the longitudinal direction. The outer periphery of the developing sleeve revolves while rotating around the center, and for this reason, the outer edges of both ends in the longitudinal direction of the filament material collide with the developing sleeve, and the unevenness formed on the outer surface of the developing sleeve In particular, the number of dents along the axial (longitudinal) direction of the developing sleeve increases, and the dent formed on the outer surface of the developing sleeve surely exhibits the same effect as the V-groove that has been used conventionally. The amount of developer pumped up can be secured.
Further, since the linear material is randomly collided with the outer surface of the developing sleeve by the rotating magnetic field, the unevenness formed on the outer surface of the developing sleeve is more reliably randomized, and thus the image formed by the developing sleeve Unevenness can be prevented from occurring.
The attenuation factor of the magnetic flux density in the normal direction is 1 mm along the normal direction (radial direction) of the developing sleeve from the outer surface with respect to the magnetic flux density in the developing region on the outer surface of the developing sleeve. The attenuation rate of the magnetic flux density at a distant position is shown.
According to the invention described in claim 2, since the outer edge portions at both ends in the longitudinal direction of the wire rod are chamfered in a circular arc shape in cross section, the outer surface of the developing sleeve as the processing object is smooth on the outer surface. Can prevent unevenness of the developing sleeve, such as the developer of the developing sleeve, that is, the magnetic carrier, over time.
According to the third aspect of the present invention, the major axis of the elliptical depression is 0.05 mm or more and 0.3 mm or less, and the minor axis of the elliptical depression is 0.02 mm or more and 0.8 mm or less. Since it is 1 mm or less, an oval-shaped dent much larger than the dent formed by the conventional sandblasting process is formed on the outer surface of the developer carrying member. Become. Therefore, it is possible to suppress a decrease in the transport amount of the developer due to aging.

According to the developer carrying member of the fourth aspect , since the long magnet molded body having a high magnetic force containing a rare earth element is embedded in a portion corresponding to the developing region, the developing ability is good and the formed image is It is possible to prevent the occurrence of white spots.

According to the developer carrying member of claim 5 , since the long magnetic molded body containing the rare earth element and embedded in the adjacent portion downstream of the portion corresponding to the developing region is embedded, the developer magnetic carrier Can continue to adhere to the outer surface of the developing sleeve, and the magnetic carrier can be prevented from adhering to the electrostatic latent image carrier.

According to the developer carrier of the sixth aspect of the invention , since the long magnet molded body formed by compression molding the compression molding magnet compound in a magnetic field is provided, the concentration of the binding resin is reduced and the magnetic properties are reduced. It can be set as a large elongate magnet molding, For that reason, a high magnetism long magnet molding of 13 MGOe or more (100 mT or more) can be obtained. Therefore, it is possible to obtain a developer carrying member having a good developing ability.

According to the developer carrying member according to claim 7, since the bulk density of the magnetic powder is adjusted to ^{3.3g / cm 3 ~4.0g / cm 3} , at the time of molding, the magnetic particles of the magnetic powder Since the density of the magnetic powder of the long magnet molded body can be increased by being densely packed, a long magnet molded body with a high magnetic force is obtained.

According to the developer carrier of claim 8 , since the average particle diameter of the thermoplastic resin fine particles is 1/10 or less of the magnetic particles of the magnetic powder, the gap between the magnetic particles of the magnetic powder is formed in the thermoplastic resin fine particles. As a result, it becomes possible to increase the molding density of the long magnet compact, and to improve the magnetic properties of the long magnet compact.

According to the developer carrying member of claim 9 , since the thermoplastic resin fine particles are spherical fine particles produced by an emulsion polymerization method or a suspension polymerization method, it is possible to increase the density of the compression molded product, Therefore, the magnetic characteristics can be further improved. Further, when the spherical particles are used, the area covered with the magnetic powder is improved, so that the exposed area of the magnetic powder on the surface of the long magnet molded body can be reduced, and therefore, a rust prevention effect is produced.

In the developer carrying member according to the tenth aspect , since the developing sleeve is accommodated in the accommodating tank together with the filament material, the filament material reliably collides with the outer surface of the developing sleeve. The surface can be reliably roughened.

In the developer carrying member according to claim 11 , since the linear member collides with the outer surface of the developing sleeve rotating in the storage tank, the linear member collides with the outer surface of the developing sleeve even more randomly. Therefore, the dents can be formed more uniformly while maintaining higher accuracy, and an image with less unevenness can be obtained.

Since the developing device according to the twelfth aspect includes the developer carrier described above, it is possible to suppress a decrease in the transport amount of the developer due to secular change and to prevent occurrence of image unevenness.

Since the process cartridge according to the thirteenth aspect includes the developing device according to the twelfth aspect, it is possible to suppress a decrease in the developer conveyance amount due to secular change and to prevent image unevenness.

Since the image forming apparatus according to the fourteenth aspect includes the process cartridge according to the thirteenth aspect, it is possible to suppress a decrease in the developer conveyance amount due to secular change and to prevent image unevenness.

  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 the developing device according to the embodiment of the image forming apparatus shown in FIG. 3 is a cross-sectional view taken along line III-III in FIG. 4 is a perspective view of a developing sleeve of the developing device 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. The units corresponding to the colors of yellow, magenta, cyan, and black are indicated by adding 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 (described later) of the transfer unit 104 and a photosensitive drum 108 of a developing device 113 (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 the sandwiched recording paper 107 can be superimposed on the toner image. Send out in 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 conveyance belt 129 circulates (endless travel) around the driving roller 127 and the driven roller 128 described above in the counterclockwise direction in the drawing as the driving roller 127 is rotationally driven.

  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 the 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 in parallel 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, and a photosensitive drum as an electrostatic latent image carrier (also referred to as an image carrier). 108, a cleaning blade 112 as a cleaning device, and a developing device 113. 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 gap from a developing roller 115 (to be 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 developing roller 115 as a developer carrier, 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 in both the first space 120 and the second space 121. The developer contains toner and a magnetic carrier (also called magnetic powder, whose cross section is shown in FIG. 9) 135. The toner is appropriately supplied to one end portion of the first space 120 on the side away from the developing roller 115 in the first space 120 and the second space 121. 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. 9, the magnetic carrier 135 includes a core material 136, a resin coat film 137 that covers 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 developing roller 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 from one end to the other end. The agitation screw 118 in the second space 121 conveys the developer from the other end to 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 developing roller 115 while transporting them 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 developing roller 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 developing roller 115 is formed in a cylindrical 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 developing roller 115 is parallel to both the photosensitive drum 108 and the storage tank 117. The developing roller 115 is disposed at a distance from the photosensitive drum 108.

  As shown in FIGS. 2 and 3, the developing roller 115 includes a cored bar 134, a cylindrical magnet roller (also referred to as a magnet body) 133, and the above-described cylindrical developing sleeve 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 magnet roller 133 is accommodated (enclosed) in the developing sleeve 132. As shown in FIGS. 5 and 6, the magnet roller 133 includes a cylindrical roller main body 140 as a cylindrical magnet molded body and two magnet blocks 141 as long magnet molded bodies.

  The roller body 140 is made of a magnetic material, is formed in a cylindrical shape, and is fixed to the outer periphery of the cored bar 134 without rotating around the axis. The roller body 140 is manufactured by injection molding and extrusion molding. The roller body 140 often uses a plastic magnet or a rubber magnet obtained by mixing a polymer compound with magnetic powder containing Sr or Ba as a raw material. The roller body 140 is made of a high molecular weight compound such as 6PA or 12PA, an ethylene compound such as EEA (ethylene / ethyl copolymer) / EVA (ethylene / vinyl copolymer), or CPE (chlorinated). Polyethylene) and other chloric materials, and NBR and other rubber materials can be used.

  As shown in FIGS. 5 and 6, the roller main body 140 is provided with two grooves 142 and a fixed magnetic pole (not shown). Of course, the two grooves 142 are formed in a concave shape from the outer peripheral surface of the roller main body 140 and have a rectangular cross section. The groove 142 extends linearly along the longitudinal direction of the roller body 140 and is provided over the entire length of the roller body 140.

  One groove 142 (hereinafter denoted by reference numeral 142a) of the two grooves 142 is provided at a position facing the photosensitive drum 108 (that is, a portion corresponding to a developing area 131 described later). The other groove 142 (hereinafter, indicated by reference numeral 142b) is adjacent to the downstream side of the rotation direction R (indicated by an arrow in FIG. 5) of the developing sleeve 132 of the one groove 142a (that is, the developing region 131) described above. It arrange | positions at a part and adjoins this one groove | channel 142a at intervals. Further, the other groove 142b is disposed between the one groove 142a and one fixed magnetic pole described later. The other groove 142b is a second groove described in the claims.

  The fixed magnetic pole provided on the roller body 140 is formed by correcting a part of the roller body 140 to the N pole or the S pole. The fixed magnetic pole extends along the longitudinal direction of the roller body 140 and is provided over the entire length of the roller body 140.

  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 developing sleeve 132, that is, the developing roller 115, so that the developer in the second space 121 of the storage tank 117 is removed from the developing sleeve 132. Adsorb to the surface.

  At least one fixed magnetic pole is provided between the above-described pumping magnetic pole and the above-described grooves 142a and 142b. The at least one fixed magnetic pole generates a magnetic force on the outer surface of the developing sleeve 132, that is, the developing roller 115, and conveys the developer before development toward the photosensitive drum 108.

  When the developer is attracted to the outer surface of the developing sleeve 132, the fixed magnetic pole described above and the magnet block 141 to be described later are overlapped with each other along the lines of magnetic force generated by the fixed magnetic pole. Standing on the outer surface of the head. In this manner, a state in which a plurality of magnetic carriers 135 are erected on the outer surface of the developing sleeve 132 along the lines of magnetic force is referred to as the magnetic carrier 135 rising on the outer surface of the developing sleeve 132. Then, the above-described toner is adsorbed to the magnetic carrier 135 that is raised. That is, the developing sleeve 132 attracts the developer to the outer surface by the magnetic force of the magnet roller 133.

  Two magnet blocks 141 are provided. The magnet block 141 is formed in a long bar shape. The magnet block 141 is embedded in the grooves 142a and 142b, fixed to the inner surfaces of the grooves 142a and 142b with an adhesive or the like, and attached to the roller body 140. The magnet block 141 extends linearly along the longitudinal direction of the roller body 140, that is, the magnet roller 133, and is provided over the entire length of the roller body 140, that is, the magnet roller 133.

  One magnet block 141 (hereinafter denoted by reference numeral 141 a) is embedded in the above-described one groove 142 a and attached to the roller body 140. One magnet block 141a is opposed to the photosensitive drum 108 described above. The one magnet block 141 a forms a developing magnetic pole, and generates a magnetic force on the developing sleeve 132, that is, the outer surface of the developing roller 115, thereby forming a magnetic field between the developing sleeve 132 and the photosensitive drum 108. The one magnet block 141 a forms a magnetic brush by the magnetic field so as to deliver the developer toner adsorbed on the outer surface of the developing sleeve 132 to the photosensitive drum 108. As described above, one magnet block 141a has a developing region 131 (shown in FIG. 5) for transferring the developer toner adhering to the outer surface of the developing sleeve 132 to the photosensitive drum 108. To form.

  The other magnet block 141 (hereinafter denoted by reference numeral 141 b) is embedded in the other groove 142 b described above and attached to the roller body 140. The other magnet block 141b is located downstream in the rotation direction R of the developing sleeve 132 of the one magnet block 141a, that is, in the developer transport direction, and is disposed between the one magnet block 141a and the pumping magnetic pole. The other magnet block 141 b conveys the developed developer from the photosensitive drum 108 to the inside of the storage tank 117.

  The magnet blocks 141a and 141b are obtained by filling compression molding magnet compounds 150A and 150B shown in FIGS. 17 and 18 into a press mold in a magnetic field and compression molding. That is, the magnet blocks 141a and 141b are obtained by compression molding the compression molding magnet compounds 150A and 150B in a magnetic field. In this compression molding, since the amount of the binding resin can be at least molded, the blending ratio of the magnetic powder 151 described later can be increased. Moreover, since the molding density of the magnet blocks 141a and 141b can be increased by compression molding, it is an excellent method for increasing the magnetic force.

  As shown in FIGS. 17 and 18, the compression molding magnet compounds 150 </ b> A and 150 </ b> B have magnetic powder 151 composed of magnetic particles 152 having a rounded average particle diameter of 100 to 200 μm and thermoplastic resin fine particles 153. is doing. In the compression molding magnet compound 150B, at least a part of the surface of the magnetic particle 152 has a coating layer 154 composed of a polyurethane resin or a condensation crosslinked product of a polyurethane resin and an amino resin. As described above, when the compression molding magnet compounds 150A and 150B have the magnetic powder 151 and the thermoplastic resin fine particles 153, friction is caused when the magnetic particles 152 and the thermoplastic resin fine particles 153 are stirred and mixed. The charging causes the magnetic particles 152 to be positively charged and the thermoplastic resin fine particles 153 to be negatively charged. For this reason, the thermoplastic resin fine particles 153 are attached to the surface of the magnetic particles 152 by electrostatic adhesion. Therefore, the orientation of the magnetic particles 152 in the molded magnet blocks 141a and 141b is improved, and the magnetic characteristics of the magnet blocks 141a and 141b are improved.

  Further, like the compression molding magnet compound 150B shown in FIG. 18, at least a part of the surface of the magnetic particle 152 is made of a polyurethane resin or a condensation crosslinked product of a polyurethane resin and an amino resin. 154, the thermoplastic resin fine particles 153 are likely to be negatively charged, and the polyurethane resin or a condensation crosslinked product of the polyurethane resin and the amino resin is easily positively charged. The electrostatic adhesion force between the resin fine particles 153 and the polyurethane resin or the condensation crosslinked product of the polyurethane resin and the amino resin is increased. Therefore, due to the load applied when the compression molding magnet compound 150B is filled in the mold. The thermoplastic resin fine particles 153 are almost free and scattered. Thus, the magnetic properties of the magnetic blocks 141a and 141b can be improved by increasing the orientation of the magnetic particles 152 in the orientation magnetic field, and the magnetic blocks 141a and 141b can be reduced in variation in magnetic flux density. The thermal demagnetization at the time can be suppressed.

  The blending ratio of the magnetic powder 151 in the compression molding magnet compounds 150A and 150B in the present invention is preferably 90 to 99 wt%, and more preferably 92 to 97 wt%. If the content of the magnetic powder 151 is too small, the magnetic properties cannot be improved, and if the content of the magnetic powder is too large, the content of the binding resin is reduced and the moldability of the magnet blocks 141a and 141b is lowered. (Breakage etc.).

As shown in FIG. 16, the magnetic powder 151 of the present invention is composed of magnetic particles 152 having a rounded average particle diameter of 100 to 200 μm. The bulk density thereof is adjusted to ^{3.3g / cm 3 ~4.0g / cm 3} . In the present specification, the “bulk density” is obtained by filling a pile of 485 g of magnetic powder into a 100 cc metal container through a funnel and scraping it along the upper surface of the container. The measured weight is divided by the volume of 100 cc.

Thus, a magnetic powder 151 made of a magnetic particle 152 take corners, the bulk density of which is adjusted to ^{3.3g / cm 3 ~4.0g / cm 3} , there a high magnetic force And even if it is long, it can be set as the magnet blocks 141a and 141b by the compression molding which made the dispersion | variation in magnetic flux density small.

The bulk density is the magnetic powder 151 is adjusted to ^{3.3g / cm 3 ~4.0g / cm 3} , the collision of the magnetic particles 152 together with angular, or, than the magnetic particles strung angular magnetic particles 152 angular It is formed by collision with particles (not shown) made of a high hardness substance. Thus, the bulk density is the magnetic powder 151 is adjusted to ^{3.3g / cm 3 ~4.0g / cm 3} , the collision of the magnetic particles 152 each other angular or stretched angular magnetic particles 152 angular When formed by collision with particles composed of a substance having a hardness higher than that of magnetic particles, the corners of each magnetic powder before adjustment are easily removed, resulting in a shape close to a sphere (see FIG. 16). , Therefore, also the bulk density of the pre-adjustment of the magnetic powder is not more 3.3 g / cm ³ or less, the magnetic powder 151 bulk density is adjusted to 3.3g / cm ³ ~4.0g / cm ³ easily Can get to.

Since the magnetic powder 151 of the present invention has a large contact area between the magnetic particles 152 having an average particle size of 100 to 200 μm constituting the magnetic powder 151, the bulk density is increased. The inventors of the present invention have a close relationship between the bulk density of the magnetic powder 151 and the magnetic flux density of the magnet blocks 141a and 141b, and that the magnetic flux density of the magnet blocks 141a and 141b increases as the bulk density increases. I found it. As described above, the magnetic flux density of the magnet blocks 141a and 141b increases as the bulk density increases. The magnet blocks 141a and 141b are formed by closely filling the mold with magnetic particles 152 having an average particle diameter of 100 to 200 μm. At the same time, since the magnetic particles 152 have a shape close to a sphere, the rotation of the magnetic powder 151 during magnetic field orientation is difficult to be obstructed and the directions of easy magnetization axes are easily aligned. It is. When the bulk density of the magnetic powder 151 is less than 3.3 g / cm ³ , a predetermined high magnetic flux density cannot be obtained, and when the bulk density of the magnetic powder 151 exceeds 4.0 g / cm ³ , It cannot be obtained with technology. Therefore, as in the present invention, the bulk density of the magnetic powder 151 is the is ^{3.3g / cm 3 ~4.0g / cm 3} , a predetermined high magnetic flux density can be obtained.

In general, a regrind of the magnetic powder 151 uses a grinder such as an attritor grinder or a jet mill grinder and a stirrer such as a Henschel mixer. However, since the pulverizer and the stirrer used for re-pulverization pulverize the magnetic particles 152 constituting the magnetic powder 151 finely, the average particle diameter of the magnetic particles 152 becomes small. Further, if the average particle size of the magnetic particles 152 is small, the magnetic characteristics are deteriorated, which is not preferable. Further, since the amount of fine powder is increased by re-grinding, the fluidity of the magnetic powder 151 is lowered, and therefore the filling property into the mold is lowered. In order to improve the density of the magnetic powder 151 while eliminating such problems, the magnetic particles 152 or a mixture of the magnetic particles 152 and the media are stirred using a tumbler mixer as in the present invention. Is the most effective means. The true specific gravity of the rare earth magnet powder is about 7.5 g / cm ³ , and the theoretical upper limit is this value, but in reality, what exceeds 4.0 g / cm ³ cannot be obtained with the current technology.

  The magnetic powder 151 in the present invention is composed of magnetic particles 152 made of a rare earth magnetic material capable of increasing the magnetic force (13 MGOe or more). The rare earth magnetic body in the present invention is preferably the following 1) to 3) made of an alloy containing a rare earth element and a transition metal, with 1) being particularly preferred.

1) R (where R is at least one of rare earth elements including Y), transition metal mainly composed of Fe, and B as basic components (referred to as R—Fe—B alloy) What) Typical examples include Nd—Fe—B alloys, Pr—Fe—B alloys, Nd—Pr.
-Fe-B alloy, Ce-Nd-Fe-B alloy, Ce-Pr-Nd-Fe-B alloy, and a part of Fe in them were replaced with other transition metals such as Co and Ni Things can be raised.

2) A rare earth element mainly composed of Sm and a transition metal mainly composed of Co (basic components are referred to as Sm-Co alloys). Typical examples include SmCo ₅ and Sm ₂ TM ₁₇ (TM is a transition metal).

3) A rare earth element mainly composed of Sm, a transition metal mainly composed of Fe, and an interstitial element mainly composed of N (what is called an Sm-Fe-N alloy) . A typical example is Sm ₂ Fe ₁₇ N ₃ produced by nitriding Sm ₂ TM ₁₇ alloy.

  Examples of the rare earth elements include Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Misch metal, and the like. Species or two or more can be included. Examples of the transition metal include Fe, Co, Ni, and the like, and one or more of these can be included. Further, in order to improve the magnetic characteristics, the magnetic powder 151 may contain B, Al, Mo, Cu, Ga, Si, Ti, Ta, Zr, Hf, Ag, Zn, or the like, if necessary. .

  The volume average particle diameter of the magnetic particles 152 constituting the magnetic powder 151 of the present invention is preferably 100 to 200 μm, and more preferably 120 to 170 μm. The average particle diameter is measured by a DRY unit of Mastersizer 2000 manufactured by Sysmex Corporation.

  As shown in FIG. 18, at least a part of the surface of the magnetic particles 152 constituting the magnetic powder 151 has a coating layer 154 composed of a polyurethane resin or a condensation crosslinked product of a polyurethane resin and an amino resin. Have. Thus, when at least a part of the surface of the magnetic particles 152 constituting the magnetic powder 151 has a coating layer 154 composed of a polyurethane resin or a condensation crosslinked product of a polyurethane resin and an amino resin, When the compression molding magnet compound 150B is used, the condensation crosslinking product of the polyurethane resin or polyurethane resin and amino resin is easily positively charged, and the magnetic particle 152 having the coating layer 154 becomes a binding resin. The electrostatic adhesive force with the thermoplastic resin fine particles 153 becomes stronger, and therefore, the thermoplastic resin fine particles 153 may be scattered and scattered by the load applied when the compression molding magnet compound 150B is filled in the mold. Almost disappear.

  The average particle diameter of the thermoplastic resin fine particles 153 in the compression molding magnet compounds 150A and 150B is preferably 1/10 or less of the average particle diameter of the magnetic particles 152 of the magnetic powder 151. Thus, when the average particle diameter of the thermoplastic resin fine particles 153 in the compression molding magnet compounds 150A and 150B is 1/10 or less of the magnetic particles 152 of the magnetic powder 151, the molding density of the magnet compact is increased. Therefore, the magnetic properties can be improved.

  The thermoplastic resin fine particles 153 in the compression molding magnet compounds 150A and 150B are preferably spherical fine particles produced by an emulsion polymerization method or a suspension polymerization method. As described above, when the thermoplastic resin fine particles 153 in the compression molding magnet compounds 150A and 150B are spherical fine particles produced by an emulsion polymerization method or a suspension polymerization method, it is possible to increase the density of the compression molded product. Therefore, the magnetic characteristics can be further improved. In addition, when the spherical fine particles are formed in this manner, the area covered with the magnetic powder is improved, so that the exposed area of the magnetic powder on the surface of the magnet molded body can be reduced, and thus a rust prevention effect is produced.

  The “thermoplastic resin” constituting the “thermoplastic resin fine particles 153” includes, for example, a styrene compound such as polystyrene, polychloroethylene, polyvinyltoluene and the like, a homopolymer composed of a substituted product thereof, and styrene-p-chloro. Styrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-acrylic acid Butyl copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer Polymer, styrene-acrylonitrile polymer, steel -Vinyl methyl ether polymer, styrene-vinyl methyl ketone polymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic Examples thereof include styrene copolymers such as acid ester copolymers. The “thermoplastic resin” includes polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyvinyl butyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenol. A resin such as a resin or an epoxy polyol resin may be used. These resins can be used alone or in combination.

  As described above, the “thermoplastic resin fine particles 153” are used as a binding resin (binder). For example, a thermoplastic resin such as polyester or polyol, a charge control agent (CCA), a pigment, A low softening point substance (wax) is dispersed and mixed, and a substance such as silica or titanium oxide is externally added to improve the fluidity. The addition amount of the pigment is 1 to 20 wt%, preferably 5 to 10 wt%. The charge control agent is added to improve the dispersibility of the magnet particles and the thermoplastic resin fine particles. The addition amount of the charge control agent is 1 to 20 wt%, preferably 0.5 to 10 wt%. The mold release agent is added to improve mold release properties after molding. The addition amount of the release agent is 1 to 20 wt%, preferably 2 to 10 wt%. The “thermoplastic resin fine particles 153” are easily negatively charged and excellent in fluidity, and thus have excellent electrostatic adhesion with the magnetic powder and can sufficiently fill the gaps between the magnet particles.

  For example, aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, and zinc oxide are used as external additives in the “thermoplastic resin fine particles 153”. Examples thereof include nitrides such as silicon, carbides such as silicon carbide, metal salts such as calcium sulfate, barium sulfate, and calcium carbonate, fatty acid metal salts such as zinc stearate and calcium stearate, carbon black, and silica. The particle size of the external additive is usually in the range of 0.1 to 1.5 μm, and the addition amount is preferably 0.01 to 10 parts by weight, more preferably 100 parts by weight before external addition, 0.05 to 5 parts by weight. These external additives may be used alone or in combination. These external additives are preferably those subjected to a hydrophobic treatment.

  Examples of the “pigment” include carbon black, lamp black, magnetite, titanium black, chrome yellow, ultramarine blue, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G, rhodamine 6G, calco oil blue, quinacridone, and benzidine. Yellow, Rose Bengal, Malachite Green Lake, Quinoline Yellow, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 184, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 180, C.I. I. Solvent Yellow 162, C.I. I. Pigment blue 5: 1, C.I. I. Pigment blue 15: 3, carmine and the like.

  Further, the “thermoplastic resin fine particles 153” may be internally added with a low softening substance. Examples of such a low softening substance include paraffin wax, polyolefin wax, Fischer tropish wax, amide wax, higher fatty acid, ester wax and derivatives thereof, or graft / block compounds thereof. When adding such a low softening substance, it is preferable to add about 5-30 mass%.

  As described above, the magnet blocks 141a and 141b are made of a material containing rare earth elements and are formed in a long rod shape, so that the attenuation factor of the magnetic flux density in the normal direction is formed to be 40% or more. ing. The attenuation rate is a method based on the outer surface relative to the magnetic flux density on the outer surface of the developing sleeve 132 at the highest magnetic flux density in the magnetic field formed on the outer surface of the developing sleeve 132 by the magnet blocks 141a and 141b. The attenuation rate of the magnetic flux density at a position 1 mm away along the linear direction (the radial direction of the developing sleeve 132) is shown.

  More specifically, the magnet blocks 141a and 141b have a higher magnetic force (13 to 16 MGOe) than a conventional plastic magnet having a maximum magnetic flux density of 100 to 130 mT and a maximum magnetic flux density of 80 to 120 mT. Furthermore, one magnet block 141a has a half-value width of 25 degrees or less, and the half-value width is narrower than that of a conventional plastic magnet having a half-value width of about 50 degrees. In addition, this half value width has shown the angle of the part used as magnetic flux density more than half of the maximum magnetic flux density. In this way, at least one of the magnet blocks 141a is formed in a long length so as to include the rare earth element so that the above-described half-value width is narrower than that of the conventional product, so that the above-described attenuation rate becomes 40% or more. ing. As described above, the magnet blocks 141a and 141b having the attenuation rate of 40% according to the present invention include those which are formed long so as to include the rare earth element and have the half width as described above. Show.

  Furthermore, as described above, the magnet blocks 141a and 141b contain rare earth elements, and thus are formed with a higher magnetic force than the roller body 140 described above.

  As shown in FIG. 4, the developing sleeve 132 is formed in a cylindrical shape. The developing sleeve 132 includes (accommodates) a magnet roller 133 and is provided so as to be rotatable around the axis. The developing sleeve 132 is rotated so that the inner peripheral surface thereof is sequentially opposed to the fixed magnetic pole. The developing sleeve 132 is made of a nonmagnetic material such as an aluminum alloy or stainless steel (SUS). As described above, the developing sleeve 132 is roughened on the outer surface by the surface treatment apparatus 1.

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

Further, as shown in FIGS. 7 and 8, the outer surface of the developing sleeve 132 is provided with a number of recesses 139 having an elliptical planar shape. A large number (a plurality) of the recesses 139 are randomly arranged on the outer surface of the developing sleeve 132. Of course, the recess 139 includes a recess 139 whose longitudinal direction is along the axial direction of the developing sleeve 132 and a recess 139 whose longitudinal direction is along the circumferential direction of the developing sleeve 132. The number of the recesses 139 whose longitudinal direction is along the axial direction of the developing sleeve 132 is greater than the number of the recesses 139 whose longitudinal direction is along the circumferential direction of the developing sleeve 132. Furthermore, the length (major axis) in the longitudinal direction of the recess 139 is 0.05 mm or more and 0.3 mm or less, and the width ( minor axis ) in the width direction is 0.02 mm or more and 0.1 mm or less. It has become. 7 and 8, the left-right direction in the drawing is the axial direction of the developing sleeve 132.

  The regulating blade 116 is provided at the end 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 developing sleeve 132. The regulating blade 116 removes the developer on the outer surface of the developing sleeve 132 exceeding the desired thickness into the storage tank 117, and the developer on the outer surface of the developing sleeve 132 conveyed to the developing region 131 is desired. Of 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 is adsorbed to the outer surface of the developing sleeve 132 by the fixed magnetic pole. In the developing device 113, the developing sleeve 132 rotates, and the developer adsorbed by the plurality of fixed magnetic poles is conveyed toward the developing region 131. The developing device 113 adsorbs the developer having a desired thickness by the regulating blade 116 to the photosensitive drum 108. Thus, the developing device 113 carries the developer on the developing roller 115 and transports it to the developing area 131 to develop the electrostatic latent image on the photosensitive drum 108 to form a toner image.

  Then, the developing device 113 releases the developed developer toward the storage tank 117. Further, the developed developer stored in the storage tank 117 is sufficiently stirred again with another developer in the second space 121 to develop the electrostatic latent image on the photosensitive drum 108. Used.

  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 adsorbed on the outer surface of the developing sleeve 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 paper 107 conveyed by the paper supply roller 124 of the paper supply unit 103 is transferred to the photosensitive drum 108 of the process cartridges 106Y, 106M, 106C, and 106K and the conveyance 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.

  The developing sleeve 132 described above is subjected to a roughening process on the outer surface by the surface treatment apparatus 1 shown in FIGS.

  As shown in FIG. 10, the surface treatment apparatus 1 includes a base 3, a fixed holding unit 4, an electromagnetic coil moving unit 5 as a moving means, a moving holding unit 6, a moving chuck unit 7, and a magnetic field generating unit. The electromagnetic coil 8, the storage tank 9, the collection | recovery part 10, the cooling part 11, the linear encoder 75 as a detection means, and the control apparatus 76 (shown in FIG. 11) as a control means 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 a cylindrical developing sleeve 132 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 so that the developing sleeve 132 is parallel to the longitudinal direction of the storage tank 9, that is, the axis of the hollow holding member 32, that is, the axis of the developing sleeve 132 is centered. Rotate as.

  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 developing sleeve 132 are fixed by pressing against the inner peripheral surface of the developing sleeve 132. At this time, of course, the chuck shaft 39, the hollow holding member 32, the developing sleeve 132, and the cylindrical member 50 described later, that is, the storage tank 9 are coaxial.

  The chuck cylinder 34 and the chuck pawl 40 described above hold the developing sleeve 132 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 hold the developing sleeve 132 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 described in the claims.

  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. 11, 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 power that is shifted from each other, and the plurality of coil portions 47 generate magnetic fields that are 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. The electromagnetic coil 8 positions the wire material 65 housed in the housing tank 9 on the outer periphery of the developing sleeve 132 by the rotating magnetic field described above, and the wire material 65 is positioned on the axis of the housing tank 9 and the developing sleeve 132. Rotate (move) around. Then, the electromagnetic coil 8 causes the linear material 65 moved by the above-described rotating magnetic field to collide with the outer surface of the developing sleeve 132.

  Further, an inverter 49 as a magnetic field changing unit 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 as a magnetic field changing unit. 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. 11, 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 shavings 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 51b) among the plurality of flange members 51 attached to the one end 9a 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 is formed on the outside of the cylindrical member 50, that is, the storage tank 9, when the wire 65 described later collides with the outer surface of the developing sleeve 132, and the shavings formed by scraping off the developing sleeve 132. Regulate leaking.

  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 position the developing sleeve 132 on the hollow holding member 32 with the developing sleeve 132 interposed therebetween. 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 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 axis of the cylindrical member 50, that is, the storage tank 9, that is, the axis P of the developing sleeve 132. 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 a cap 64 (described later) attached to both ends of the developing sleeve 132 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 configured as described above stores the linear member 65 made of a magnetic material between the plurality of partition members 55, and stores the developing sleeve 132 attached to the hollow holding member 32 in the cylindrical member 50. . That is, the storage tank 9 stores both the developing sleeve 132 and the wire material 65. Further, the linear member 65 collides with the outer surface of the developing sleeve 132 by rotating (moving) the outer periphery of the developing sleeve 132 by the rotating magnetic field described above. The linear member 65 collides with the outer surface of the developing sleeve 132, scrapes a part of the developing sleeve 132 from the outer surface of the developing sleeve 132, and roughens the outer surface of the developing sleeve 132.

  The wire rod 65 is made of a magnetic material such as austenitic stainless steel or martensitic stainless steel. As shown in FIG. 12, the wire rod 65 is formed in a short cylindrical shape. The wire rod 65 has an outer diameter of 0.5 mm or more and 1.2 mm or less. The wire 65 is formed such that L / D is 4 or more and 10 or less, where L is the total length and D is the outer diameter.

  Furthermore, as shown in FIG.12 and FIG.13, the outer edge part 65a of the both ends of the wire rod 65 is given the chamfering process of circular arc cross section over the perimeter. The radius of curvature R of the outer edge portion 65a is 0.05 mm or more and 0.2 mm or less.

  As shown in FIG. 14, the wire 65 described above is rotated (rotated) around the center in the longitudinal direction by the rotating magnetic field as described above, while rotating in the circumferential direction of the container 9 and the developing sleeve 132 ( Revolved).

  As shown in FIG. 11, 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. 10). . 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. 10, 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. 11, 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. As described above, the linear encoder 75 detects the relative position of the electromagnetic coil 8 with respect to the storage tank 9, that is, the developing sleeve 132, and outputs the detection result to 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 developing sleeve 132. In other words, 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 developing sleeve 132. Further, the control device 76 stores the power described above for each product number of the developing sleeve 132.

  In the illustrated example, the control device 76 has a pattern in which the electric power applied by the inverter 49 to the electromagnetic coil 8 gradually increases as the electromagnetic coil 8 moves from the central portion in the longitudinal direction (axial direction) of the developing sleeve 132 toward both ends. 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. Thus, in the illustrated example, the control device 76 controls the inverter 49 so that the rotating magnetic field when processing both ends of the developing sleeve 132 is stronger than the rotating magnetic field when processing the central portion of the developing sleeve 132. The strength of the magnetic field generated by the electromagnetic coil 8 is changed. As described above, the control device 76 determines the strength of the rotating 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 developing sleeve 132. Change the size.

  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 developing sleeve 132 by processing (roughening) the outer surface of the developing sleeve 132 using the surface processing apparatus 1 having the above-described configuration will be described below.

  First, the product number of the developing sleeve 132 and the like are input to the control device 76 from the input device. Then, cylindrical caps 64 are fitted to the outer circumferences at both ends in the longitudinal direction (axial direction) of the developing sleeve 132. 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 developing sleeve 132 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 developing sleeve 132 is fixed to the hollow holding member 32. At this time, the hollow holding member 32 and the developing sleeve 132 are coaxial. In this way, the developing sleeve 132 is attached to the hollow holding member 32.

  The developing sleeve 132 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. Thus, the wire 65 and the developing sleeve 132 are accommodated in the accommodating tank 9. Further, the storage tank 9 is chucked by the holding chucks 28 and 43. In this way, the developing sleeve 132 and the storage tank 9 are attached to the movable holding unit 6. Then, the cylindrical member 50, the hollow holding member 32, the developing sleeve 132, 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 developing sleeve 132 is rotated about 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 material 65 located inside the electromagnetic coil 8 revolves (rotates or moves) around the axis P while rotating, and the wire material 65 collides with the outer surface of the developing sleeve 132, The outer surface of the developing sleeve 132 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 developing sleeve 132 ends.

  Further, the rotating magnetic field generated by the electromagnetic coil 8 becomes stronger as the electromagnetic coil 8 moves from the central portion of the developing sleeve 132 toward both ends. As the rotating magnetic field becomes stronger, the movement of the filament material 65 becomes more intense. Then, as the rotating magnetic field becomes stronger, the wire rod 65 collides with the object to be processed more vigorously, and the surface roughness of the outer surface of the developing sleeve 132 becomes more rough.

  When the above-described roughening of the outer surface of the developing sleeve 132 is completed, the application of electric power to the electromagnetic coil 8 is stopped and the driving 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 developing sleeve 132 whose outer surface has been roughened is taken out of the storage tank 9, and a new developing sleeve 132 is stored in the storage tank 9. In this way, the developing sleeve 132 (shown in FIG. 4) is obtained in which the outer surface of the developing sleeve 132 is roughened so that the outer surface becomes gradually rougher from the center toward both ends.

  In addition, as shown in FIG. 14, the wire 65 rotates around the central portion in the longitudinal direction with the longitudinal direction along the radial direction of the housing 9 and the developing sleeve 132, as shown in FIG. The outer periphery of the developing sleeve 132 is revolved. For this reason, as shown by a solid line in FIG. 15, the outer edge portion 65 a of the linear member 65 collides with the outer surface of the developing sleeve 132. Then, as shown in FIGS. 7 and 8, a large number of substantially elliptical (oval) shaped recesses 139 are randomly formed on the outer surface of the developing sleeve 132. In addition, the substantially elliptical (oval) shaped recess 139 formed on the outer surface of the developing sleeve 132 has a longer longitudinal direction along the axial direction of the developing sleeve 132 than a circumferential direction of the developing sleeve 132.

  According to the present embodiment, an oval-shaped recess 139 (longer diameter is 0.05 mm or more and 0.3 mm or less, short diameter is much larger than the recess formed by conventional sandblasting on the outer surface of the developing sleeve 132. Is 0.02 mm or more and 0.1 mm or less). For this reason, it becomes difficult for the dent 139 to be worn by secular change. Therefore, it is possible to suppress a decrease in the transport amount of the developer due to aging.

  Further, the developing sleeve 132 is randomly arranged with oval dents 139 formed on the outer surface. For this reason, since the developer accumulates in the recess 139, the places where the developer accumulates are randomly arranged on the outer surface. Therefore, it is possible to prevent image unevenness.

  In addition, since the high magnetic force magnet block 141 containing rare earth elements is embedded in the portion corresponding to the developing area 131 of the roller body 140, the developing ability is good and the occurrence of white spots on the formed image is prevented. it can.

  Since a magnet block 141 containing a rare earth element and having a high magnetic force is embedded in an adjacent portion downstream of a portion corresponding to the developing region 131 of the roller body 140, a magnetic carrier 135 of developer is attached to the outer surface of the developing sleeve 132. The magnetic carrier 135 can be prevented from adhering to the photosensitive drum 108.

  Since the magnet blocks 141a and 141b formed by compression-molding the compression molding magnet compounds 150A and 150B in a magnetic field are provided, the concentration of the binding resin can be reduced to obtain the magnet blocks 141a and 141b having a large magnetic property. Therefore, high magnetic force magnet blocks 141a and 141b of 13 MGOe or more (100 mT or more) can be obtained. Therefore, it is possible to obtain the developing roller 115 having a good developing ability.

Since the bulk density of the magnetic powder 151 is adjusted to ^{3.3g / cm 3 ~4.0g / cm 3} , at the time of molding, the magnetic grains 152 of the magnetic powder 151 is densely packed, magnet block 141a, 141b Since the density of the magnetic powder 151 can be increased, the magnet blocks 141a and 141b having high magnetic force are obtained.

  Since the average particle size of the thermoplastic resin fine particles 153 is 1/10 or less of the magnetic particles 152 of the magnetic powder 151, the gap between the magnetic particles 152 of the magnetic powder 151 is filled with the thermoplastic resin fine particles 153, and the magnet The molding density of the blocks 141a and 141b can be increased, and therefore the magnetic characteristics of the magnet blocks 141a and 141b can be improved.

  Since the thermoplastic resin fine particles 153 are spherical fine particles produced by an emulsion polymerization method or a suspension polymerization method, it is possible to increase the density of the compression-molded product, thereby further improving the magnetic properties. Further, when the spherical particles are used, the coverage area of the magnetic powder 151 on the magnetic particles 152 is improved, so that the exposed area of the magnetic particles 152 of the magnetic powder 151 on the surfaces of the magnet blocks 141a and 141b can be reduced. An effect is produced.

  Further, since the number of the recesses 139 whose longitudinal direction is along the axial direction of the developing sleeve 132 is larger than the recesses 139 whose longitudinal direction is along the circumferential direction of the developing sleeve 132, the developer 126 to be pumped up is aligned along the axial direction of the developing sleeve 132. Will be installed. For this reason, even if the developing sleeve 132 rotates, the pumped developer is unlikely to fall off from the outer surface of the developing sleeve 132. Therefore, the oval-shaped recess 139 can achieve the same effect as the V-groove that has been conventionally used, and the amount of developer to be pumped can be ensured.

  Further, since the wire 65 is randomly collided with the outer surface to form the elliptical recess 139, the axial center of the developing sleeve 132 is curved, the inner and outer diameters are changed, and the cross-sectional shape is elliptical. Can be prevented. In other words, the deflection accuracy of the developing sleeve 132 can be kept high.

  Further, random irregularities are formed on the developing sleeve 132. Therefore, unevenness in the amount of developer supplied to the photosensitive drum 108 can be prevented, and unevenness in density can be prevented from occurring in the formed image.

  Since the linear material 65 positioned in the rotating magnetic field collides with the outer surface of the developing sleeve 132, the linear material 65 collides with the outer surface of the developing sleeve 132 more randomly. Therefore, more uniform unevenness can be formed on the outer surface of the developing sleeve 132, and a more uniform image can be obtained.

  Further, since the irregularities can be formed on the outer surface of the developing sleeve 132 by positioning the linear member 65 in the rotating magnetic field, it is possible to prevent an increase in the number of steps when forming the irregularities on the outer surface of the developing sleeve 132. Therefore, it is possible to prevent the process for forming the unevenness on the outer surface of the developing sleeve 132 from becoming complicated, and it is possible to prevent the processing cost from rising.

  Further, by positioning the linear member 65 in the rotating magnetic field, irregularities can be formed on the outer surface of the developing sleeve 132, so that the longitudinal direction of the linear member 65 extends in the radial direction of the rotating magnetic field. The outer periphery of the developing sleeve 132 revolves while rotating around the center of the direction. For this reason, the outer edge portions at both ends in the longitudinal direction of the linear member 65 collide with the developing sleeve 132, and the concaves and recesses 139, which are formed on the outer surface of the developing sleeve 132, become the shaft (longitudinal) of the developing sleeve 132. ) More along the direction. For this reason, the dent 139 formed on the outer surface of the developing sleeve 132 reliably exhibits the same effect as the V-groove that has been conventionally used, and the amount of developer pumped up can be ensured.

  Further, since the linear member 65 is randomly collided with the outer surface of the developing sleeve 132 by the rotating magnetic field, the unevenness formed on the outer surface of the developing sleeve 132 becomes more reliably random. Therefore, it is possible to prevent the image formed by the developing sleeve 132 from becoming uneven.

  Since the developing sleeve 132 is housed in the housing tank 9 together with the wire material 65, it reliably collides with the outer surface of the developing sleeve 132. Accordingly, it is possible to reliably perform the roughening process on the outer surface of the developing sleeve 132.

  Since the line material 65 collides with the developing sleeve 132 rotating in the storage tank 9, the line material 65 collides with the outer surface of the developing sleeve 132 even more randomly. Accordingly, the recesses 139 can be formed more uniformly while maintaining higher accuracy, and an image with less unevenness can be obtained.

  According to the image forming apparatus 101 described above, since the developer having an average particle diameter of 20 μm or more and 35 μm or less of the magnetic carrier 135 is used, an excellent image with excellent granularity and little unevenness can be obtained. If the average particle size of the magnetic carrier 135 is less than 20 μm, the magnitude of the magnetization of each magnetic carrier 135 becomes small, so the magnetic binding force of the magnetic carrier 135 from the developing roller 115 becomes weak, and the magnetic carrier 135 Since the carrier 135 is easily attracted to the photosensitive drum 108, it is not desirable. If the average particle size of the magnetic carrier 135 exceeds 35 μm, the electric field between the magnetic carrier 135 and the electrostatic latent image on the photosensitive drum 108 becomes sparse, so that a uniform image cannot be obtained (the image quality deteriorates). Therefore, it is not desirable.

  In addition, since the developing device 113 described above is included, it is possible to provide the process cartridges 106Y, 106M, 106C, and 106K and the image forming apparatus 101 that can obtain high-quality images over a long period of time.

  In addition, since the distance between the developing sleeve 132 and the photosensitive drum 108 is 0.1 mm or more and 0.4 mm or less, the toner can be reliably supplied to the photosensitive drum 108 from the developer that has risen on the developing sleeve 132. High quality images can be obtained. If the distance between the developing sleeve 132 and the photosensitive drum 108 is less than 0.1 mm, the electric field between the developing sleeve 132 and the photosensitive drum 108 becomes too strong, and the magnetic carrier 135 is formed on the photosensitive drum 108. It moves and is not desirable. If the distance between the developing sleeve 132 and the photosensitive drum 108 exceeds 0.4 mm, the electric field between the developing sleeve 132 and the photosensitive drum 108 becomes too weak, and the amount of toner that can be supplied to the photosensitive drum 108 is small. This decreases the development efficiency and increases the edge effect of the electric field at the edge of the image, making it impossible to obtain a uniform image.

  Further, a developer having a magnetic carrier 135 in which the surface of the core material 136 is coated with a resin coating film 137 in which a charge adjusting agent is contained in a resin component obtained by crosslinking a thermoplastic resin and a melamine resin is used. As described above, since the magnetic carrier 135 in which the core material 136 is coated with the resin coating film 137 having elasticity is used, the resin coating film has elasticity, so that the shock is absorbed and the magnetic carrier 135 is shaved. To prevent that. For this reason, it is possible to achieve a longer life than conventional magnetic carriers.

  Further, alumina particles 138 larger than the thickness of the resin coat film 137 are dispersed in the resin coat film 137 described above. As described above, the developer having the magnetic carrier 135 provided with the alumina particles 138 protruding from the outer surface of the resin coat film 137 is used. For this reason, the alumina particles 138 can prevent the resin coating film 137 from colliding and can clean the spent material.

  Therefore, since the resin coating film 137 can be prevented from being scraped, the life can be further prolonged as compared with the conventional magnetic carrier. Therefore, it is possible to obtain a stabilization rule of the pumping amount of toner, that is, high image quality over a long period of time.

  Since the toner is selected to be based on the emulsion polymerization method or suspension polymerization method, since the sphericity of the toner is good, there is an effect that the density unevenness remaining on the image is visually improved.

  Since the outer diameter D of the wire rod 65 is not less than 0.5 mm and not more than 1.2 mm, the unevenness formed on the outer surface of the developing sleeve 132 as the object to be processed becomes difficult to wear even with aging, and development The sleeve 132 can prevent the developer pumping amount from decreasing due to secular change. Accordingly, it is possible to prevent the image from becoming thin due to aging.

  Therefore, a linear strip that can be subjected to a roughening process on the outer surface of the developing sleeve 132 so as to suppress a decrease in the transport amount of the developer due to aging of the developing sleeve 132 and to prevent image unevenness. The material 65 and the surface treatment apparatus 1 can be provided.

  Further, since the ratio (L / D) between the total length L and the outer diameter D is 4 or more and 12 or less, the outer edge portions 65a at both ends in the longitudinal direction of the linear material 65 reliably collide with the developing sleeve 132. The full length of the line material 65 is sufficient to form unevenness having a sufficient depth (size) on the outer surface of the developing sleeve 132. Therefore, irregularities can be reliably formed on the outer surface of the developing sleeve 132, and the developer pumping amount of the developing sleeve 132 can be made a sufficient amount.

  Further, the outer edge portions 65a at both ends in the longitudinal direction of the linear member 65 are chamfered in a circular arc shape. For this reason, smooth irregularities can be formed on the outer surface of the developing sleeve 132 as the object to be processed, and the secular change of the developer, that is, the magnetic carrier 135 of the developing sleeve 132 can be prevented.

  Since the radius of curvature R of the cross-sectional shape of the outer edge portion 65a formed at both ends in the longitudinal direction of the wire rod 65 is 0.05 mm or more and 0.2 mm or less, the outer surface of the developing sleeve 132 as the processing object is outside. Smooth irregularities can be formed on the surface.

  Since the wire rod 65 is made of austenitic stainless steel or martensitic stainless steel, the wire rod 65 can be easily obtained, and the cost of the wire rod 65 can be reduced. .

  The control device 76 can change the strength of the rotating magnetic field generated by the electromagnetic coil 8 based on the relative position of the electromagnetic coil 8 with respect to the storage tank 9, that is, the developing sleeve 132. For this reason, when the rotating magnetic field becomes strong, the movement of the wire member 65 becomes active, and the kinetic energy when the wire member 65 collides with the outer surface of the developing sleeve 132 increases. The surface roughness becomes rough.

  Thereby, the surface roughness of the outer surface at an arbitrary position in the longitudinal direction (axial direction) of the developing sleeve 132 can be arbitrarily changed. Therefore, when the developing sleeve 132 is used as the developing sleeve 132, the pumping amount at an arbitrary position of the developing sleeve 132 can be increased and the pumping amount at an arbitrary position can be reduced. Accordingly, it is possible to increase the surface roughness of the developing sleeve 132 where the pumping amount is small and increase the pumping amount of the developing sleeve 132, and the image formed by the image forming apparatus 101 including the developing sleeve 132 is uneven. It can be prevented from occurring. Therefore, the surface of the developing sleeve 132 can be roughened so that unevenness of the image can be prevented.

  Since the control device 76 changes the strength of the rotating magnetic field in accordance with a predetermined pattern, the roughening process can be performed on the outer surface of the developing sleeve 132 in a constant pattern.

  Since the rotating magnetic field used when the control device 76 processes both ends is made stronger than the rotating magnetic field used when processing the central portion, the surface roughness of both end portions where the pumping amount of the developing sleeve 132 is small is increased. It can be made rougher than the surface roughness. Therefore, the surface roughness of both ends of the developing sleeve 132 with a small amount of pumping can be increased to increase the amount of pumping at both ends, and the image formed by the image forming apparatus 101 having the developing sleeve 132 can be formed. Unevenness can be reliably prevented. Therefore, it is possible to reliably perform the roughening process on the outer surface of the developing sleeve 132 so that unevenness of the image can be prevented.

  As the electromagnetic coil 8 moves, the developing sleeve 132 is processed, and at the same time, the wire 65 is suddenly removed from 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 developing sleeve 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 is possible to easily demagnetize the wire material 65, and the developing sleeve 132 can be continuously processed for a long time, so that the processing efficiency of the surface treatment can be improved. Therefore, it is possible to obtain the surface treatment apparatus 1 as a mass production apparatus on the premise of mass production of the developing sleeve 132.

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

  When the wire rod 65 moves (revolves) on the outer periphery of the developing sleeve 132, the wire rod 65 can be reliably collided with the outer surface of the object to be processed, and the developing sleeve 132 is reliably processed. be able to.

  Since the developing sleeve 132 is rotated, the linear member 65 can be uniformly collided with the outer surface of the developing sleeve 132, and the outer surface of the developing sleeve 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. Therefore, it is possible to improve the processing efficiency of the developing sleeve 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 more uniformly with the outer surface of the developing sleeve 132. 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, the roughening range of the outer surface of the developing sleeve 132 can be divided. 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 developing sleeve 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 developing sleeve 132 as a mass production apparatus on the premise of mass production.

  In the developing device 113 described above, a magnet block 141a for forming the developing region 131 on the outer surface of the developing sleeve 132 and a magnet block 141b adjacent to the magnet block 141a are provided. However, in the present invention, a magnetic pole corresponding to the magnet block 141b may be formed on the roller body 140 without providing the magnet block 141b described above. In short, in the present invention, it is desirable that the magnet block 141a for forming the developing region 131 on at least the outer surface of the developing sleeve 132 is made of a material containing a rare earth element.

  In the image forming apparatus 101 described above, the process cartridges 106Y, 106M, 106C, and 106K include a cartridge case 111, a charging roller 109, a photosensitive drum 108, a cleaning blade 112, and a developing device 113. However, in the present invention, the process cartridges 106Y, 106M, 106C, and 106K need only include at least the developing device 113, and do not necessarily include the cartridge case 111, the charging roller 109, the photosensitive drum 108, and the cleaning blade 112. . In the above-described embodiment, the image forming apparatus 101 includes the process cartridges 106Y, 106M, 106C, and 106K that are detachable from the apparatus main body 102. However, in the present invention, the image forming apparatus 101 only needs to include the developing device 113 and does not necessarily include the process cartridges 106Y, 106M, 106C, and 106K.

  In the above-described embodiment, it is needless to say that the outer diameter of the developing sleeve 132, the size of the linear member 65, and the outer diameter of the cylindrical member 50 of the storage tank 9 may be appropriately changed. In addition, regarding the shape of both ends of the developing sleeve 132, the target surface roughness, processing time (processing conditions), the number of reciprocations of the electromagnetic coil 8, and the filaments are also set such as the radius of curvature of chamfering and the size of the chamfering shape. It is desirable to select an appropriate shape from the durability of the material 65 and the like. Moreover, the total amount of the wire rod 65 accommodated in the storage tank 9 is also appropriate from the target roughness of the rough surface, the processing time (processing conditions), the number of reciprocations of the electromagnetic coil 8, the durability of the wire rod 65, and the like. It is desirable that the amount be determined in a proper amount.

  Furthermore, the inventor of the present invention has a developing sleeve 132 having an outer diameter of 25 mm, a material of A6063 and a different roughening method of the outer surface, and a pipe shape having an outer diameter of 23 mm, an inner diameter of 6 mm, and a length of 314 mm. A plurality of types of developing rollers 115 including the roller main body 140 formed in the above-described manner were manufactured, and evaluation was performed when an image after 100K sheets was formed using the developing roller 115. The results are shown in Table 1.

  The magnet roller 133 was manufactured for the following. Extruded while applying a magnetic field with 100 parts by weight of Sr ferrite as magnetic powder, 7.7 parts by weight of EFA (35% by weight of EA) as binder, and 0.5 parts by weight of low molecular weight polypropylene as resin lubricant. A pipe-shaped roller body 140 was molded. Then, after demagnetizing, the core shaft 134 having an outer diameter of 6 mm is press-fitted into the roller body 140, and the grooves 142a and 142b described above are formed by milling, and then the magnetized magnet blocks 141a and 141b are grooved. It was embedded in 142a and 142b. Thereafter, each magnetic pole was formed by yoke magnetization and adjusted to desired magnetic characteristics.

  Moreover, the magnet block of the present invention was manufactured as follows. 950 g of Magfine MFP-13 (anisotropic Ne-Fe-B rare earth magnet) manufactured by Aichi Steel Co., Ltd. was weighed, and quaternary ammonium salt (charge control agent) 1.5 wt. 50 g of a thermoplastic resin in which 1.5 parts by weight of styrene acrylic resin (low softening point substance), 2.0 parts by weight of carbon black are internally added, and 1.5 parts by weight of silica (H2000) is externally added And kneaded with a tumbler mixer under conditions of 22 rpm × 10 min.

  8.0 g of the above material is filled in a cavity (width 2.5 mm, depth 14.0 mm, length 312 mm) of a mold made of a magnetic material (SKS3) (magnet compact size is 2.0 mm × 2 .5 mm × 312 mm) and 20.1 g filling (molded product dimensions are 5.0 mm × 2.5 mm × 312 mm), and while flowing 100 A as an orientation current in a direction perpendicular to the press direction, Molding was performed by applying a press pressure of 400 kN. Thereafter, the mold and the magnet block were demagnetized with a pulse voltage of 3500 V, the mold was opened, the magnet block was removed, and these magnet blocks were fired at 100 ° C. for 60 minutes.

(Comparative Example 1)
In Comparative Example 1, a V-groove was formed on the outer surface of the developing sleeve 132, and conventionally used plastic magnets were used as the magnet blocks 141a and 141b. The attenuation rate of the plastic magnet is 32%, the half width is 45 degrees, and the maximum magnetic flux density is 110 mT.

(Comparative Example 2)
In Comparative Example 2, a V groove was formed on the outer surface of the developing sleeve 132, the above-described magnet block of the present invention was used as the magnet block 141a, and a conventionally used plastic magnet was used as the magnet block 141b.

(Comparative Example 3)
In Comparative Example 3, the outer surface of the developing sleeve 132 was sandblasted, and conventionally used plastic magnets were used as the magnet blocks 141a and 141b.

(Comparative Example 4)
In Comparative Example 3, the outer surface of the developing sleeve 132 was sandblasted, the magnet block of the present invention described above was used as the magnet block 141a, and a conventionally used plastic magnet was used as the magnet block 141b.

(Invention product 1)
In the product 1 of the present invention, the outer surface of the developing sleeve 132 is subjected to a roughening process using the surface treatment apparatus 1, and the magnet block of the present invention described above is used as the magnet block 141a, and the magnet block 141b has been conventionally used. A plastic magnet is used.

(Invention product 2)
In the product 2 of the present invention, the outer surface of the developing sleeve 132 is subjected to a surface roughening process using the surface treatment apparatus 1, and conventionally used plastic magnets are used as the magnet blocks 141 a and 141 b.

(Invention product 3)
In the product 3 of the present invention, the outer surface of the developing sleeve 132 is subjected to a surface roughening process using the surface treatment apparatus 1, and the above-described magnet blocks of the present invention are used as the magnet blocks 141a and 141b.

  The evaluation criteria in Table 1 are ◎ for those that are very good, ○ for those that can withstand practical use, and △ for those that are inferior to practical use.

  According to Table 1, it was found that Comparative Examples 1 to 4 were inferior in at least one of developing ability, trailing edge blank, and horizontal fine line reproducibility. Further, it was revealed that Comparative Examples 1 to 4 were inferior due to magnetic carrier adhesion.

  On the other hand, according to Table 1, the products 1 to 3 of the present invention were found to be excellent in any of developing ability, trailing edge blank, horizontal fine line reproducibility, and magnetic carrier adhesion. Furthermore, it was revealed that the product 3 of the present invention is very excellent in all.

  As described above, it has been clarified that the products 1 to 3 of the present invention are extremely excellent and can withstand practical use with almost no decrease in the pumping amount of the developer. Further, it has been clarified that the products 1 to 3 of the present invention do not cause unevenness in the test image and are extremely excellent in terms of unevenness and can withstand practical use.

  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. That is, the holding unit, the rotating unit, and the magnetic field changing unit are not limited to the configurations and arrangements described in the embodiments, and may be various configurations and arrangements.

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. 2 is a perspective view showing a developing sleeve of the image forming apparatus shown in FIG. 1. FIG. 3 is a sectional view of a magnet roller of the image forming apparatus shown in FIG. 2. FIG. 6 is an exploded perspective view of the magnet roller shown in FIG. 5. FIG. 5 is an explanatory diagram showing an enlarged outer surface of the developing sleeve shown in FIG. 4. It is explanatory drawing which shows typically the outer surface of the image development sleeve shown by FIG. FIG. 3 is a cross-sectional view of a magnetic carrier of a developer in the developing device shown in FIG. 2. FIG. 5 is a perspective view showing a schematic configuration of a surface treatment apparatus that performs a roughening process on the outer surface of the developing sleeve shown in FIG. 4. It is sectional drawing which follows the II-II line | wire in FIG. It is a perspective view of the filament material used with the surface treatment apparatus shown by FIG. It is sectional drawing which follows the XI-XI line in FIG. It is explanatory drawing which shows the filament material which revolves around the developing sleeve of the surface treatment apparatus shown by FIG. 10, and rotates the outer periphery of a developing sleeve. FIG. 15 is an explanatory diagram illustrating a state in which the linear material illustrated in FIG. 14 collides with the outer surface of the developing sleeve. It is explanatory drawing of the magnetic powder which comprises the magnet roller shown by FIG. It is explanatory drawing of the magnet compound for compression molding which comprises the magnet roller shown by FIG. FIG. 7 is an enlarged explanatory view of a compression molding magnet compound constituting the magnet roller shown in FIG. 6.

Explanation of symbols

8 Electromagnetic coil (magnetic field generator)
DESCRIPTION OF SYMBOLS 9 Storage tank 65 Line material 101 Image forming apparatus 106Y, 106M, 106C, 106K Process cartridge 108 Photosensitive drum (electrostatic latent image carrier)
113 Developing Device 115 Developing Roller (Developer Carrier)
131 Development region 132 Development sleeve 133 Magnet roller 139 Recess 140 Roller body (cylindrical magnet molded body)
141 Magnet block (long magnet molded body)
142, 142a groove 142b groove (second groove)
150A, 150B Compression molding magnet compound 151 Magnetic powder 152 Magnetic particle 153 Thermoplastic resin fine particle R Rotating direction of developing sleeve

Claims (14)

Development in which a magnet roller and a developing area that encloses the magnet roller and attracts the developer to the outer surface by the magnetic force of the magnet roller and delivers the toner of the developer to the electrostatic latent image carrier are formed on the outer surface. In a developer carrier comprising a sleeve,
(A) The attenuation rate of the magnetic flux density in the normal direction of the development region is 40% or more ,
(B) A large number of elliptical dents are randomly provided on the outer surface of the developing sleeve ;
(C) the plurality of elliptical depressions are formed by a linear member positioned in the rotating magnetic field and rotated by the rotating magnetic field and randomly collided with the outer surface of the developing sleeve; and
(D) The plurality of elliptical recesses include a recess whose longitudinal direction is along the axial direction of the developing sleeve, and a recess whose longitudinal direction is along the circumferential direction of the developing sleeve, and the longitudinal direction is the developing sleeve. The developer carrying member according to claim 1, wherein the number of the dents along the axial direction is greater in the longitudinal direction than the dent along the circumferential direction of the developing sleeve . 2. The developer carrying member according to claim 1, wherein outer edges of both ends of the wire rod are chamfered in a circular arc shape over the entire circumference. The major axis of the dent is 0.05 mm or more and 0.3 mm or less, and the minor axis of the dent is 0.02 mm or more and 0.1 mm or less. Item 3. The developer carrying member according to Item 2. The magnet roller has a cylindrical magnet molded body in which at least one concave groove is provided so that another member can be embedded in a portion corresponding to the development area, and the cylindrical magnet molding is embedded in the groove. The developer carrying member according to any one of claims 1 to 3, further comprising a long magnet molded body that has a higher magnetic force than the body and includes a rare earth element. A concave second groove is further provided on the downstream side of the concave groove of the cylindrical magnet molded body in the rotation direction of the developing sleeve and in which another member can be embedded; and
5. The developer carrying member according to claim 4, further comprising a long magnet molded body embedded in the second groove and having a higher magnetic force than the cylindrical magnet molded body and containing a rare earth element. body. The long magnet molded body is a long magnet molded body formed by compression molding a compression molding magnet compound having a magnetic powder containing rare earth elements and thermoplastic resin fine particles in a magnetic field. The developer carrying member according to claim 4 or 5 . The magnetic powder, the developer carrying member according to claim 6, wherein the bulk density of which is adjusted to ^{3.3g / cm 3 ~4.0g / cm 3} . The developer carrying member according to claim 6 or 7 , wherein an average particle diameter of the thermoplastic resin fine particles is 1/10 or less of an average particle diameter of the magnetic particles of the magnetic powder. The developer carrying member according to any one of claims 6 to 8 , wherein the thermoplastic resin fine particles are spherical fine particles produced by an emulsion polymerization method or a suspension polymerization method. 10. The developing sleeve according to claim 1, wherein the developing sleeve is housed in a housing tank together with the filament material, and a magnetic field generation unit generates the rotating magnetic field in the housing tank. The developer carrying member according to Item . The developer carrying member according to claim 10, wherein the linear member is collided while the developing sleeve accommodated in the accommodating tank is rotated about its axis. In a developing device comprising a developer carrier having a developing sleeve that adsorbs the developer on the outer surface,
Wherein as the developer carrying member, a developing apparatus comprising the developer carrying member according to any one of claims 1 to 11. A process cartridge having at least a developing device, wherein the developing device includes the developing device according to claim 12 . In at least comprising an image forming apparatus and the process cartridge having a developing device, at least, as the process cartridge, an image forming apparatus comprising the process cartridge according to claim 13, wherein.