Patent Grant
9248638
This patent application is based on and claims priority pursuant to 35 U.S.C. §119(a) to Japanese Patent Application Nos. 2014-010086, filed on Jan. 23, 2014 and 2014-133543, filed on Jun. 30, 2014 in the Japan Patent Office, the entire disclosure of each of which is hereby incorporated by reference herein.
1. Technical Field
Embodiments of this disclosure relate to a cleaning device including multiple cleaning members to scrape off adhered substance on a surface of a cleaning target and an image forming apparatus employing the cleaning device to remove toner on a surface of an image bearer.
2. Description of the Related Art
Image forming apparatuses are used as, for example, copiers, printers, facsimile machines, and multi-functional devices having at least one of the foregoing capabilities. Such an image forming apparatus may include an image bearer to bear a toner image on a surface thereof and a cleaning device to remove adhered substance, e.g., toner particles from the surface of the image bearer.
For example, as illustrated in
The sub-unit holder 950 has a first support 951 to support the first sub unit 901 in such a manner that the first sub unit 901 is slidable in a longitudinal direction thereof (a direction perpendicular to a sheet surface on which
For such a configuration, when one of the cleaning brush roller 902, the cleaning brush roller 912, and the cleaning brush roller 922 comes to the end of product life, a user can replace only one of the multiple sub cleaning units including the cleaning brush roller having come to the end of product life with a new one and continue to use the other sub cleaning units remaining in the cleaning device 900. Such a configuration can reduce servicing cost of the cleaning device as compared with a configuration in which a single holder holds multiples components.
In at least one aspect of this disclosure, there is provided an improved cleaning device including a cleaner, a plurality of cleaning sub-units, a sub-unit holder, a detachable transmission assembly, and a plurality of joint couplers. The cleaner scrapes off adhered material from a surface of a cleaning target while contacting the surface of the cleaning target. The plurality of cleaning sub-units each includes a holder to hold the cleaner and a drive-receive rotator to receive a driving force. The sub-unit holder holds the plurality of cleaning sub-units. The detachable transmission assembly includes a driving-force receive rotator to receive a driving force from an external unit and a plurality of drive transmission rotators to transmit the driving force received by the driving-force receive rotator to the drive-receive rotators of the plurality of cleaning sub-units. The plurality of joint couplers mounted on the drive-receive rotators and the plurality of drive transmission rotators couple the drive-receive rotators with the plurality of drive transmission rotators in a rotation axial direction.
In at least one aspect of this disclosure, there is provided an improved image forming apparatus including an image bearer, an image forming device, and a cleaning device. The cleaning device includes a cleaner, a plurality of cleaning sub-units, a sub-unit holder, a detachable transmission assembly, and a plurality of joint couplers. The cleaner scrapes off toner as adhered substance from the surface of the image bearer. The plurality of cleaning sub-units each includes a holder to hold the cleaner and a drive-receive rotator to receive a driving force. The sub-unit holder holds the plurality of cleaning sub-units. The detachable transmission assembly includes a driving-force receive rotator to receive a driving force from an external unit and a plurality of drive transmission rotators to transmit the driving force received by the driving-force receive rotator to the drive-receive rotators of the plurality of cleaning sub-units. The plurality of joint couplers mounted on the drive-receive rotators and the plurality of drive transmission rotators couples the drive-receive rotators with the plurality of drive transmission rotators in a rotation axial direction.
In at least one aspect of this disclosure, there is provided an improved unit device detachably attachable relative to a machine body. The device includes a plurality of sub units, a sub-unit holder, a plurality of cleaning sub-units, a sub-unit holder, a detachable transmission assembly, and a plurality of joint couplers. The plurality of sub units each includes a driver to be driven by a driving force. The sub-unit holder holds the plurality of sub-units. The plurality of cleaning sub-units each includes a holder to hold the cleaner and a drive-receive rotator to receive a driving force. The sub-unit holder holds the plurality of cleaning sub-units. The detachable transmission assembly includes a driving-force receive rotator to receive a driving force from an external unit and a plurality of drive transmission rotators to transmit the driving force received by the driving-force receive rotator to the drive-receive rotators of the plurality of cleaning sub-units. The plurality of joint couplers mounted on the drive-receive rotators and the plurality of drive transmission rotators couple the drive-receive rotators with the plurality of drive transmission rotators in a rotation axial direction.
The aforementioned and other aspects, features, and advantages of the present disclosure would be better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted.
In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this patent specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner and achieve similar results.
Although the embodiments are described with technical limitations with reference to the attached drawings, such description is not intended to limit the scope of the disclosure and all of the components or elements described in the embodiments of this disclosure are not necessarily indispensable.
Referring now to the drawings, embodiments of the present disclosure are described below. In the drawings for explaining the following embodiments, the same reference codes are allocated to elements (members or components) having the same function or shape and redundant descriptions thereof are omitted below.
As an image forming apparatus according to an embodiment of this disclosure, a tandem-type printer of an intermediate transfer system (to be simply referred to as a printer hereinafter) is described below. However, the image forming apparatus is not limited to the tandem-type printer of an intermediate transfer system and may be any other suitable type of image forming apparatus. First, a basic configuration of the image forming apparatus according to this embodiment is described below.
Below the process units 6Y, 6M, 6C, and 6K is disposed a transfer unit 7 including an endless intermediate transfer belt 8 serving as an image bearer. In addition to the intermediate transfer belt 8, the transfer unit 7 includes, e.g., a plurality of extension rollers disposed inside a loop of the intermediate transfer belt 8, a secondary transfer roller 18 disposed outside the loop, a tension roller 16, a belt cleaning device 100, and a lubricant application device 200.
Inside the loop of the intermediate transfer belt 8, four primary transfer rollers 9Y, 9M, 9C, and 9K, a driven roller 10, a driving roller 11, a secondary-transfer opposed roller 12, three cleaning opposed rollers 13, 14, and 15, and an applying brush opposed roller 17 are disposed. Each of all the rollers functions as an extension roller having a peripheral surface on which the intermediate transfer belt 8 is partially hung to extend the belt. As a necessary condition of the cleaning opposed rollers 13, 14, and 15, the cleaning opposed rollers 13, 14, and 15 need not necessarily give a predetermined tension to the belt. The cleaning opposed rollers 13, 14, and 15 may be driven and rotated with the rotation of the intermediate transfer belt 8. The intermediate transfer belt 8 is endlessly moved in the counterclockwise direction in
The four primary transfer rollers 9Y, 9M, 9C, and 9K disposed inside the belt loop sandwich the intermediate transfer belt 8 between the primary transfer rollers 9Y, 9M, 9C, and 9K and the photoconductors 1Y, 1M, 1C, and 1K, respectively. In this manner, primary transfer nips for Y, M, C, and K on which the front surface of the intermediate transfer belt 8 is brought into contact with the photoconductors 1Y, 1M, 1C, and 1K are formed. Primary transfer biases each having a polarity opposite that of toner are applied to the primary transfer rollers 9Y, 9M, 9C, and 9K with power supplies, respectively.
The secondary-transfer opposed roller 12 disposed inside the belt loop sandwiches the intermediate transfer belt 8 between the secondary-transfer opposed roller 12 and a secondary transfer roller 18 disposed outside the belt loop. In this manner, a secondary transfer nip on which the front surface of the intermediate transfer belt 8 is brought into contact with the secondary transfer roller 18 is formed. A secondary transfer bias having a polarity opposite that of toner is applied to the secondary transfer roller 18 with a power supply. A sheet conveyance belt may be bridged by a secondary transfer roller, several support rollers, and a driving roller, and the intermediate transfer belt 8 and the sheet conveyance belt may be sandwiched between the secondary transfer roller 18 and the secondary-transfer opposed roller 12.
The three cleaning opposed rollers 13, 14, and 15 disposed inside the belt loop sandwich the intermediate transfer belt 8 between the cleaning opposed rollers 13, 14, and 15 and three cleaning brush rollers of a belt cleaning device 100 disposed outside the belt loop. In this manner, a cleaning nip on which the front surface of the intermediate transfer belt 8 is brought into contact with the three cleaning brush rollers is formed. The belt cleaning device 100 is replaceable together with the transfer unit 7. The belt cleaning device 100 is also removable from the transfer unit 7 having removed from an apparatus body of the image forming apparatus. Furthermore, with the transfer unit 7 and the belt cleaning device 100 mounted in the apparatus body, a sub cleaning unit is removably mountable relative to the belt cleaning device 100. The belt cleaning device 100 will be described in detail below.
The image forming apparatus according to this embodiment includes a sheet feed section having a sheet feed tray to store a recording sheet P, a sheet feed roller that feeds the recording sheet P from the sheet feed tray to a sheet feed path. A pair of registration rollers to receive the recording sheet P sent from the sheet feed section and sends the recording sheet P toward the secondary transfer nip at a proper timing is disposed on the right side of the secondary transfer nip in
In recent years, the frequency of use of, in addition to a plain sheet that has been conventionally and widely used as a recording sheet, a special sheet designed to have uneven surfaces or a special recording sheet used for thermal transfer such as ironing print has been increased. When the special sheet is used, in comparison with in use of a conventional regular sheet, defective transfer is likely to occur when a toner image on the intermediate transfer belt 8 obtained by overlapping color toner images is secondarily transferred onto a sheet. Hence, in the image forming apparatus, an elastic layer having low hardness is formed on the intermediate transfer belt 8, so that the intermediate transfer belt 8 can be transformed for the toner layer or a recording sheet having poor smoothness at the transfer nipping portion. The elastic layer having low hardness is formed on the intermediate transfer belt 8 to make the intermediate transfer belt 8 elastic, so that the surface of the intermediate transfer belt 8 can be transformed in accordance with local irregularity. In this manner, good tightness can be achieved without excessively increasing a transfer pressure on the toner layer, character missing in transfer does not occur, and a uniform transferred image in which uneven transfer does not occur on a sheet or the like having poor smoothness can be obtained.
In the image forming apparatus, the intermediate transfer belt 8 includes at least a base layer, an elastic layer, and a coat layer serving as the uppermost layer.
As a material used in the elastic layer of the intermediate transfer belt 8, an elastic member such as an elastic material rubber or an elastomer is given. More specifically, one or more selected from the group consisting of isobutylene-isoprene rubber, fluororubber, acrylic rubber, ethylene propylene diene monomer (EPDM), nitrile rubber (NBR), acrylonitrile-butadiene-styrene rubber, natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, polyurethane rubber, syndiotactic 1,2-polybutadiene, epichlorohydrin rubber, polysulfide rubber, polynorbornene rubber, and thermoplastic elastomer (for example, polystyrene resin, polyolefin resin, polyvinyl chloride resin, polyurethane resin, polyamide resin, polyurea resin, polyester resin, and fluorine resin) can be used. However, the material used in the elastic layer is not limited to the above materials.
The thickness of the elastic layer, depending on a hardness and a layer configuration, preferably ranges from 0.07 mm to 0.5 mm. More preferably, the thickness ranges from 0.25 mm to 0.5 mm. When the thickness of the intermediate transfer belt 8 is small, i.e., 0.07 mm or less, a pressure on toner on the intermediate transfer belt 8 at the secondary transfer nip becomes high, character missing in transfer is likely to occur, and a transfer ratio of toner decreases.
The hardness of the elastic layer preferably falls within a range given by 10°≦HS≦65° (JIS-A). Although an optimum hardness changes depending on the layer thickness of the intermediate transfer belt 8, when the hardness is lower than 10° (JIS-A), character missing in transfer is likely to occur. By contrast, when the hardness is higher than 65° (JIS-A), the intermediate transfer belt 8 is difficult to stretch between the rollers, and the intermediate transfer belt 8 extends due to long-term stretching to lose the durability. As a result, the intermediate transfer belt 8 need to be early exchanged.
The base layer of the intermediate transfer belt 8 is made of a resin having low elongation. More specifically, as a material used in a base layer, one or more selected from a group consisting of styrene resin (single polymer including styrene or a styrene substitute or copolymer) such as polycarbonate, fluoro resin (ethylene tetrafluoroethylene (ETFE), polyvinylidene difluoride (PVDF), or the like), polystyrene, chloropolystyrene, poly-α-methyl styrene, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic ester copolymer (styrene-acrylic acid methyl copolymer, styrene-acrylic acid ethyl copolymer, styrene-acrylic acid butyl copolymer, styrene-acrylic acid octyl copolymer, styrene-acrylic acid phenyl copolymer, or the like), styrene-methacrylic acid ester copolymer (styrene-methyl methacrylate copolymer, styrene-methacrylic acid ethyl copolymer, styrene-methacrylic acid phenyl copolymer, or the like), styrene-α-chloracrylic acid methyl copolymer, styrene-acrylonitrile-acrylic ester copolymer, methyl methacrylate resin, methacrylate butyl resin, acrylic acid ethyl resin, acrylic acid butyl resin, denaturing acrylic acid resin (silicone denaturation acrylic acid resin, vinyl chloride resin denaturation acrylic acid resin, acrylic urethane resin, or the like), vinyl chloride resin, styrene-vinyl acetate copolymer, vinyl chloride-vinyl acetate copolymer, rosin-modified maleic acid resin, phenolic resin, epoxy resin, polyester resin, polyester polyurethane resin, polyethylene, polypropylene, polybutadiene, polyvinylidene chloride, an ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin and polyvinyl butyral resin, polyamide resin, modified polyphenylene oxide resin, and the like can be used. However, the material used in the elastic layer is not limited to the above materials.
In order to prevent elongation of the elastic layer made of a rubber material or the like having high elongation, a core layer made of a material such as canvas or the like may be disposed between the base layer and the elastic layer. As a material that is used in the core layer to prevent elongation of the core layer, for example, one or more selected from the group consisting of a natural fiber such cotton or silk, a synthetic fiber such as a polyester fiber, a nylon fiber, an acrylic fiber, a polyolefin fiber, a polyvinyl alcohol fiber, a polychlorinated vinyl fiber, a polyvinylidene chloride fiber, a polyurethane fiber, a polyacetal fiber, a polyphloroethylene fiber, or a phenol fiber, an inorganic fiber such as a carbon fiber or a glass fiber, and a metal fiber such as an iron fiber or a copper fiber are used, and a fiber in the form of a thread or a woven cloth can be used. However, the material to prevent the elongation is not limited to the above materials. The thread may be one filament or obtained by twisting a plurality of filaments. A thread such as a single twist yarn, a plied yarn, or a two folded yarn that is twisted by any twisting method may be used. Fibers of materials selected from the material group described above may be blended. As a matter of course, a thread applied with an appropriate process to have electrical conductivity may be used. On the other hand, as a woven fabric, a woven fabric such as a knitted fabric that is woven by any weave can be used. A woven fabric obtained by combined weaving can also be used, and can also be applied with a process to have electrical conductivity.
The coat layer on the surface of the intermediate transfer belt 8 coats the surface of the elastic layer, and is constituted of a smooth layer. A material used in the coat layer is not limited to a specific one. However, in general, a material that reduces adherence of toner to the surface of the intermediate transfer belt 8 to improve secondary transfer properties is used. For example, particles made of one or more of polyurethane, polyester, an epoxy resin, and the like or one or more of materials that reduce surface energy to improve lubricity, for example, a fluorocarbon resin, a fluorine compound, fluorocarbon, a titanium oxide, and a silicon carbide can be used such that the particles are dispersed while being reduced in diameter as needed. A material such as a fluorine rubber material that is applied with thermal treatment to form a fluorine layer on the surface and to decrease surface energy can also be used.
As needed, as a base layer, an elastic layer, or a coat layer, in order to adjust the resistance, for example, metal powder of carbon black, graphite, aluminum, or nickel or a conductive metal oxide such as tin oxide, titanium oxide, antimony oxide, indium oxide, potassium titanate, antimony oxide-tin oxide complex oxide (ATO), indium oxide-tin oxide complex oxide (ITO), or the like can be used. In this case, the conductive metal oxide may be obtained by covering insulating fine particles of barium sulfate, magnesium silicate, calcium carbonate, or the like with a conductive metal oxide. However, the material used in the elastic layer is not limited to the above materials.
A lubricant is applied to the surface of the intermediate transfer belt 8 by a lubricant application device 200 to protect the belt surface. The lubricant application device 200 includes a solid lubricant 202 such as zinc stearate agglomerate and an application brush roller 201 serving as an application member that is brought into contact with the solid lubricant to apply lubricant powder obtained by scraping the solid lubricant with rotation to the surface of the intermediate transfer belt 8. The image forming apparatus includes the lubricant application device 200. However, depending on toner to be applied and the material and the surface friction coefficient of the intermediate transfer belt 8, the lubricant application device 200 need not be always included, and lubricant need not be necessarily applied.
When image information is sent from a personal computer or the like, the printer rotationally drives the driving roller 11 to endlessly move the intermediate transfer belt 8. Extension rollers except for the driving roller 11 are rotated by following the belt. At the same time, the photoconductors 1Y, 1M, 1C, and 1K of the process units 6Y, 6M, 6C, and 6K are rotationally driven. While the surfaces of the photoconductors 1Y, 1M, 1C, and 1K are uniformly electrically charged with the charging devices 2Y, 2M, 2C, and 2K, electrostatic latent images are formed by irradiating the laser beam L on the electrically charged surfaces. The electrostatic latent images formed on the surfaces of the photoconductors 1Y, 1M, 1C, and 1K are developed with the development devices 5Y, 5M, 5C, and 5K to obtain Y, M, C, and K toner images on the photoconductors 1Y, 1M, 1C, and 1K. The Y, M, C, and K toner images are superposed and primarily transferred on the front surface of the intermediate transfer belt 8 at the primary transfer nips for the Y, M, C and K. In this manner, a toner image in four colors is formed on the front surface of the intermediate transfer belt 8.
On the other hand, at the sheet feed section, recording sheets P are sent one by one from the sheet feed tray with a sheet feed roller 27 and transported to the pair of registration rollers. The pair of registration rollers are driven at a timing that can be synchronized with the toner image in four colors on the intermediate transfer belt 8 to send the recording sheet P to the secondary transfer nip, and the toner image in four colors on the belt is secondarily transferred on the recording sheet P in a lump. In this manner, a full-color image is formed on the surface of the recording sheet P. The recording sheet P after the full-color image is formed is transported from the secondary transfer nip to the fixing device to apply a fixing process for the toner image.
With respect to the photoconductors 1Y, 1M, 1C, and 1K after the Y, M, C, and K toner images are primarily transferred onto the intermediate transfer belt 8, a cleaning process for residual toner after transfer is performed by the drum cleaning devices 4Y, 4M, 4C, and 4K. Thereafter, after neutralization is performed with a neutralization lamp, the belt is uniformly electrically charged with the charging devices 2Y, 2M, 2C, and 2K to prepare the next image formation. The intermediate transfer belt 8 after the image is primarily transferred onto the recording sheet P, a cleaning process of residual toner after transfer is performed by the belt cleaning device 100.
On the right of the process unit 6K for K in
In the printer, in a power-on state or each time a predetermined number of prints are completed, image density control is executed to optimize the image densities of the colors. The image density control, as illustrated in
The toner patterns (Sk, Sm, Sc, and Sy) formed on the intermediate transfer belt 8 pass through positions facing the optical sensors 91 with the endless movement of the intermediate transfer belt 8. At this time, the optical sensors 91 receive amounts of light depending on amounts of adhesion of toner per unit area to the toner patches of the gradation patterns, respectively.
On the basis of output voltages from the optical sensors 91 when the toner patches are detected and an adhesion amount conversion algorithm, amounts of adhesion on the toner patches of the toner patterns in colors are calculated. On the basis of the calculated amounts of adhesion, image forming conditions are adjusted. More specifically, on the basis of the results of detection of the amounts of adhesion of toner on the toner patches and development potentials obtained when the toner patches are formed, a function (y=ax+b) representing the linear graph is calculated by regression analysis. Target values of the image densities are assigned to the function to calculate appropriate development biases, so that development biases for Y, M, C, and K are specified.
In the memory, an image formation condition data table is stored in which several tens of kinds of development biases and appropriate drum charging potentials respectively corresponding to the biases are associated with each other. With respect to the process units 6Y, 6M, 6C, and 6K, development biases that are closest to the specified development biases are selected from the image formation condition table to specify drum charging potentials associated with the selected development biases.
The printer is configured to also perform color shift correction processing when the printer is powered on or when a predetermined number of prints are completed. In the color shift correction processing, color shift detection images called chevron patches PV as shown in
The color toner images in the chevron patches PV formed at both the ends of the intermediate transfer belt 8 in the width direction are detected. In this manner, positions in the main scanning direction D1 (axial direction of the photoconductor) in the color toner images, positions in the sub-scanning direction (belt moving direction) D2, magnification errors in the main scanning direction D1, and skew from the main scanning direction D1 are detected. The main scanning direction D1 mentioned here is a direction in which a laser beam is phase-shifted on the surface of the photoconductor with reflection on a polygon mirror.
Detection time differences between the Y, M, and C toner images in the chevron patch PV and the K toner image are read by the optical sensors 91. In
On the basis of differences between measured values and ideal values of detection time differences tky, tkm, and tkc obtained with reference to the K color serving as a reference color, deviations of the color toner images in the sub-scanning direction D2, i.e., registration deviations, are calculated. On the amount of registration deviations, every other surface of the polygon mirror in the optical writing unit constituting part of a toner image forming unit, i.e., using one scanning line pitch as one unit, an optical writing start timing for a photoconductor 1 is corrected to reduce the registration deviations of the color toner images.
On the basis of the differences of deviations in sub-scanning direction D2 between both the ends of the belt, tilts (skews) of the color toner images from the main scanning direction D1 are calculated. On the basis of the result, plate tilt correction of an optical reflecting mirror is performed to reduce skew deviations of the color toner images. Processing that corrects an optical writing start timing and a plate tilt on the basis of timings at which the toner images in the chevron patch PV are detected to reduce registration deviations and skew deviations is color shift correction processing. The color shift correction processing can suppress color shift of an image caused by shifting forming positions of the color toner images on the intermediate transfer belt 8 with time due to a change in temperature or the like.
When the image forming operation in a small image area continues, old toner continuously remaining in the development device for a long time increases. For this reason, the toner charging characteristics are deteriorated, and use of the toner in image formation deteriorates image quality (deterioration in development capability and transfer properties). The image forming device includes a refresh mode in which old toner is ejected into a non-image region of the photoconductor 1 at a predetermined timing not to be accumulated in the development device, and, after the toner is ejected, a new toner is supplied to the development device having a decreased toner concentration to refresh the interior of the development device.
A controller stores consumptions of toner of the development devices 5Y, 5M, 5C, and 5K and operation times of the development devices 5Y, 5M, 5C, and 5K therein in advance. At a predetermined timing, the controller examines whether a consumption of toner for an operation time in a predetermined period of each development device is a threshold value or less in each of the developments, and executes the refresh mode to a development device having a consumption of toner that is the threshold value or less.
When the refresh mode is executed, a toner consumption pattern A is formed in a non-image-forming region corresponding to a region between sheets of the photoconductor 1 and transferred to the intermediate transfer belt 8 (
The color gradation patterns, the chevron patches, and the toner consumption pattern formed on the intermediate transfer belt 8 are collected by the belt cleaning device 100. At this time, the belt cleaning device 100 removes a large amount of toner from the intermediate transfer belt 8. However, a conventional type of cleaning device including a polarity controller and a brush roller or a conventional type of cleaning device including a brush roller for removing toner having a positive polarity and a brush roller for removing toner having a negative polarity may not remove a large amount of toner from the intermediate transfer belt 8. More specifically, such a conventional type of cleaning device may not remove the non-transferred toner images such as the color gradation patterns, the chevron patches, and the toner consumption pattern in a lump. In such a case, the toner on the intermediate transfer belt 8 that cannot be completely cleaned is transferred onto a recording sheet in the next print operation, and an abnormal image may be formed.
Thus, the belt cleaning device 100 of the printer is configured such that non-transferred toner images such as the color gradation patterns, the chevron patches, and the toner consumption pattern can be removed in a lump.
The first sub cleaning unit 101 includes a first cleaning brush roller 102 serving as a cleaner to scrape off post-transfer residual toner from the surface of the intermediate transfer belt 8. The first sub cleaning unit 101 also includes a first collection roller 103 to collect post-transfer residual toner from the first cleaning brush roller 102 by rotating in contact with the first cleaning brush roller 102 and a first scraping blade 104 to scrape post-transfer residual toner from a surface of the first collection roller 103. The first sub cleaning unit 101 further includes a first sub-unit casing 106 serving as a holder. The first sub-unit casing 106 includes a first transport screw 105 to discharge post-transfer residual toner scraped off from the first collection roller 103 to the outside of the first sub-unit casing 106.
Similarly with the first sub cleaning unit 101, the second sub cleaning unit 111 has the following configuration. For example, the second sub cleaning unit 111 includes a second cleaning brush roller 112 serving as a cleaning member, a second collection roller 113, a second scraping blade 114, a second transport screw 115, and a second sub-unit casing 116.
Similarly with the first cleaning sub-unit 101, the third cleaning sub-unit 121 has the following configuration. For example, the third cleaning sub-unit 112 includes a third cleaning brush roller 122 serving as a cleaning member, a third collection roller 123, a third scraping blade 124, a third transport screw 125, and a third sub-unit casing 126.
Each of the first cleaning sub-unit 101, the second cleaning sub-unit 111, and the third cleaning sub-unit 121 is removably mounted relative to a sub-unit holder casing 150 serving as a sub-unit holder of each belt cleaning device.
Most of toner particles constituting the post-transfer residual toner are charged to have a negative polarity that is a regular charging polarity. For the first cleaning sub-unit 101 at the most upstream side of the three cleaning sub-units, the first cleaning brush roller 102 is applied with a cleaning bias of a polarity (positive polarity) opposite the regular charging polarity of toner. Thus, post-transfer residual toner charged with the charging polarity (negative polarity) generated on the intermediate transfer belt 8 is electrostatically captured to a brush of the first cleaning brush roller 102. The first collection roller 103 is applied with a collection bias of positive polarity of a value greater than the cleaning bias. For the belt cleaning device 100, the cleaning bias is set so that about 90% of post-transfer residual toner generated on the surface of the intermediate transfer belt 8 is removed with the first cleaning brush roller 102.
The post-transfer residual toner may slightly include toner charged with the polarity opposite the regular charging polarity. Hence, the second cleaning brush roller 112 of the second cleaning sub-unit 111 is applied with a cleaning bias of the same polarity as the regular charging polarity (negative polarity) of toner. Thus, of the post-transfer residual toner, toner particles charged with the opposite polarity are electrostatically captured to a brush of the second cleaning brush roller 112. The second collection roller 113 is applied with a collection bias of negative polarity of a value greater than the cleaning bias. The second cleaning brush roller 112 acts as a polarity regulator to inject charges of negative polarity, which is the regular charging polarity of toner, to toner particles charged with the opposite polarity to return the toner particles charged with the opposite polarity to the regular polarity.
The third cleaning brush roller 122 of the third cleaning sub-unit 121 is applied with a cleaning bias of positive polarity opposite the regular charging polarity of toner. The third collection roller 123 is applied with a collection bias of positive polarity of a value greater than the cleaning bias.
The second sub-unit casing 116 of the second cleaning sub-unit 111 has a first insulation seal 171 at the vicinity of an opening for exposing the second cleaning brush roller 112 to the outside of the second sub-unit casing 116, to prevent falling of toner particles charged with the opposite polarity. The first insulation seal 171 prevents occurrence of electric discharge between the first cleaning brush roller 102 and the second cleaning brush roller 112. The first insulation seal 171 also prevents migration of toner particles charged with the opposite polarity from the second sub-unit casing 116 to the first sub-unit casing 106.
The third sub-unit casing 126 of the third cleaning sub-unit 121 has a second insulation seal 172 at the vicinity of an opening for exposing the third cleaning brush roller 122 to the outside of the third sub-unit casing 126, to prevent falling of post-transfer residual toner. The second insulation seal 172 prevents occurrence of electric discharge between the third cleaning brush roller 122 and the second cleaning brush roller 112. The second insulation seal 172 also prevents migration of post-transfer residual toner (charged with the regular polarity) from the third sub-unit casing 126 to the second sub-unit casing 116.
The third sub-unit casing 126 of the third cleaning sub-unit 121 has a third insulation seal 173 above an opening for exposing the third cleaning brush roller 122 to the outside of the third sub-unit casing 126. The third insulation seal 173 prevents occurrence of electric discharge between the third cleaning brush roller 122 and the tension roller 16 (illustrated in
The cleaning brush rollers 102, 112, and 122 include metal rotation shafts 102a, 112a, 122a and brushes 102b, 112b, 122b, respectively. Each of the metal rotation shafts 102a, 112a, 122a is rotationally supported. Each of the brushes 102b, 112b, 122b has a plurality of raising fibers standing on the peripheral surface of the rotation shaft and has an external diameter φ of 15 mm to 16 mm. Each of the raising fibers has a two-layered core-sheath structure in which the inside of each of the raising fibers is made of a conductive material such as conductive carbon, and the surface portion of each of the rising fibers is made of an insulating material such as polyester. In this manner, the cores have substantially the same potential as that of the cleaning bias applied to the cleaning brush rollers 102, 112, and 122, and toner can be electrostatically attracted to the surfaces of the raising fibers. As a result, toner particles on the intermediate transfer belt 8 are electrostatically captured to the raising fibers of the cleaning brush rollers 102, 112, and 122.
In some embodiments, the raising fibers of the cleaning brush rollers 102, 112, and 122 are formed of only conductive fibers, not the two-layered core-sheath structure. In some embodiments, fibers are planted to be slanted with respect to a normal direction of the rotation shaft 102a, 112a, 122a. In some embodiments, the raising fibers of the first cleaning brush roller 102 and the third cleaning brush roller 122 applied with a cleaning bias of positive polarity have core-sheath structures, and the raising fibers of the second cleaning brush roller 112 is formed of only conductive fibers. When the raising fibers of the second cleaning brush roller 112 applied with a cleaning bias of negative polarity are formed of only conductive fibers, charge injection from the second cleaning brush roller 112 to toner is facilitated. In this manner, the second cleaning brush roller 112 can equalize the toner on the intermediate transfer belt 8 to the negative polarity. On the other hand, when the raising fibers of the first cleaning brush roller 102 and the third cleaning brush roller 122 have core-sheath structures, charge injection into the toner can be suppressed, thus suppressing positive charging of the toner on the intermediate transfer belt 8. Such a configuration can suppress occurrence of toner not electrostatically removed with the first cleaning brush roller 102 and the third cleaning brush roller 122.
The cleaning brush rollers 102, 112, and 122 are arranged to dig into the intermediate transfer belt 8 by 1 mm. The cleaning brush rollers 102, 112, and 122 are rotated by a driving unit such that the raising fibers move in a direction (counter direction) opposing the moving direction of the intermediate transfer belt 8 at a contact position. At the contact position, the cleaning brush rollers 102, 112, and 122 are rotated to move the rising fibers in the counter direction so that a difference in linear velocity between the intermediate transfer belt 8 and each of the cleaning brush rollers 102, 112, and 122 can be increased. In this manner, a probability of contact to the raising fibers increases in a period until a certain position of the intermediate transfer belt 8 passes through contact areas to the cleaning brush rollers 102, 112, and 122, and the toner can be preferably removed from the intermediate transfer belt 8.
In this embodiment, each of the collection rollers 103, 113, and 123 are made of stainless steel (SUS). In some embodiments, the collection rollers 103, 113, and 123 are made of any other material capable of achieving the following function. The function is to transfer toner adhered to the cleaning brush rollers 102, 112, and 122, from the cleaning brush rollers 102, 112, and 122 to the collection rollers 103, 113, and 123 by potential gradient between the raising fibers and the collection rollers 103, 113, and 123. For example, in some embodiments, each of the collection rollers has a roller resistance log R of from 12Ω to 13Ω obtained by, e.g., covering a conductive metal core with a high-resistance elastic tube having a size of several micrometers to 100 micrometers or coating the conductive metal core with an insulator. Using the stainless steel (SUS) rollers as the collection rollers allows cost reduction or suppression of an application voltage to a low level, and electric power saving can be advantageously achieved. On the other hand, setting the roller resistance log R to be 12Ω to 13Ω allows suppression of electric charge injection into toner in collection of the toner in the collection rollers. As a result, the polarity of toner becomes the same as the polarity of the voltage applied to the collection rollers, thus suppressing a reduction in toner collection efficiency.
Conditions of the cleaning brush rollers 102, 112, and 122 are as follows.
Material of brush: conductive polyester (having a core-sheath structure in which the interior of fiber is made of conductive carbon and the surface of fiber is made of polyester)
Resistance of brush: 10E6Ω to 10E8Ω
Planting density of brush fibers: one hundred thousand per square inch
Diameter of brush fiber: about 25 μm to about 35 μm
Flattening of brush edges: None
Brush diameter φ: 14 mm to 22 mm
Depth of brush fibers digging into the intermediate transfer belt 8: 1 mm
The cleaning bias supplied to the first cleaning brush roller 102 is set to such a value that a good cleaning performance can be obtained when a large amount of post-transfer residual toner arise on the intermediate transfer belt 8. The cleaning bias supplied to the second cleaning brush roller 112 is set to a relatively high absolute value so as to inject charges to toner on the intermediate transfer belt 8. Planting density of brush fibers, resistance of brush, fiber diameter, voltage applied, fiber type, and depth at which brush fibers dig into the intermediate transfer belt 8 can be optimized according to a system used, and are not limited to the above-described values. Examples of usable fiber type include nylon, acryl, polyester, and so on.
Conditions of the collection rollers 103, 113, and 123 are as follows.
Material of cored bar of collection roller: SUS 303
Depth of brush fibers digging into collection roller: 1.5 mm
Material of the collection rollers, the depth of brush fibers digging into each collection roller, voltage applied can be optimized for a system used, and are not limited to the above-described values.
Conditions of the scraping blades (104, 114, and 124) are as follows.
Material of the scraping blades: SUS 304
Contact angle of blade: 20°
Thickness of blade: 0.1 mm
Depth of blade digging into collection roller: 1.0 mm
The contact angle of blade, the thickness of blade, and the depth of blade digging into collection roller can be optimized for a system used, and are not limited to the above-described values.
In
Post-transfer residual toner on the intermediate transfer belt 8, which has not been removed with the first cleaning brush roller 102, includes, for example, toner of negative polarity or weakly charged toner of positive polarity. Such post-transfer residual toner is transported to a contact position at which the intermediate transfer belt 8 contacts the second cleaning brush roller 112. The second cleaning brush roller 112 is applied with a voltage of the same polarity (negative polarity) as the regular charging polarity of toner. By charge injection or electric discharge, the polarity of toner on the intermediate transfer belt 8 is unified to negative polarity. At the same time, by action of an electric field formed by a difference in surface potential between the intermediate transfer belt 8 and the second cleaning brush roller 112, toner charged with negative polarity on the intermediate transfer belt 8 is electrostatically transferred into the brush of the second cleaning brush roller 112. Then, after electrostatically transferred to the second collection roller 113, the transferred residual toner is scraped off from the second collection roller 113 with the second scraping blade 114 and transported to a toner storage part of the second cleaning sub-unit 111 with the second transport screw 115.
Toner of negative polarity having not been removed with the second cleaning brush roller 112 is conveyed to a contact position at which the intermediate transfer belt 8 contacts the third cleaning brush roller 122, with movement of the intermediate transfer belt 8. The amount of residual toner of negative polarity conveyed as described above is quite small. Such residual toner is electrostatically transferred onto the third cleaning brush roller 122 and the third collection roller 123 in turn, and is scraped off from the third collection roller 123 with the third scraping blade 124. Then, residual toner is transported to a toner storage part of the third cleaning sub-unit 121 with the third transport screw 125.
The first left support 151 supports a left lateral end of the first sub-unit casing 106 of the first cleaning sub-unit 101 in a short direction of the first sub-unit casing 106, from a lower side in a vertical direction. More specifically, the first left support 151 allows movement of the left lateral end of the first sub-unit casing 106 in the short direction while supporting the left lateral end of the first sub-unit casing 106 such that the first sub-unit casing 106 can slide and move in the longitudinal direction of the first sub-unit casing 106 (which is a direction perpendicular to a face of a paper sheet on which
The first right support 152 supports a right lateral end of the first sub-unit casing 106 of the first cleaning sub-unit 101 in a short direction of the first sub-unit casing 106, from a lower side in a vertical direction. More specifically, the first right support 152 has a receive portion to receive the right lateral end of the first sub-unit casing 106 in a state of extending in the longitudinal direction of the first sub-unit casing 106 and support the left lateral end so as to be slidable in the longitudinal direction. Besides the receive portion, the first right support 152 has a left side wall located at a left side of the right lateral end of the first sub-unit casing 106 and a right side wall located at a right side of the right lateral end of the first sub-unit casing 106. The right lateral end of the first sub-unit casing 106 is inserted between the left side wall and the right side wall of the first right support 152. The distance between the left side wall and the right side wall is set to be larger than a length of the right lateral end of the first sub-unit casing 106 in the short direction. Accordingly, as illustrated in
In such a configuration, the size of the first sub-unit casing 106 serving as a holder in the short direction might become larger than the designed size within a movable range of the first sub-unit casing 106. In such a case, the first sub-unit casing 106 can be inserted between the first left support 151 and the first right support 152 and supported with the first left support 151 and the first right support 152. Thus, even if the first sub-unit casing 106 has a dimensional error or extends in the short direction, the first cleaning sub-unit 101 can be installed to the sub-unit holder casing 150.
The second left support 153 supports a left lateral end of the second sub-unit casing 116 of the second cleaning sub-unit 111 in a short direction of the second sub-unit casing 116, from a lower side in a vertical direction. The second left support 153 allows movement of the left lateral end of the second sub-unit casing 116 in the short direction while supporting the left lateral end of the second sub-unit casing 116 such that the second sub-unit casing 116 can slide and move in the longitudinal direction of the second sub-unit casing 116. The second right support 154 supports a right lateral end, the other end of the second sub-unit casing 116 in the short direction of the second sub-unit casing 116, from a lower side in the vertical direction. The second right support 154 has a receive portion to receive the right lateral end of the second sub-unit casing 116 in a state of extending in the longitudinal direction of the second sub-unit casing 116 and support the left lateral end so as to be slidable in the longitudinal direction. Besides the receive portion, the second right support 154 further has a left side wall and a right side wall. The right lateral end of the second sub-unit casing 116 is inserted between the left side wall and the right side wall of the second right support 154. The distance between the left side wall and the right side wall is set to be larger than a length of the right lateral end of the first sub-unit casing 106 in the short direction. Accordingly, as illustrated in
For such a configuration, even if the second sub-unit casing 116 has a dimensional error or extends in the short direction, the second cleaning sub-unit 111 can be installed to the sub-unit holder casing 150.
The third left support 155 supports a left lateral end, one end of the third sub-unit casing 126 of the third cleaning sub-unit 121 in a short direction of the third sub-unit casing 126, from a lower side in a vertical direction. The third left support 155 allows movement of the left lateral end of the third sub-unit casing 126 in the short direction while supporting the left lateral end of the third sub-unit casing 126 such that the third sub-unit casing 126 can slide and move in the longitudinal direction of the third sub-unit casing 126. The third right support 156 supports a right lateral end, the other end of the third sub-unit casing 126 in the short direction of the third sub-unit casing 126, from a lower side in the vertical direction. The third right support 156 has a receive portion to receive the right lateral end of the third sub-unit casing 126 in a state of extending in the longitudinal direction of the third sub-unit casing 126 and support the left lateral end so as to be slidable in the longitudinal direction. Besides the receive portion, the third right support 156 further has a left side wall and a right side wall. The right lateral end of the third sub-unit casing 126 is inserted between the left side wall and the right side wall of the third right support 156. The distance between the left side wall and the right side wall is set to be larger than a length of the right lateral end of the third sub-unit casing 126 in the short direction. Accordingly, as illustrated in
For such a configuration, even if the third sub-unit casing 126 has a dimensional error or extends in the short direction, the third cleaning sub-unit 121 can be installed to the sub-unit holder casing 150.
The first cleaning sub-unit 101, the second cleaning sub-unit 111, and the third cleaning sub-unit 121 are pushed and installed into the sub-unit holder casing 150 while being moved to slide from a front side to a rear side in a direction perpendicular to a surface of a paper sheet on which
A circular toner storage 129 of the third cleaning sub-unit 121 passes through the third storage receiving hole 162c of the back side plate 160. The toner storage 129 protrudes in a cylindrical shape beyond the back side plate of the third sub-unit casing of the third cleaning sub-unit 121. A clearance is disposed between an inner wall of the third storage receiving hole 162c and the toner storage 129. Passing of the toner storage 129 through the third storage receiving hole 162c of the back side plate 160 allows the following operation. For example, by rotating the toner storage 129 screwed on the back side plate in a state in which the belt cleaning device 100 is removed from the apparatus body, the toner storage 129 can be removed from the back side plate of the third sub-unit casing. Then, interior waste toner can be discarded.
A third cleaning-bias pin 127a of the third cleaning sub-unit 121 passes through the third cleaning-bias-pin receiving hole 165c of the back side plate 160. The third cleaning-bias pin 127a protrudes backward beyond the back side plate of the third sub-unit casing and conducts the third cleaning brush roller 122 via a metal bearing. A clearance is disposed between an inner wall of the third cleaning-bias-pin receiving hole 165c and the third cleaning-bias pin 127a. Passing the rear end of the third cleaning-bias pin 127a through the third cleaning-bias-pin receiving hole 165c allows the following operation. For example, as illustrated in
In
In
A third back sub-positioning pin 128b of the third cleaning sub-unit 121 is fitted in the third sub-positioning-pin receiving hole 164c of the back side plate 160. The third back sub-positioning pin 128b protrudes beyond the back side plate of the third sub-unit casing of the third cleaning sub-unit 121. Of four inner walls, i.e., upper, lower, left, and right inner walls of the third sub-positioning-pin receiving hole 164c, no clearance is disposed between the third back sub-positioning pin 128b and each of the upper and lower inner walls of the third sub-positioning-pin receiving hole 164c. By contrast, a clearance is disposed between the third back sub-positioning pin 128b and each of the left and right inner walls of the third sub-positioning-pin receiving hole 164c.
As illustrated in
As illustrated in
The positioning of a rear end of the third sub-unit casing 126 in the longitudinal direction is completed at the following timing. That is, when the bottom portion of the third back main-positioning pin 128a closely contacts the entire inner wall of the third main-positioning-pin receiving hole 163c and the bottom portion of the third back sub-positioning pin 128b closely contacts the entire inner wall of the third sub-positioning-pin receiving hole 164c, the rear end of the third sub-unit casing 126 is positioned in the longitudinal direction. A bottom of the rear end of the third sub-unit casing 126 thus positioned floats up from the third left support 155 or the third right support 156.
In
In the above description, the relation between the components at the rear end of the third cleaning sub-unit 121 and the holes of the back side plate 160 is described. The same goes for the relation between components at the rear end of the first cleaning sub-unit 101 and corresponding holes of the back side plate 160. The same also goes for the relation between components at the rear end of the second cleaning sub-unit 111 and corresponding holes of the back side plate 160.
In the belt cleaning device, as illustrated in
A first sub-unit faceplate 141a is fixed at the front side of the front side plate 140 with a bolt. Each of the first sub-unit faceplate 141a and the front side plate 140 includes a first main-positioning-pin receiving hole. The first main-positioning-pin receiving hole of the first sub-unit faceplate 141a and the front side plate 140 are communicated with each other. Each of the first sub-unit faceplate 141a and the front side plate 140 includes a first sub-positioning-pin receiving hole. The first sub-positioning-pin receiving hole of the first sub-unit faceplate 141a and the front side plate 140 are communicated with each other.
A first front main-positioning pin 108c and a first front sub-positioning pin 108d protrudes from the front side plate of the sub-unit casing of the first cleaning sub-unit 101. When the first sub-unit faceplate 141a is secured to the front side plate 140 of the sub-unit holder casing 150, the front end of the first cleaning sub-unit 101 is positioned as follow. In other words, the first front sub-positioning pin 108d of the first cleaning sub-unit 101 fits in the first sub-positioning-pin receiving holes of the front side plate 140 and the first sub-unit faceplate 141a. Simultaneously, the first front main-positioning pin 108c of the first cleaning sub-unit 101 fits in the first main-positioning-pin receiving holes of the front side plate 140 and the first sub-unit faceplate 141a. Thus, positioning is performed.
In this positioning, a floor of the front end of the sub-unit casing of the first cleaning sub-unit 101 floats up from the first left support (151 in
The first sub-unit faceplate 141a supports a first drive transmitter 146a including, e.g., a first collection gear 142a, a first screw gear 143a, a first cleaning pulley gear 144a, and a first relay pulley gear 145a. Each of the first collection gear 142a, the first screw gear 143a, the first cleaning pulley gear 144a, the first relay pulley gear 145a is rotatably supported with the first sub-unit faceplate 141a.
The first collection gear 142a is coupled with a shaft of the first collection roller 103 with a coupling at a back side of the first sub-unit faceplate 141a. The first screw gear 143a is coupled with a shaft of the first transport screw 105 with a coupling at the back side of the first sub-unit faceplate 141a. The first cleaning pulley gear 144a is coupled with a member of the first cleaning brush roller 102 with a coupling at the back side of the first sub-unit faceplate 141a.
A gear portion of the first relay pulley gear 145a engages the first collection gear 142a. Thus, the rotation drive of the first relay pulley gear 145a is transmitted to the first collection gear 142a to rotate the first collection roller 103 inside the first cleaning sub-unit 101. As the first collection gear 142a is rotated, the first screw gear 143a engaging the first collection gear 142a rotates, thus rotating the first transport screw 105 inside the first cleaning sub-unit 101.
A timing belt is stretched over the first relay pulley gear 145a and the first cleaning pulley gear 144a. Thus, the rotation drive of the first cleaning pulley gear 144a is transmitted to the first relay pulley gear 145a. As the first cleaning pulley gear 144a rotates, the first cleaning brush roller 102 is rotated inside the first cleaning sub-unit 101.
A drive receive coupling 181a serving as a joint coupler is secured at the front edge of the first cleaning pulley gear 144a so as to rotate coaxially with the first cleaning pulley gear 144a. A drive receive coupling 181b serving as a joint coupler is secured at a front edge of a second cleaning pulley gear 144b so as to rotate coaxially with the second cleaning pulley gear 144b. A drive receive coupling 181c serving as a joint coupler is secured at a front edge of a third cleaning pulley gear 144c so as to rotate coaxially with the third cleaning pulley gear 144c.
In the above description, the positioning of the front end of the first cleaning sub-unit 101 in the longitudinal direction is described. In the same manner, the front end of the second cleaning sub-unit 111 or the third cleaning sub-unit 121 is positioned. In the above description, the first drive transmitter 146a of the first cleaning sub-unit 101 is described. Likewise, a second drive transmitter 146b of the second cleaning sub-unit 111 or a third drive transmitter 146c of the third cleaning sub-unit 121 has a similar configuration to that of the first drive transmitter 146a of the first cleaning sub-unit 101.
As illustrated in
In this printer, a drive transmission system of the belt cleaning device 100 is centered on the front side of the front side plate 140. By contrast, joint caps 191 to apply cleaning bias and collection bias are centered on the rear side of the back side plate 160. Thus, a layout of preventing joint caps or bias pins applied with high voltage from approaching to the rotation metal shaft of drive transmission system is achieved, thus preventing electric discharge between the rotation metal shaft and the joint caps or bias pins.
Next, a configuration of an image forming apparatus according to an embodiment of this disclosure is described below.
A belt is stretched over and around the first relay gear 187 and the first relay gear 187. The rotation drive of the first relay gear 187 is transmitted to the second relay gear 188. A rotary shaft of the second relay gear 188 engages one gear of a gear train including multiple gears within the casing 186 of the transmission assembly 185. The gears of the gear train include, e.g., a first output gear 189a, a second output gear 189b, and a third output gear 189c. The rotation drive of the second relay gear 188 is also transmitted to the first output gear 189a, the second output gear 189b, and the third output gear 189c. Each of the first output gear 189a, the second output gear 189b, and the third output gear 189c protrudes beyond the back face of the casing 186 via a through-hole of the casing 186. A drive output coupling 190a serving as a joint coupler is secured to a protruding portion of the first output gear 189a protruding beyond the casing 186 so as to rotate coaxially with the first output gear 189a. A drive output coupling 190b serving as a joint coupler is secured to a protruding portion of the second output gear 189b protruding beyond the casing 186 so as to rotate coaxially with the second output gear 189b. A drive output coupling 190c serving as a joint coupler is secured to a protruding portion of the third output gear 189c protruding beyond the casing 186 so as to rotate coaxially with the third output gear 189c.
When the transmission assembly 185 is mounted on the front side plate 140 of the belt cleaning device 100, the drive output coupling 190a of the first output gear 189a of the transmission assembly 185 is coaxially coupled with the drive receive coupling (181a in
In
In such install and removal operations, the operator is not forced to remove the belt stretched around and between the two cleaning sub-units. Accordingly, when a plurality of cleaning sub-units is installed to or removed from the sub-unit holder casing 150, the operator is not forced to attach or remove multiple belts, and it is enough to attach or remove the transmission assembly 185 relative to the sub-unit holder casing 150 only once. Such a configuration enhances work performance of the operator in install and removal of the plurality of cleaning sub-units relative to the sub-unit holder casing 150.
In this embodiment, each of the drive output coupling 190a to 190c serving as joint couplers and the drive receive couplings 181a to 181c serving as joint couplers are is made of insulating resin. Such a configuration prevents cleaning bias applied to the cleaning brush rollers 102, 112, and 122 from leaking to the outside via the couplings.
For the image forming apparatus, the transmission assembly 185 is installed or removed relative to the front side plate 140 located at an edge in a direction in which the cleaning sub-units 191, 111, and 121 are pulled out from the sub-unit holder casing 150. Such a configuration allows installation and removal of the transmission assembly 185 relative to the sub-unit holder casing 150 without removing the entire belt cleaning device 100 from the apparatus body of the image forming apparatus. Accordingly, the cleaning sub-units can be installed into and removed from the sub-unit holder casing 150 without pulling out the entire belt cleaning device 100 from the apparatus body, thus enhancing the operation performance in installation and removal.
As described above, in
By contrast, as illustrated in
Next, a configuration of an image forming apparatus according to another embodiment of this disclosure is described below. Unless specifically described, the configuration of the image forming apparatus in this embodiment is similar to, if not the same as, that of the image forming apparatus according to the above-described embodiment.
The three studs 195 have a sturdy structure and is unlikely to deform. As compared with a configuration in which the transmission assembly 185 are supported with legs (e.g., the legs 186a), such a configuration suppresses a reduction in positioning accuracy between the transmission assembly 185 and the three drive transmitter 146a to 146c disposed at the body of the belt cleaning device 100. Thus, operation performance in mounting the transmission assembly 185 can be enhanced.
The length of the studs 195 is preferably set as follow. For example, the length of each of the studs 195 is preferably set to not less than a total of a distance from the front face (edge) of the front side plate 140a leading edge of the drive receive coupling (181a to 181c) and a distance from the back face of the transmission assembly 185 to the drive output coupling (190a to 190c). It is to be noted that a length slightly value than the total may be set as a minimum length. For example, the minimum length is a value obtained by subtracting, from the total, a depth of a recess of one of the drive receive coupling (181a to 181c) and the drive output coupling (190a to 190c) that receives the other. Accordingly, in the image forming apparatus in this embodiment, the length of each of the studs 195 is set to be greater than the value.
In consideration of dimensional errors of components, couplings are preferably configured to transmit drive even if the couplings are slightly shifted in the rotation axial direction. For the image forming apparatus according to this embodiment, for example, the length of the stud 195 is set to be greater than the above-described value by 0.4 mm.
The studs 195 are preferably three or more. The three or more studs 195 allow the transmission assembly 185 to be supported on a plane constituted of leading edges of the three or more studs 195. For the image forming apparatus according to this embodiment, as illustrated in
The studs 195 preferably have a certain degree or more of strength to stably support the transmission assembly 185 against a force generated by the driving. Therefore, the studs 195 are preferably a cylindrical stud including metal, such as iron, aluminum, and/or stainless steel, having a diameter of 5 mm or more. For the image forming apparatus according to this embodiment, the studs 195 has a cylindrical shape of a diameter of 5 mm or more and is made of free-cutting steel. A deformation amount at which the stud 195 deforms when applied with a load of 6 [N] is 0.1 mm or less.
The image forming apparatus according to this embodiment employs the studs 195 made of conductive material and applies a high voltage of X [kv] to the cleaning brush roller. The studs 195 are disposed at positions away from the cleaning brush roller by 2×X mm to prevent occurrence of electric discharge between the cleaning brush roller and each of the studs 195.
The above description is just an example, and an image forming apparatus according to embodiments of this disclosure can exert, for example, an effect in each of the following aspects.
[Aspect A]
A unit device is detachably attachable relative to a machine body. The unit device includes a plurality of sub units each including a driver to be driven by a driving force received and a sub-unit holder to hold the plurality of sub-units. The unit device further includes a detachable transmission assembly. The transmission assembly includes a driving-force receive rotator to receive a rotation driving force transmitted from an external unit and a plurality of drive transmission rotators to transmit the rotation driving force received by the driving-force receive rotator to a plurality of drive receive rotators of the plurality of sub units. Each of the plurality of the drive receive rotators and the plurality of drive transmission rotators has a joint coupler to couple each of the plurality of drive receive rotators with a corresponding one of the plurality of drive transmission rotators.
For such a configuration, first, an operator removes the transmission assembly from the sub-unit holder ahead of removal of the plurality of sub units from the sub-unit holder. As a result, joint couplers of the drive receive rotators of the plurality of sub units are decoupled from joint couplers of the drive transmission rotators disposed at the transmission assembly so as to correspond to the drive receive rotators. Thus, the sub units become separately removable from the sub-unit holder, and the operator can remove a desired one of the sub units from the sub-unit holder. To install the sub unit to the sub-unit holder, the operator the above-described steps in the opposite order. In such install and removal operations, the operator is not forced to attach or remove the belt stretched around and between the two sub cleaning units. Accordingly, when a plurality of cleaning sub-units is installed to or removed from the sub-unit holder, the operator is not forced to attach or remove multiple belts, and it is enough to attach or remove the transmission assembly relative to the sub-unit holder only once. Such a configuration enhances work performance of the operator in install and removal of the plurality of sub-units relative to the sub-unit holder.
[Aspect B]
According to Aspect B, a cleaning device (e.g., the belt cleaning device 100) includes a cleaner (e.g., cleaning brush rollers 102, 112, 122) to scrape off adhered material from a surface of a cleaning target (e.g., intermediate transfer belt 8); a plurality of cleaning sub-units (e.g., cleaning sub-units 101, 111, 121) each including a holder (e.g., sub-unit casings 106, 116, 126) to hold the cleaner and a drive-receive rotator to receive a driving force; a sub-unit holder (e.g., sub-unit holder casing 150) holding the plurality of cleaning sub-units; a detachable transmission assembly (e.g., transmission assembly 185) including a driving-force receive rotator (e.g., first relay gear 187) to receive a driving force from an external unit and a plurality of drive transmission rotators (e.g., output gears 189a to 189c) to transmit the driving force received by the driving-force receive rotator to the drive-receive rotators of the plurality of cleaning sub-units; and a plurality of joint couplers (e.g., drive output couplings 190a to 190c and drive receive couplings 181a to 181c) mounted on the drive-receive rotators and the plurality of drive transmission rotators to couple the drive-receive rotators with the plurality of drive transmission rotators in a rotation axial direction.
Such a configuration enhances work performance of an operator in install and removal of the plurality of cleaning sub-units relative to the body of the belt cleaning device 100.
[Aspect C]
According to Aspect C, in the cleaning device according to Aspect B, the transmission assembly is detachably attachable relative to a body of the cleaning device in the rotational axial direction. Thus, when the transmission assembly is moved in the rotational axial direction and installed to or removed from the sub-unit holder, joint couplers of the drive-receive rotators of the plurality of cleaning sub-units are automatically coupled with or decoupled from joint couplers of the plurality of drive transmission rotators in the transmission assembly.
[Aspect D]
According to Aspect D, in the cleaning device according to Aspect B or C, the plurality of joint couplers is made of insulating material. Such a configuration prevents cleaning bias applied to the cleaner from leaking to the outside via the joint couplers.
[Aspect E]
According to Aspect E, in the cleaning device according to any one of Aspects B to D, the transmission assembly is detachably attachable relative to a body of the cleaning device in the rotational axial direction. For such a configuration, as described in the embodiments of this disclosure, the plurality of cleaning sub-units can be installed into and removed from the sub-unit holder without pulling out the entire belt cleaning device from a body of an image forming apparatus, thus enhancing the operation performance in installation and removal.
[Aspect F]
According to Aspect F, in the cleaning device according to Aspect E, the belt cleaning device has a support (e.g., studs 195) protruding from a surface of the edge of the body (e.g., the front side plate 140) of the belt cleaning device in the direction in which the plurality of cleaning sub-units is pulled out from the sub-unit holder, and the transmission assembly is fixed on the support. As described above, such a configuration can enhance operation performance of an operation in installing the transmission assembly as compared with a configuration in which the transmission assembly is supported with legs of sheet metal.
[Aspect G]
According to Aspect G, in the cleaning device according to Aspect F, a height of the support is greater than a value obtained by subtracting a total of a length from a depth of a recess of one of the plurality of joint couplers to receive another of the plurality of joint couplers from a total of a length from the surface of the edge to a leading edge of the one of the plurality of joint couplers mounted to the drive-receive rotators in the direction and a length from a back face of a body of the transmission assembly to a leading edge of the plurality of drive transmission rotators in the direction. For such a configuration, as described above, the drive receive rotators and the drive transmission rotators can be placed within the length of the support, thus allowing the transmission assembly to be reliably mounted to the body of the belt cleaning device.
[Aspect H]
According to Aspect H, the cleaning device according to Aspect F or G includes three or more joint couplers as the plurality of joint couplers. For such a configuration, as described above, the transmission assembly can be stably supported with protruding edges of the three or more supports.
[Aspect I]
According to Aspect I, in the cleaning device according to any one of Aspects F to H, the support has a cylindrical shape having a diameter of 5 mm or greater and is made of free-cutting steel. Such a configuration effectively suppresses deformation of the support.
[Aspect J]
According to Aspect J, an image forming apparatus includes an image bearer to bear a toner image; an image forming device to form a toner image on a surface of the image bearer; and the cleaning device according to any one of Aspects B to I to scrape off toner as adhered substance on the surface of the image bearer.
Numerous additional modifications and variations are possible in light of the above teachings. It is therefore to be understood that, within the scope of the above teachings, the present disclosure may be practiced otherwise than as specifically described herein. With some embodiments having thus been described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the scope of the present disclosure and appended claims, and all such modifications are intended to be included within the scope of the present disclosure and appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2014-010086 | Jan 2014 | JP | national |
| 2014-133543 | Jun 2014 | JP | national |
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