This patent application is based on and claims priority pursuant to 35 U.S.C. §119 to Japanese Patent Application No. 2012-151891, filed on Jul. 5, 2012, in the Japanese Patent Office, the entire disclosure of which is hereby incorporated by reference herein.
1. Field
Example embodiments generally relate to an image carrier surface treatment device, a process cartridge, and an image forming apparatus, and more particularly, to an image carrier surface treatment device for performing surface treatment of an image carrier and a process cartridge and an image forming apparatus incorporating the image carrier surface treatment device.
2. Discussion of the Background
Related-art image forming apparatuses, such as copiers, facsimile machines, printers, or multifunction printers having two or more of copying, printing, scanning, facsimile, plotter, and other functions, typically form an image on a recording medium according to image data. Thus, for example, a charger uniformly charges a surface of a photoconductive drum serving as an image carrier rotatable in a given direction of rotation; an optical writer emits a light beam onto the charged surface of the photoconductive drum to form an electrostatic latent image on the photoconductive drum according to the image data; a development device supplies toner to the electrostatic latent image formed on the photoconductive drum to render the electrostatic latent image visible as a toner image; the toner image is directly transferred from the photoconductive drum onto a recording medium or is indirectly transferred from the photoconductive drum onto a recording medium via an intermediate transfer belt; finally, a fixing device applies heat and pressure to the recording medium bearing the toner image to fix the toner image on the recording medium, thus forming the image on the recording medium.
Such image forming apparatuses may further include a cleaning blade that removes residual toner failed to be transferred onto the intermediate transfer belt or a recording medium and therefore remaining on the photoconductive drum therefrom and a lubricant supplier that supplies a lubricant onto the photoconductive drum to decrease friction between the photoconductive drum and the cleaning blade sliding thereover, thus reducing abrasion of the photoconductive drum and the cleaning blade.
For example, the lubricant supplier may be disposed downstream from the cleaning blade in the direction of rotation of the photoconductive drum and include a lubricant application roller that rotates in a given direction of rotation and slides over the photoconductive drum; a solid lubricant in contact with the lubricant application roller; a spring that biases the solid lubricant against the lubricant application roller; and a level blade disposed downstream from the lubricant application roller in the direction of rotation of the photoconductive drum and in contact with the photoconductive drum. As the lubricant application roller slides over the solid lubricant and the photoconductive drum, it scrapes a lubricant off the solid lubricant and applies the scraped lubricant onto the photoconductive drum. Thereafter, the level blade levels the lubricant applied on the photoconductive drum into a thin layer.
As the lubricant application roller rotating in the given direction of rotation slides over both the solid lubricant and the photoconductive drum, the lubricant application roller may create vibration. If the vibration is transmitted to the photoconductive drum abutting the lubricant application roller, the toner image formed on the photoconductive drum may be degraded into a faulty toner image such as a streaky toner image produced by periodical vibration of the photoconductive drum.
At least one embodiment may provide an image carrier surface treatment device disposed opposite an image carrier rotatable in a first rotation direction and carrying a toner image. The image carrier surface treatment device includes a roller rotatable in a second rotation direction while contacting an outer circumferential surface of the image carrier. The roller includes a shaft projecting from each lateral end of the roller in an axial direction thereof. A rolling-element bearing is fitted on the shaft of the roller to support and position the roller inside the image carrier surface treatment device.
At least one embodiment may provide a process cartridge detachably attachable to an image forming apparatus and including an image carrier rotatable in a first rotation direction and carrying a toner image. The process cartridge further includes an image carrier surface treatment device disposed opposite the image carrier and including a roller rotatable in a second rotation direction while contacting an outer circumferential surface of the image carrier. The roller includes a shaft projecting from each lateral end of the roller in an axial direction thereof. A rolling-element bearing is fitted on the shaft of the roller to support and position the roller inside the image carrier surface treatment device.
At least one embodiment may provide an image forming apparatus that includes an image carrier rotatable in a first rotation direction to carry a toner image and an image carrier surface treatment device disposed opposite the image carrier and including a roller rotatable in a second rotation direction while contacting an outer circumferential surface of the image carrier. The roller includes a shaft projecting from each lateral end of the roller in an axial direction thereof. A rolling-element bearing is fitted on the shaft of the roller to support and position the roller inside the image carrier surface treatment device.
Additional features and advantages of example embodiments will be more fully apparent from the following detailed description, the accompanying drawings, and the associated claims.
A more complete appreciation of example embodiments and the many attendant advantages thereof will be readily obtained as the same becomes 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 example embodiments 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.
It will be understood that if an element or layer is referred to as being “on”, “against”, “connected to”, or “coupled to” another element or layer, then it can be directly on, against, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, if an element is referred to as being “directly on”, “directly connected to”, or “directly coupled to” another element or layer, then there are no intervening elements or layers present. Like numbers refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Spatially relative terms, such as “beneath”, “below”, “lower”, “above”, “upper”, and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, term such as “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein are interpreted accordingly.
Although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, it should be understood that these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, or section from another region, layer, or section. Thus, a first element, component, region, layer, or section discussed below could be termed a second element, component, region, layer, or section without departing from the teachings of the present invention.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present invention. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “includes” and/or “including”, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
In describing example embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this 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.
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, particularly to
An auto document feeder (ADF) 3 disposed atop the image forming apparatus 1 feeds an original D to a reader 4 situated below the ADF 3. The reader 4 reads an image on the original D into image data. A writer 2 disposed below the reader 4 emits laser beams onto four photoconductive drums 11 of the four process cartridges 10Y, 10M, 10C, and 10K according to the image data sent from the reader 4, thus forming electrostatic latent images on the photoconductive drums 11. The process cartridges 10Y, 10M, 10C, and 10K situated below the writer 2 visualize the electrostatic latent images into yellow, magenta, cyan, and black toner images, respectively. Four primary transfer rollers 16 disposed opposite the photoconductive drums 11 primarily transfer the yellow, magenta, cyan, and black toner images formed on the photoconductive drums 11 onto an intermediate transfer belt 17 such that the yellow, magenta, cyan, and black toner images are superimposed on a same position on the intermediate transfer belt 17, thus forming a color toner image thereon.
A plurality of paper trays 7 situated in a lower portion of the image forming apparatus 1 loads a plurality of recording media (e.g., transfer sheets). A feed roller 8 rotatably mounted on the respective paper trays 7 feeds a recording medium toward a registration roller pair 9. As the registration roller pair 9 feeds the recording medium to a secondary transfer roller 18 disposed opposite the intermediate transfer belt 17, the secondary transfer roller 18 secondarily transfers the color toner image formed on the intermediate transfer belt 17 onto the recording medium. An intermediate transfer belt cleaner 19 disposed opposite the intermediate transfer belt 17 cleans the intermediate transfer belt 17. A fixing device 20 disposed downstream from the secondary transfer roller 18 in a recording medium conveyance direction fixes the color toner image on the recording medium.
A description is provided of an image forming operation performed by the image forming apparatus 1 described above to form a color toner image. Conveyance rollers of the ADF 3 feed an original D placed on an original tray to an exposure glass 5 of the reader 4. Alternatively, a user may place an original D on the exposure glass 5. The reader 4 optically reads an image on the original D through the exposure glass 5. For example, a lamp of the reader 4 emits light onto the image on the original D through the exposure glass 5 such that the light scans the image on the original D. The light reflected by the original D travels through a plurality of mirrors and a lens into a color sensor that forms an image. The color sensor reads the image into image data corresponding to separation colors, that is, red, green, and blue, which is converted into an electric signal. Further, based on the electric signal corresponding to red, green, and blue, an image processor performs processing such as color conversion processing, color correction processing, and space frequency correction processing, thus producing yellow, magenta, cyan, and black image data.
The yellow, magenta, cyan, and black image data created by the reader 4 is sent to the writer 2. The writer 2 emits laser beams (e.g., exposure light) onto the photoconductive drums 11 of the process cartridges 10Y, 10M, 10C, and 10K according to the yellow, magenta, cyan, and black image data, respectively, forming electrostatic latent images thereon. Thus, each of the photoconductive drums 11 serves as an image carrier for carrying an electrostatic latent image.
With reference to
As shown in
In an exposure process, as the charged outer circumferential surface of the photoconductive drum 11 reaches an irradiation position where the writer 2 is disposed opposite the photoconductive drum 11, a light source of the writer 2 emits a laser beam L onto the charged outer circumferential surface of the photoconductive drum 11 according to an electric signal corresponding to yellow image data. Other three light sources of the writer 2 emit laser beams L onto the photoconductive drums 11 of the process cartridges 10M, 10C, and 10K according to electric signals corresponding to magenta, cyan, and black image data, respectively. The laser beams L travel through different optical paths that lead to the photoconductive drums 11 of the process cartridges 10Y, 10M, 10C, and 10K, respectively.
As shown in
Similarly, the writer 2 emits a laser beam L onto the second photoconductive drum 11 from the left in
As shown in
Similarly, the development devices 13 of the process cartridges 10M, 10C, and 10K depicted in
As shown in
Thereafter, as the outer circumferential surface of the photoconductive drum 11 passes through a lubrication position where a lubricant supplier 15 is disposed opposite the photoconductive drum 11, the lubricant supplier 15 serving as an image carrier surface treatment device supplies a lubricant to the outer circumferential surface of the photoconductive drum 11. Thereafter, as the outer circumferential surface of the photoconductive drum 11 passes through a discharging position where a discharger is disposed opposite the photoconductive drum 11, the discharger discharges the outer circumferential surface of the photoconductive drum 11. Thus, a series of image forming processes performed on the photoconductive drum 11 is completed.
On the other hand, as shown in
At a cleaning position where the intermediate transfer belt cleaner 19 is disposed opposite the intermediate transfer belt 17, the intermediate transfer belt cleaner 19 removes residual toner failed to be transferred onto the recording medium and therefore remaining on the intermediate transfer belt 17 therefrom. The removed toner is collected into the intermediate transfer belt cleaner 19. Thus, a series of transfer processes, that is, the primary transfer process and the secondary transfer process, performed on the intermediate transfer belt 17 is completed.
The recording medium is conveyed from one of the paper trays 7 to a secondary transfer nip formed between the intermediate transfer belt 17 and the secondary transfer roller 18 through the registration roller pair 9. For example, the recording medium loaded in the paper tray 7 is picked up and conveyed by the feed roller 8 through a conveyance guide to the registration roller pair 9 (e.g., a timing roller pair). The registration roller pair 9 conveys the recording medium to the secondary transfer nip at a time when the color toner image formed on the intermediate transfer belt 17 reaches the secondary transfer nip.
The recording medium bearing the color toner image is guided by a conveyance belt to the fixing device 20. The fixing device 20 includes a fixing belt and a pressing roller pressed against the fixing belt to form a fixing nip therebetween where the color toner image is fixed on the recording medium. Thereafter, the recording medium bearing the fixed color toner image is discharged by an output roller pair onto an outside of the image forming apparatus 1. Thus, a series of image forming processes performed by the image forming apparatus 1 is completed.
With reference to
As shown in
A detailed description is now given of a construction of the photoconductive drum 11.
The photoconductive drum 11 is a negatively charged, organic photoconductor or photoreceptor. The photoconductive drum 11 includes a drum-shaped conductive support and a photosensitive layer mounted thereon. For example, the photoconductive drum 11 is constructed of a base layer serving as the conductive support; an insulating layer serving as an underlying layer; a charge generation layer or a charge transport layer serving as the photosensitive layer; and a protective layer serving as a surface layer, which are layered in this order.
A detailed description is now given of a construction of the charger 12.
The charger 12 includes the charging roller 12a and a charger cleaning roller 40. The charging roller 12a is constructed of a conductive metal core and an elastic layer coating an outer circumference of the metal core and having a medium resistance. As a power supply applies a given voltage, that is, a superimposed voltage of an alternating current voltage and a direct current voltage, to the charging roller 12a, the charging roller 12a uniformly charges the outer circumferential surface of the photoconductive drum 11 disposed opposite the charging roller 12a. According to this example embodiment, a compression spring biases the charging roller 12a against the photoconductive drum 11, bringing the charging roller 12a into contact with the photoconductive drum 11 with pressure therebetween. Alternatively, the charging roller 12a may be disposed opposite the photoconductive drum 11 with a slight interval therebetween without contacting the photoconductive drum 11. The charger cleaning roller 40 pressingly contacting the charging roller 12a cleans an outer circumferential surface of the charging roller 12a.
A detailed description is now given of a construction of the development device 13.
The development device 13 is constructed of a development roller 13a disposed opposite the photoconductive drum 11; a primary conveyance screw 13b disposed opposite the development roller 13a; a secondary conveyance screw 13c disposed opposite the primary conveyance screw 13b via a partition; and a doctor blade 13d disposed opposite the development roller 13a. The development roller 13a is constructed of a magnet fixedly provided inside the development roller 13a to create a magnetic pole on a circumferential surface of the development roller 13a and a sleeve rotatable around the magnet. As the magnet creates a plurality of magnetic poles on the sleeve of the development roller 13a, the development roller 13a bears a developer G.
The development device 13 contains the two-component developer G containing carrier particles C and toner particles T, that is, toner. The toner particle T is a spherical particle having a roundness of about 0.93 or more and a ratio between a weight mean diameter D4 and a number mean diameter D1 (D4/D1) in a range of from about 1.00 to about 1.40. The roundness of the toner particle T defines a circumferential length of a circle having an area identical to an area of a projected particle with respect to a circumferential length of a projected particle image. The roundness of the toner particles T is calculated based on a value measured with a flow particle image analyzer FPIA-2000 manufactured by Sysmex Corporation. The weight mean diameter D4 and the number mean diameter D1. of the toner particle T are measured with a particle diameter measurement device SD2000 manufactured by Hosokawa Micron Corporation.
A detailed description is now given of a construction of the cleaner 14.
The cleaner 14 includes the cleaning blade 14a serving as a blade for cleaning the outer circumferential surface of the photoconductive drum 11 by contacting it and the cleaning roller 14b serving as a roller for cleaning the outer circumferential surface of the photoconductive drum 11 as the cleaning roller 14b in contact with the outer circumferential surface of the photoconductive drum 11 rotates counterclockwise in
The cleaning blade 14a is made of rubber such as urethane rubber and in contact with the outer circumferential surface of the photoconductive drum 11 with a given angle and a given pressure. Thus, the cleaning blade 14a mechanically scrapes an adhesive substance adhered to the photoconductive drum 11 off the photoconductive drum 11 into the cleaner 14. For example, the adhesive substance may be residual toner failed to be transferred onto the intermediate transfer belt 17 and therefore remaining on the photoconductive drum 11, paper dust produced from the recording medium, a corona product carried by the photoconductive drum 11 as the charging roller 12a performs discharge, an additive added to the toner particles T, and the like. The cleaning blade 14a is directed to the photoconductive drum 11 in a direction counter to the rotation direction R1 of the photoconductive drum 11.
The cleaning roller 14b is a brush roller constructed of a metal shaft 14b1 (e.g., a metal core) and bristles 14b2 surrounding the shaft 14b1. As a driver drives and rotates the cleaning roller 14b in the rotation direction R3, the bristles 14b2 of the cleaning roller 14b slide over the outer circumferential surface of the photoconductive drum 11. Thus, the cleaning roller 14b mechanically scrapes residual toner off the photoconductive drum 11 into the cleaner 14. The cleaning roller 14b disposed upstream from the cleaning blade 14a in the rotation direction R1. of the photoconductive drum 11 complements the cleaning blade 14a to clean the photoconductive drum 11. The cleaner 14 having the construction described above serves as an image carrier surface treatment device disposed opposite the photoconductive drum 11 to perform surface treatment of the photoconductive drum 11, thus increasing the lifespan of the photoconductive drum 11.
With reference to
A detailed description is now given of a construction of the lubricant application roller 15a.
The lubricant application roller 15a is a roller constructed of a metal shaft 15a1 a metal core) and the elastic foam layer 15a2 coating the shaft 15a1 and made of polyurethane foam or urethane foam. As the elastic foam layer 15a2 of the lubricant application roller 15a in contact with the outer circumferential surface of the photoconductive drum 11 rotates counterclockwise in
A description is provided of a method for manufacturing the lubricant application roller 15a.
Polyurethane foam to be produced into the elastic foam layer 15a2 is formed into a block. The block is cut into a primary piece having a given shape and its surface is ground. A core (e.g., a metal core) to be produced into the shaft 15a1 is inserted into the primary piece of polyurethane foam. As the primary piece of polyurethane foam is rotated, a grind blade in contact with the primary piece moves parallel to an axial direction of the metal core until the grind blade cuts the primary piece into a sponge having a given thickness by traverse grinding. Thus, the elastic foam layer 15a2 is manufactured. Before the metal core is inserted into the primary piece of polyurethane foam, an adhesive may be applied to the metal core to facilitate adhesion of the metal core to the primary piece. Further, during traverse grinding, the rotation speed of the primary piece of polyurethane foam and the moving speed of the grind blade may be changed to produce uneven surface asperities on the elastic foam layer. The method for manufacturing the lubricant application roller 15a is not limited to the above. For example, alternatively, a polyurethane foam material is injected into a mold accommodating the metal core and foamed and hardened.
A detailed description is now given of a configuration of the lubricant application roller 15a.
As shown in
A detailed description is now given of a configuration of the solid lubricant 15b.
The solid lubricant 15b is made of aliphatic acid zinc metal containing an inorganic lubricant. For example, the aliphatic acid zinc metal may contain at least zinc stearate. The inorganic lubricant may contain at least one of talc, mica, and boron nitride. The zinc stearate may be typical lamella crystalline powder. Lamella crystal has a self-assembled layer structure produced with amphipathic molecule. Accordingly, as the lamella crystal receives a shear force, it may be broken along an interlayer and subject to slippage. Consequently, the lamella crystal applied on the outer circumferential surface of the photoconductive drum 11 decreases friction between the photoconductive drum 11 and a component or a substance sliding thereover. Since the lamella crystal, upon receiving a shear force, spreads over and coats the outer circumferential surface of the photoconductive drum 11 evenly, the lubricant containing the lamella crystal, even with a small amount thereof, coats the outer circumferential surface of the photoconductive drum 11 effectively. Accordingly, the lubricant coats the outer circumferential surface of the photoconductive drum 11 relatively evenly, protecting the photoconductive drum 11 against electrical stress during the charging process precisely. The inorganic lubricant having a plated structure such as talc, mica, and boron nitride prevents the toner and the lubricant from passing under the cleaning blade 14a and reaching and staining the charging roller 12a.
A description is provided of a method for manufacturing the solid lubricant 15b.
Dissolved powder is put into a mold and compressed, thus being solidified into a substantial prism. The method simplifies production facility, resulting in reduced manufacturing costs.
A detailed description is now given of a configuration of the level blade 15d.
The level blade 15d is a plate made of rubber such as urethane rubber and in contact with the outer circumferential surface of the photoconductive drum 11 at a given angle and a given pressure therebetween. The level blade 15d is disposed downstream from the cleaning blade 14a in the rotation direction R1 of the photoconductive drum 11. The level blade 15d levels the lubricant supplied from the lubricant application roller 15a onto the photoconductive drum 11 into a thin lubricant layer that coats the photoconductive drum 11 evenly with a proper amount. As the lubricant application roller 15a applies the lubricant scraped off the solid lubricant 15b onto the outer circumferential surface of the photoconductive drum 11, the photoconductive drum 11 bears a powdery lubricant that lubricates the photoconductive drum 11 insufficiently. To address this circumstance, the level blade 15d levels the powdery lubricant into the thin lubricant layer. Thus, the level blade 15d produces the thin lubricant layer that coats and lubricates the photoconductive drum 11. That is, the powdery lubricant that lubricates the photoconductive drum 11 insufficiently is transformed into the thin lubricant layer that lubricates the photoconductive drum 11 sufficiently.
The level blade 15d is directed to and brought into contact with the outer circumferential surface of the photoconductive drum 11 in a direction counter to the rotation direction R1 of the photoconductive drum 11 with a pressure in a range of from about 10 g/cm2 to about 60 g/cm2 and a contact angle θ in a range of from about 75 degrees to about 90 degrees. The level blade 15d brought into contact with the photoconductive drum 11 in the direction counter to the rotation direction R1 of the photoconductive drum 11 thins the lubricant on the photoconductive drum 11 effectively. The contact angle θ defines an angle formed between a hypothetical line passing through an edge of the level blade 15d abutted against and bent by the photoconductive drum 11 and a tangent to the photoconductive drum 11, that is, a line perpendicular to a normal, at an abut point where the edge of the level blade 15d abuts against the photoconductive drum 11.
The two separate blades, that is, the cleaning blade 14a and the level blade 15d, contact the photoconductive drum 11 to clean and lubricate the photoconductive drum 11 precisely. The lubricant supplied to the photoconductive drum 11 reduces abrasion and wear of the cleaning blade 14a and the level blade 15d caused by friction between the photoconductive drum 11 and the cleaning blade 14a and friction between the photoconductive drum 11 and the level blade 15d. A surface of an edge of the cleaning blade 14a and the level blade 15d that contacts the photoconductive drum 11 is coated with fluoroplastic, for example, to reduce friction between the cleaning blade 14a and the photoconductive drum 11 and between the level blade 15d and the photoconductive drum 11. Accordingly, frictional abrasion and wear of the cleaning blade 14a and the level blade 15d are reduced, enhancing durability of the cleaning blade 14a and the level blade 15d.
With reference to
With reference to
The development roller 13a rotates clockwise in
The toner particles T attracted to carrier particles C by frictional charging, together with the carrier particles C, move onto the development roller 13a. As the development roller 13a rotates in the rotation direction R5, the developer G containing the toner particles T and the carrier particles C carried by the development roller 13a reaches the doctor blade 13d. After the doctor blade 13d adjusts an amount of the developer G carried by the development roller 13a, the developer G reaches the development position where the development roller 13a is disposed opposite the photoconductive drum 11.
At the development position, the toner particles T contained in the developer G adhere to the electrostatic latent image formed on the outer circumferential surface of the photoconductive drum 11. For example, an electrostatic latent image potential, that is, an exposure potential, created by a laser beam L irradiating the photoconductive drum 11 and a development bias applied to the development roller 13a produce a potential difference, that is, a development potential, that creates an electric field. The electric field causes the toner particles T to adhere to the electrostatic latent image formed on the photoconductive drum 11, thus visualizing the electrostatic latent image into a toner image.
The toner particles T adhered to the photoconductive drum 11 during the development process are mostly primarily transferred onto the intermediate transfer belt 17. Conversely, residual toner particles T failed to be transferred onto the intermediate transfer belt 17 and therefore remaining on the photoconductive drum 11 are removed and collected by the cleaning blade 14a and the cleaning roller 14b into the cleaner 14. Thereafter, the outer circumferential surface of the photoconductive drum 11 passes through the lubricant supplier 15 and the discharger successively. Thus, a series of image forming processes performed on the photoconductive drum 11 is completed.
A detailed description is now given of a construction of the toner supplier 30.
The toner supplier 30 located inside the image forming apparatus 1 depicted in
As the toner particles T contained in the development device 13 are consumed, fresh toner particles T contained in the toner bottle 31 are supplied into the development device 13 through the toner inlet as appropriate. Consumption of the toner particles T contained in the development device 13 is detected by a reflective photo sensor disposed opposite the photoconductive drum 11 or a magnetic sensor situated below the secondary conveyance screw 13c of the development device 13 directly or indirectly.
A description is provided of a configuration and an operation of the lubricant supplier 15 that supplies and applies the lubricant to the photoconductive drum 11.
As described above with reference to
With reference to
The ball bearings 15m absorb vibration created by the lubricant application roller 15a as it rotates and slides over the solid lubricant 15b and the photoconductive drum 11. As shown in
According to this example embodiment, the ball bearing 15m is used as a rolling-element bearing that supports the lubricant application roller 15a. Alternatively, a roller bearing, a needle bearing, a tapered roller bearing, a spherical roller bearing, and the like may be used as a rolling-element bearing that supports the lubricant application roller 15a. The ball bearing 15m has an interior structure in which the balls 15m3 contact the inner race 15m1 and the outer race 15m2 in a decreased area, facilitating interruption of vibration transmission from the inner race 15m1 to the outer race 15m2.
With reference to
As shown in
As shown in
As shown in
As shown in
The above describes the construction of the lubricant supplier 15 that serves as an image carrier surface treatment device. Additionally, the cleaner 14 depicted in
As shown in
As shown in
According to the above-described example embodiments, the image forming apparatus 1 is installed with the development device 13 that employs a two-component development method using a two-component developer containing toner particles and carrier particles. Alternatively, the image forming apparatus 1 may be installed with a development device that employs a one-component development method using a one-component developer containing toner particles.
Further, according to the above-described example embodiments, the lubricant supplier 15 disposed opposite the photoconductive drum 11 supplies a lubricant to the photoconductive drum 11 serving as an image carrier. Alternatively, the lubricant supplier 15 may be disposed opposite a photoconductive belt serving as an image carrier to supply a lubricant to the photoconductive belt. Additionally, the lubricant supplier 15 may be disposed opposite the intermediate transfer belt 17 depicted in
As shown in
According to the example embodiments described above, the lubricant application roller 15a and the cleaning roller 14b are positioned inside the lubricant supplier 15 and the cleaner 14 through the ball bearings 15m and 14m, respectively. Alternatively, the lubricant application roller 15a may be positioned inside the lubricant supplier 15 through the ball bearings 15m and the cleaning roller 14b may not be positioned inside the cleaner 14 through the ball bearings 14m. For example, as the lubricant application roller 15a slides over the solid lubricant 15b and the photoconductive drum 11, the lubricant application roller 15a is subject to substantial vibration. To address this circumstance, the ball bearings 15m anchored to the frame 15g of the lubricant supplier 15 supports the lubricant application roller 15a to reduce transmission of vibration from the lubricant application roller 15a to the photoconductive drum 11, thus suppressing formation of a faulty toner image that may be caused by vibration of the photoconductive drum 11.
According to the example embodiments described above, the ball bearings 15m and 14m support the lubricant application roller 15a and the cleaning roller 14b, respectively. Alternatively, since the charging roller 12a depicted in
With reference to
An image carrier surface treatment device (e.g., the lubricant supplier 15 and the cleaner 14) is disposed opposite an image carrier (e.g., the photoconductive drum 11) rotatable in a first rotation direction (e.g., the rotation direction R1) and carrying a toner image. The image carrier surface treatment device includes a roller (e.g., the lubricant application roller 15a and the cleaning roller 14b) in contact with the outer circumferential surface of the image carrier and rotatable in a second rotation direction (e.g., the rotation directions R4 and R3) to slide over the image carrier and a rolling-element bearing (e.g., the ball bearings 15m and 14m) fitted onto a shaft (e.g., the shafts 15a1 and 14b1) projecting from each lateral end of the roller in the axial direction thereof. The roller is positioned inside the image carrier surface treatment device through each rolling-element bearing.
Accordingly, the rolling-element bearings supporting the roller reduce transmission of vibration from the roller to the image carrier, suppressing formation of a faulty toner image such as a streaky toner image that may appear due to vibration from the roller. The image carrier surface treatment device is installable in a process cartridge (e.g., the process cartridges 10Y, 10M, 10C, and 10K) that is detachably attachable to the image forming apparatus 1.
The present invention has been described above with reference to specific example embodiments. Note that the present invention is not limited to the details of the embodiments described above, but various modifications and enhancements are possible without departing from the spirit and scope of the invention. It is therefore to be understood that the present invention may be practiced otherwise than as specifically described herein. For example, elements and/or features of different illustrative example embodiments may be combined with each other and/or substituted for each other within the scope of the present invention.
Number | Date | Country | Kind |
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2012-151891 | Jul 2012 | JP | national |