JP4722473B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, and a facsimile machine, which has an image carrier, a charging device, an electrostatic latent image forming device, a developing device, and a transfer device, and omits the function of a cleaning device. The present invention relates to an image forming apparatus capable of uniformly polishing an image carrier and discharging a polished product.

  In recent years, image forming apparatuses have been required to have high image quality, space saving, energy saving, cost reduction, noise reduction, environmental safety, etc. Among them, the cleaning apparatus is an image carrier for image formation. It occupies an important position as a process that enables continuous and repeated use. The cleaning device consists of a removal device for removing toner and other deposits remaining on the image carrier in the transfer process, a device for collecting these in a tank, and a device for removing the residual potential of the image carrier. Has been.

  Although such a cleaning device has been omitted and improvements have been made to realize space saving, if there is no cleaning device, the image carrier surface is not rubbed and the residue on the image carrier surface is sufficiently removed. In other words, the residue is accumulated, which causes a filming layer due to residual toner. Further, the image carrier uses a discharge generated at a high voltage. However, since the image carrier itself deteriorates when discharged, there arises a problem that the electrostatic latent image is diffused and the image is blurred. Further, even when a lubricant is applied to the surface of the image carrier to improve the transferability of the toner, the lubricant oxidized by the discharge accumulates on the surface of the image carrier and causes problems such as deterioration of image quality. Therefore, although there are several functions of the cleaning device, it is known that the polishing function for removing the residue on the surface of the image carrier is a function that cannot be omitted. Is also required.

The conventional image forming apparatus, those and which has an abrasive sheet for removing a residue on the surface of the image bearing member (for example, Patent Document 1 see), it shall have a polishing means to a developing device Oh Ru (for example, Patent Document 2 see). Also, special rubbing means and the rolling friction with the residue removal, the developing device in which collection and special rubbing means when the remaining Tomebutsu surface of the image bearing member passes through the rubbing portion by rubbing position the by also functions scraping device to the transfer device not provided and some removing residues (e.g., Patent Document 3 see).

Japanese Patent Laid-Open No. 11-073076 JP 2002-214870 A Japanese Patent Application Laid-Open No. 2002-082573

  Improvements to remove the residue on the surface of the image carrier have been promoted as described above. However, when a cleaning device is provided, it becomes difficult to realize space saving and cost reduction. In addition, when a polishing device or a rubbing device in which the function of the cleaning device is omitted is provided, the surface of the image bearing member is moderately polished without excessively scraping, and uniform polishing without causing unevenness of the polishing, maintenance of its polishing ability, and polished polishing Processing of things etc. becomes a problem.

  Therefore, the present invention provides a polishing device that omits the function of the cleaning device to facilitate uniform polishing of the surface of the image bearing member and maintenance of the polishing capability, and enables the developing device to collect the polished material, It is an object of the present invention to reduce the size and cost of an image forming apparatus.

In order to solve the above problems, the present invention has the following features.
The image forming apparatus of the present invention comprises an image carrier, a charging device that is disposed in contact with or close to the image carrier, and charges the surface of the image carrier, and the surface of the image carrier is exposed to static A writing device that writes an electrostatic latent image, a developing device that visualizes the latent image formed on the surface of the image carrier with toner, and a transfer device that transfers the visible image on the surface of the image carrier to transfer paper; The image forming apparatus is provided with a polishing device that contacts the image carrier in a planar shape with non-uniform pressure, and the polishing device includes a uniform polishing sheet and a pressing member protrusion, and the pressurizing member. a pressure member for pressurizing unevenly pressurized from a more back side of the abrasive sheet to the projections made, the polishing apparatus, when bisected pressure distribution in contact in a non-uniform pressure on the high part and a low part, the image The low pressure part of the polishing apparatus was moved from the upstream side to the downstream side in the direction of movement of the carrier. When Tsu, polished generated by polishing of the image bearing member is in contact with the image bearing member at a pressure distribution that is discharged to the downstream side of the polishing apparatus through the low pressure section, said image by said polishing device The polishing product generated by polishing the carrier is collected by the developing device.
In order to cut the image bearing member smoothly, it is preferable to polish the image carrier over a large area. However, if surface polishing is performed with uniform contact, the polishing powder accumulates on the polishing surface, causing deterioration in polishing properties and image quality deterioration. I have to. In addition, it is not necessary to provide a separate device for recovering the polished material generated by polishing, so that space can be saved.
When the pressure distribution in contact with the non-uniform pressure is divided into a high part and a low part, the polishing apparatus traces the low pressure part of the polishing apparatus from the upstream side to the downstream side in the image carrier moving direction. In addition, it is possible to prevent excessive stress from being applied to the image carrier by contacting the image carrier with a pressure distribution in which a residue such as a polished material passes through a low-pressure portion and is discharged to the downstream side of the polishing apparatus. Polishing is performed so that the residue can be moved and discharged.
In the image forming apparatus of the present invention, the polishing sheet can be moved in the longitudinal direction with respect to the pressure member in a band shape, and both ends of the band are connected in a loop shape or supplied from one side. And it is characterized by having a structure of winding on one side. By dividing the pressure member and the polishing sheet, the polishing surface can be easily and automatically refreshed to maintain the polishing ability.
The image forming apparatus of the present invention further includes a lubricant applying device, and the lubricant applying device applies the lubricant to the image carrier in a timely manner. When the lubricant is applied, the surface energy of the image carrier is lowered, so that the adhesion between the toner and the image carrier is weakened, and the transferability of the toner is improved.

  By means for solving the above-mentioned problems, the present invention provides a polishing apparatus in which the function of the cleaning apparatus is omitted, and a space is saved by designing an image forming apparatus that collects residues such as polished polished articles with a developing apparatus. And cost reduction. In addition, the pressure member and the polishing sheet are divided into a polishing device that polishes in a planar shape with non-uniform pressure, so that polishing is performed so as not to apply excessive stress to the image carrier, and the residue is moved and discharged. The polishing surface can be easily and automatically refreshed, and the polishing ability can be maintained.

The best mode for carrying out the present invention will be described below with reference to FIGS. However, these are merely embodiments, and do not limit the scope of the claims of the present invention.
FIG. 1 is a side view of the image forming apparatus of the present invention. The cleaning device is omitted, and the lubricant application device 13 and the polishing device 30 are provided. The charging roller 2 1 to the periphery of the image carrier 1, write can narrowing device 22, a developing device 2, the transfer device 18 is disposed. Although the charging device is exemplified by the non-contact type charging roller 21, it may be a corona charging device such as scorotron or corotron, or a contact type charging roller, and a DC voltage may be superimposed on the applied voltage. Although the developing device 2 is a two-component developing device as an example, one-component / two-component, contact / non-contact is not an essential condition. The transfer device 18 is exemplified by the transfer belt 10, but may be roller transfer or corona transfer, or may be directly transferred to a transfer sheet or transferred to an intermediate transfer member.

The lubricant application device 13 can be rotated / separated around the applicator release rotation center 17 and can be separated / attached at an appropriate time by a driving device (not shown). In the lubricant application device 13, a lubricant 14, a lubricant application roller 15, and a lubricant leveling blade 16 are incorporated.
As the lubricant 14, a block of zinc stearate is often used. This is because the lubrication effect is high and the molding is easy. In addition to this, metal soaps, waxes, and fluorine-containing resins also show similar effects. The lubricant 14 is made into a block shape and pressed against the lubricant application roller 15. As a pressing method, there are a method of using gravity by attaching a weight, a method of applying pressure by attaching a spring, and a method of controlling the pressurizing force and pressurizing timing with a solenoid or the like.
Since the lubricant application roller 15 has a function of rubbing the lubricant 14 on the image carrier, it needs flexibility to maintain an appropriate surface roughness and uniformity of contact pressure. Siri co Ngomu, urethane rubber, may be a roller of other synthetic rubbers, relatively hard resin coated on its surface, such as polyamide, polyethylene, PET, having a high durability can be obtained when using a resin or the like containing fluorine. In addition to this, foamed rubber and roller-shaped brushes may be used as the application roller, but since these have low surface smoothness, the consumption of the lubricant tends to increase. The lubricant application roller 15 is rotationally driven by a rotational drive device (not shown). Since the rotation shaft of the lubricant application roller 15 is fixed to the lubricant application device 13 in a rotatable manner, the lubricant application device 13 is released in a timely manner. Depending on the configuration, the lubricant is continuously scraped, so that it is preferable to stop in synchronization with the release of the lubricant application device 13. In this example, the rotation direction at the time of rotation is the same as that of the image carrier 1 at the contact portion. In addition to this, it is possible to reverse the rotation direction by reversing the arrangement of the surrounding members.
The lubricant leveling blade 16 is a member that blocks excess lubricant 14, makes the lubricant 14 applied to the image carrier 1 uniform, fixes it, and prevents it from moving outside a predetermined location. For reasons of contact uniformity and wear resistance, blades of urethane rubber and other synthetic rubbers are preferred, but resin blades such as PET and polyamide are also effective.

  The polishing device 30 was disposed downstream of the charging roller 21. Since the polishing apparatus 30 emits polishing powder, this position is preferable in order to prevent contamination of the charging roller 21, but it may be arranged elsewhere because of layout.

FIG. 2 shows the configuration of the polishing apparatus 30. The pressure member 31 has a pressure member protrusion 32 that presses unevenly from the back surface of the polishing sheet 33. Polishing sheet 33 is a sheet-like substrate surface to abrasive sandpaper-like bonded sheet, or tree fats abrasive is kneaded, a sheet of rubber, obtained by substantially uniform surface is there. The base material is suitably cloth, resin film, rubber or the like. As the abrasive, materials such as diamond, corundum, emery, meteorite, silicon carbide, boron nitride, iron oxide, chromium oxide, cerium oxide, and silicon oxide are generally used. The pressing portion of the polishing sheet pressed from the back by the pressing member polishes the surface of the image carrier 1. When the pressure distribution in contact with the non-uniform pressure is divided into a high part and a low part, when the low pressure part of the polishing apparatus 30 is traced from the upstream side to the downstream side in the moving direction of the image carrier 1, The polished object passes through the low pressure portion and is discharged to the downstream side of the polishing apparatus 30. The discharged polished material and the like are collected by the developing device 2. The collected abrasive or the like is accumulated in the apparatus, or is developed on the image carrier 1 together with toner, transferred to transfer paper, and discharged outside the apparatus. In order to make the toner behave in the same manner as the toner, it is preferable to select a material so that the triboelectric charging characteristics of the abrasive of the image carrier 1 and the carrier in the developer have the same relationship as that of the toner.

  FIG. 3 shows an example of the pressure member protrusion 32 that is required to swing. By swinging at a pitch equal to or greater than the gap between the protrusions, the entire width of the image carrier 1 can be uniformly polished.

  FIG. 4 shows an example of the pressing member protrusion 32 where swinging is not essential. Since the protrusions arranged in an island shape are arranged so as to fill the gaps in the front row, no unpolished portions are generated. As the image carrier 1 travels, the polished material or the like proceeds obliquely through the low pressure region and is discharged from the polishing region. In this case, the entire width of the image carrier 1 can be uniformly polished without swinging. However, by swinging, the polished object or the like can be moved more easily and discharged easily.

FIG. 5 shows an example in which a polishing sheet 33 made in an endless belt shape is circulated by two polishing sheet feed rollers 34 so as to be movable with respect to the pressure member. By automatically supplying a new polishing sheet surface, it is possible to automate and facilitate replacement of the abrasive sheet 33 which is a consumable, and maintain the polishing ability. The polishing sheet 33 has a belt-like shape and is movable in the longitudinal direction with respect to the pressure member 31. Both ends of the belt are connected in a loop shape, or are supplied from one side and wound on one side. . Further, by installing the polishing sheet 33 in the form of an endless belt, the frequency of replacement of the polishing sheet 33 can be reduced, and the life of the polishing apparatus 30 can be extended.
The life can be further extended by providing a polishing sheet cleaning device (not shown) outside the contact area with the image carrier 1. The cleaning device is preferably a fixed brush, a rotating brush, air blowing, sucking, or sticking with an adhesive roller.

  6 and 7 show an example of the pressing member protrusion 32 in which abrasives and the like are accumulated in the low-pressure portion, and rocking is not essential.

Although FIGS. 1 to 7 show examples using the polishing sheet 33, the protrusions themselves of the pressure member may be abrasive. The same effect can be obtained if at least the protrusion has a surface roughness made of a hard material, or has a surface with an abrasive.

1 is a side view of an image forming apparatus of the present invention. 1 shows a configuration of a polishing apparatus. It is an example of a pressurizing member protrusion that is required to swing. It is an example of the pressurizing member protrusion which is not essential to swing. This is an example in which a polishing sheet made in an endless belt shape is circulated by two polishing sheet feed rollers so as to be movably attached to a pressure member. This is an example of a pressing member protrusion in which abrasives or the like are accumulated in the low-pressure part and rocking is not essential. This is an example of a pressing member protrusion in which abrasives or the like are accumulated in the low-pressure part and rocking is not essential.

DESCRIPTION OF SYMBOLS 1 Image carrier 2 Developing apparatus 3 Developing roller 4 Developing sleeve 5 Magnet 6 Doctor blade 7 Developer conveying screw A
8 Developer transport screw B
9 Developer stencil plate 10 Transfer belt 11 Transfer belt stretching roller 12 Transfer belt drive roller 13 Lubricant coating device 14 Lubricant 15 Lubricant coating roller 16 Lubricant leveling blade 17 Coating device release rotation center 18 Transfer device 21 Charging roller 22 Writing device 30 Polishing device 31 Pressure member 32 Pressure member protrusion 33 Polishing sheet 34 Polishing sheet feed roller

Claims (3)

An image carrier;
A charging device disposed in contact with or in proximity to the image carrier to charge the surface of the image carrier;
A writing device for exposing the surface of the image carrier and writing an electrostatic latent image;
A developing device that visualizes the latent image formed on the surface of the image carrier with toner;
In an image forming apparatus having a transfer device that transfers a visible image on the surface of the image carrier to transfer paper,
A polishing device is provided that contacts the image carrier in a planar and non-uniform pressure,
The polishing apparatus includes a uniform abrasive sheet, a pressure member for pressurizing unevenly pressurized more from the back of the abrasive sheet to the pressurizing protrusion has a pressure member projections made,
When the pressure distribution in contact with the non-uniform pressure is divided into a high part and a low part, the polishing apparatus traces the low pressure part of the polishing apparatus from the upstream side to the downstream side in the image carrier moving direction. In addition, the polishing object generated by polishing the image carrier is in contact with the image carrier with a pressure distribution that passes through a low pressure portion and is discharged to the downstream side of the polishing apparatus.
An image forming apparatus, wherein a polishing product generated by polishing the image carrier by the polishing apparatus is collected by the developing device. The polishing sheet has a band shape and is movable in the longitudinal direction with respect to the pressure member, and both ends of the band are connected in a loop shape, or supplied from one side and wound up on one side. The image forming apparatus according to claim 1. The image forming apparatus according to claim 1, wherein the image forming apparatus further includes a lubricant applying device, and the lubricant applying device applies a lubricant to the image carrier in a timely manner .

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