JP5471171B2 - Cleaning device, process cartridge, image forming apparatus, and image forming method - Google Patents

Description

  The present invention relates to a cleaning blade for contacting and cleaning an image carrier provided in an image forming apparatus such as a copying machine, a facsimile machine, a printer, and the like, and an image carrier protective agent for protecting the image carrier to the image carrier. A cleaning device comprising: an image carrier protecting agent supply means to be supplied; and an image carrier protecting agent uniformizing means for homogenizing the image carrier protecting agent supplied to the image carrier on the surface of the image carrier. The present invention relates to a process cartridge including the above, an image forming apparatus including these, and an image forming method using them.

  In an image forming apparatus such as a copying machine, a facsimile machine, or a printer, an image forming apparatus provided with an image carrier such as a photoconductor composed of a photosensitive layer containing a photoconductive substance or the like. On the other hand, image formation is performed by performing a charging process, an exposure process, a development process, a transfer process, a fixing process, and the like.

  In the charging step, the image carrier is uniformly charged. In the exposure process, a latent image pattern is formed by laser light or the like on the image carrier whose surface is charged in the charging process. In the development step, the charged toner particles are attached to the surface of the image carrier corresponding to the latent image pattern to form a visible image. In the transfer step, the visible image is transferred from the image carrier to a recording medium such as paper. In the fixing step, the visible image transferred to the recording medium is fixed to the recording medium by heat, pressure, other solvent gas, or the like. By these steps, an output image is formed on the recording medium.

  The development method in the development process is roughly classified into a two-component development method and a one-component development method depending on a method of charging toner particles. The two-component development method uses tribocharging by stirring and mixing toner particles and carrier particles. In the one-component development system, electrification is applied to toner particles without using carrier particles. The one-component development method is classified into a magnetic one-component development method and a non-magnetic one-component development method depending on whether or not the developer carrier that carries toner particles uses a magnetic force to hold the toner particles.

  Among these development methods, in copying machines that require high speed and development reproducibility, and multi-function machines based on these, such as charging stability of toner particles, start-up property, long-term stability of image quality, etc. The two-component development method is often used because of demands, and the one-component development method is often adopted for small printers, facsimiles, and the like that demand large space saving and low cost.

  Nowadays, with any development method, colorization of output images has progressed, and there has been a demand for higher definition, and there has been a demand for higher image quality and higher image quality with high resolution and gradation. Since it is becoming stronger and stronger, the average particle diameter of the toner particles is reduced regardless of the development method, and the shape of the toner particles is made to be rounder with fewer angular portions. The toner having a small particle size and a spherical shape as described above is suitable for obtaining a high-definition image because faithful transfer is performed in the transfer process.

  Such toner particles having a small average particle diameter and a rounder shape can be produced using a polymerization method. The polymerization method is excellent in improving image quality as well as in reducing production energy, and has an excellent feature that the particle diameters of toner particles are uniform.

  The toner component that has not been transferred to the transfer medium remains on the image carrier after the transfer process. If the charging process is performed again in this state, uniform charging of the image carrier is often hindered. . Therefore, in general, in addition to the above-described steps, after the transfer step and before the charging step, residual toner that is a transfer residual toner that is a toner component remaining on the image carrier and other foreign matters such as paper dust are cleaned. An edge portion of a cleaning member such as a blade is removed by a cleaning process in which it is cleaned by being pressed against the image carrier, and the charging process is performed after the surface of the image carrier is sufficiently clean (for example, [See Patent Document 1] to [Patent Document 6]).

However, as described above, the average particle diameter of the toner particles is reduced, and the shape of the toner particles is rounder. In recent years, for example, the toner is easy to roll due to spheroidization. Therefore, the toner particles are difficult to be dammed up, and the toner enters between the image carrier and the cleaning member, so that it is difficult to remove the toner component by the cleaning process, and cleaning failure is likely to occur. If residual toner remains on the image bearing member due to poor cleaning, this may stain charging members such as a charging roller that performs the charging process, which may cause abnormal images such as black spots and ground fog on the image. .
Therefore, measures such as increasing the pressure for pressing the cleaning member against the surface of the image carrier are taken.

  The surface of the image carrier is subjected to various physical stresses in each of the above-described steps, and its state changes as the usage time becomes longer. In particular, it is known that stress due to friction in the cleaning process wears the image carrier and causes scratches. Therefore, in order to reduce the frictional force between the image carrier and the cleaning member, various lubricants and lubricant components have been supplied as image carrier protection agents, and a film is formed on the surface of the image carrier. Many proposals have been made on the technology for performing (see, for example, [Patent Document 1] to [Patent Document 4]).

  As such a technique, for example, a technique in which a lubricant is added to toner (see, for example, [Patent Document 1]), a lubricant is supplied to the image carrier, and a lubricant supply position in the rotation direction of the image carrier. A technique for performing a cleaning process with a cleaning blade on the downstream side (see, for example, [Patent Document 2]), supplying a lubricant to the image carrier, and upstream from a lubricant supply position in the rotation direction of the image carrier. An image carrier that performs a cleaning process with a cleaning blade on the side and uniformizes the lubricant supplied to the image carrier downstream of the supply position of the lubricant in the rotation direction of the image carrier on the surface of the image carrier A technique (for example, see [Patent Document 3] and [Patent Document 4]) including a protective agent uniformizing means has been proposed.

  However, the technique in which a lubricant is added to the toner has a problem that the distribution of the lubricant on the image carrier becomes non-uniform depending on the state of the image to be developed, and the occurrence of an abnormal image cannot be prevented. Further, in the technique of supplying a lubricant to the image carrier and performing a cleaning process by a cleaning blade downstream of the lubricant supply position in the rotation direction of the image carrier, the above-mentioned technique is based on the technique in which the lubricant is added to the toner. However, in this technique, since the lubricant is supplied to the image carrier before cleaning, it is difficult to supply the lubricant to the image carrier depending on the amount and distribution of residual toner on the image carrier. Or the unevenness of the lubricant on the image carrier occurs, and the lubricant on the image carrier is removed together with the residual toner by the cleaning blade, resulting in a large loss of lubricant. is there.

  In this regard, in the above-described technique equipped with the image carrier protective agent uniformizing means, the lubricant is supplied to the image carrier after cleaning, so that the lubricant is supplied to the image carrier and the rotation direction of the image carrier The above-described problems due to the technique of performing the cleaning process with the cleaning blade downstream of the supply position of the lubricant can be avoided.

  However, in the above-described technique provided with the image carrier protective agent uniformizing means, if the lubricant is not supplied sufficiently and stably to the image carrier, for example, a blade that contacts the image carrier is used as a member for performing such homogenization. In the configuration provided, abnormal noise due to chatter vibration or reversal of the blade, abnormal wear or crack of the blade, etc. may occur, so that the uniformization of the lubricant by the image carrier protective agent uniformizing means may be insufficient. There's a problem. Further, fatty acid metal salts such as zinc stearate known as lubricants are known to be degraded and deteriorated due to electrical stress received in the charging process and changed to high viscosity substances. When it occurs, such abnormal noise, abnormal wear, and cracks are likely to occur. Such abnormal noise, abnormal wear, and cracks have a significant effect on lowering the uniform performance of the lubricant by the image carrier protective agent uniformizing means.

  In this regard, the inventors have found that if there is residual toner at the position where the image carrier protective agent uniformizing means homogenizes the lubricant on the image carrier, chatter vibration and reversal of the blade are prevented or suppressed. Thus, it has been found that such abnormal noise, abnormal wear, and cracks are prevented or suppressed, and that the uniformization of the lubricant by the image carrier protective agent uniformizing means is performed well over time.

  The present invention relates to a cleaning blade for contacting and cleaning an image carrier provided in an image forming apparatus such as a copying machine, a facsimile machine, a printer, and the like, and an image carrier protective agent for protecting the image carrier to the image carrier. The image carrier protecting agent supplying means and the image carrier protecting agent uniformizing means for homogenizing the image carrier protecting agent supplied to the image carrier on the surface of the image carrier. A cleaning device that is provided in order from the upstream side so that the transfer residual toner exists at a position where the image carrier protective agent uniformizing means uniformizes the lubricant on the image carrier, a process cartridge provided with the cleaning device, and the like Another object of the present invention is to provide such an image forming apparatus and an image forming method using them.

In order to achieve the above object, a first aspect of the present invention is directed to a cleaning blade that has a ridge line portion that extends in the longitudinal direction of the image carrier and is in contact with the image carrier, and that cleans the image carrier; Protective agent supply means for supplying the image carrier with an image carrier protective agent for protecting the image carrier downstream of the position where the cleaning blade is in contact with the image carrier in the moving direction of the carrier; On the surface of the image carrier, the image carrier protective agent supplied to the image carrier downstream of the position where the image carrier protective agent is supplied to the image carrier by the protective agent supply means in the moving direction. An image carrier protective agent homogenizing means for homogenizing, and one end portion is disposed in contact with the image carrier so as to shield between the cleaning blade and the protective agent supply means, Opposite to the one end Has an end portion side is fixed to the case, the partition walls forming a reservoir for collecting the foreign substances scattered from the protective material supply means, and a discharge screw for discharging the foreign substance from the reservoir, The ridge line portion of the cleaning blade is in a cleaning device having an obtuse angle on a cross section by a plane orthogonal to the longitudinal direction.

According to a second aspect of the invention, the cleaning device according to claim 1, wherein the obtuse angle of the cleaning blade and less than 140 degrees 95 degrees.

According to a third aspect of the present invention, in the cleaning device according to the first or second aspect , the image carrier protective agent uniformizing means extends in the longitudinal direction of the image carrier and is in contact with the image carrier. It has an image carrier protective agent homogenizing blade having the following.

According to a fourth aspect of the present invention, in the cleaning device according to the third aspect , the ridge line portion of the image carrier protecting agent uniformizing blade has an obtuse angle on a cross section by a plane orthogonal to the longitudinal direction. Features.

According to a fifth aspect of the present invention, in the cleaning device according to the fourth aspect , the obtuse angle of the image carrier protective agent uniformizing blade is 95 degrees or more and less than 140 degrees.

According to a sixth aspect of the present invention, in the cleaning device according to the third aspect , the angle on the cross section of the ridge line portion of the image carrier protective agent uniformizing blade by a plane orthogonal to the longitudinal direction is approximately 90 degrees. It is characterized by that.

According to a seventh aspect of the present invention, in the cleaning device according to any one of the third to sixth aspects, the image carrier protective agent uniformizing blade is in counter contact with the image carrier. To do.

According to an eighth aspect of the present invention, in the cleaning apparatus according to any one of the third to seventh aspects, the image carrier protective agent uniformizing means is a blade that fixes and supports the image carrier protective agent uniform blade. It has a fixed support means.

According to a ninth aspect of the present invention, in the cleaning apparatus according to any one of the third to seventh aspects, the image carrier protective agent uniformizing means supports the image carrier protective agent uniformizing blade and supports the same image. A blade constant load support means for bringing the carrier protective agent uniformizing blade into contact with the image carrier with a constant load is provided.

A tenth aspect of the present invention resides in a process cartridge having the cleaning device according to any one of the first to ninth aspects.

An eleventh aspect of the present invention is an image forming apparatus having the cleaning apparatus according to any one of the first to ninth aspects or the process cartridge according to the tenth aspect .

According to a twelfth aspect of the present invention, in the image forming apparatus according to the eleventh aspect , a toner having a circularity of 0.92 or more is used.

According to a thirteenth aspect of the present invention, in the image forming apparatus according to the eleventh or twelfth aspect , the toner having a shape factor SF-1 in the range of 100 to 180 and a shape factor SF-2 in the range of 100 to 180. It is characterized by using.

According to a fourteenth aspect of the present invention, in the image forming apparatus according to any one of the fourth to seventh aspects, the volume average particle diameter (Dv) is in the range of 3 μm to 8 μm, and the volume average particle diameter (Dv ) And the number average particle size (Dn) (Dv / Dn), a toner having a dispersity defined by 1.05 or more and 1.40 or less is used.

According to a fifteenth aspect of the present invention, in the image forming apparatus according to any one of the eleventh to fourteenth aspects, the ratio (r2 / r1) between the length (r2) of the minor axis and the length (r1) of the major axis. ) Is in the range of 0.5 to 1.0, and the ratio (r3 / r2) of the thickness (r3) to the length (r2) of the minor axis is in the range of 0.7 to 1.0. And a toner satisfying the relationship of the length of the major axis (r1) ≧ the length of the minor axis (r2) ≧ the thickness (r3) is used.

According to a sixteenth aspect of the present invention, in the image forming apparatus according to any one of the twelfth to fifteenth aspects, the toner includes a polyester polymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent. A toner composition containing a mold agent is formed by crosslinking and / or stretching reaction in the presence of resin fine particles in an aqueous medium.

The invention described in claim 17 is the cleaning device according to any one of claims 1 to 9 , the process cartridge according to claim 10 , or the image according to any one of claims 11 to 16. An image forming method for forming an image using a forming apparatus.

The present invention includes a cleaning blade that extends in the longitudinal direction of the image carrier and has a ridge line portion that is in contact with the image carrier, and that cleans the image carrier, and the cleaning blade in the moving direction of the image carrier. A protective agent supply means for supplying the image carrier with an image carrier protective agent for protecting the image carrier downstream from a position in contact with the carrier; and the protective agent supply means in the moving direction by the protective agent supply means. Uniform image carrier protective agent for uniformizing the image carrier protective agent supplied to the image carrier downstream from the position where the image carrier protective agent is supplied to the image carrier. And an end opposite to the one end so as to shield between the image forming means, the cleaning blade and the protective agent supplying means. parts is fixed to the case, the It has a partition wall for forming a reservoir for collecting the foreign substances scattered from Mamoruzai supply means, and a discharge screw for discharging the foreign substance from the reservoir, the ridge portions of the cleaning blade, the longitudinal Since the residual toner passes through between the ridge line portion of the cleaning blade and the image carrier, the image carrier protective agent uniformizing means becomes a lubricant. The residual toner is present at a position where the toner is uniformized on the image carrier, and the lubricant is uniformized over time by the image carrier protective agent uniformizing means, which can contribute to good image formation. An apparatus can be provided.

  If the obtuse angle of the cleaning blade is 95 degrees or more and less than 140 degrees, the residual toner is appropriately slipped between the ridge line portion of the cleaning blade and the image carrier, so that the image carrier protective agent is uniform. Residual toner exists at the position where the image forming means makes the lubricant uniform on the image carrier, and the uniformization of the lubricant by the image carrier protective agent uniformizing means is performed well over time, contributing to good image formation It is possible to provide a cleaning device that can be used.

  If the image carrier protective agent homogenizing means has an image carrier protective agent homogenizing blade extending in the longitudinal direction of the image carrier and having a ridge portion in contact with the image carrier, a cleaning blade The residual toner slips between the edge of the image carrier and the image carrier, so that the residual toner exists at a position where the image carrier protective agent uniformizing blade homogenizes the lubricant on the image carrier. The chatter vibration and reversal of the agent uniformizing blade are prevented or suppressed, and abnormal noise, abnormal wear, and cracks caused by these are prevented or suppressed, and the homogenization of the lubricant by the image carrier protective agent uniforming blade is performed well over time. Therefore, it is possible to provide a cleaning device that can contribute to good image formation.

  The ridge line portion of the image carrier protective agent uniformizing blade is left between the ridge line portion of the cleaning blade and the image carrier, assuming that the angle on the cross section of the plane perpendicular to the longitudinal direction is an obtuse angle. When the toner slips through, the residual toner is present at a position where the image carrier protective agent uniformizing blade homogenizes the lubricant on the image carrier, and the obtuse angle causes chatter vibration of the image carrier protective agent uniforming blade. Reversal is highly prevented or suppressed, abnormal noise, abnormal wear and cracks due to these are highly prevented or suppressed, and the uniformization of the lubricant by the image carrier protective agent uniformizing blade is performed better over time, and more A cleaning device that can contribute to good image formation can be provided.

  Assuming that the obtuse angle of the image carrier protective agent uniformizing blade is 95 degrees or more and less than 140 degrees, residual toner slips between the ridge line portion of the cleaning blade and the image carrier, so that the image carrier Residual toner is present at the position where the body protective agent uniformizing blade makes the lubricant uniform on the image carrier, and the moderate obtuse angle prevents the chatter vibration and reversal of the image carrier uniformizing blade more highly. Abnormal noise, abnormal wear, and cracks due to these are prevented or suppressed to a higher degree, and the uniformization of the lubricant by the image carrier protective agent uniformizing blade is better performed over time, and better image formation A cleaning device that can contribute to the above can be provided.

  If the ridge line portion of the image carrier protective agent uniformizing blade has a cross-sectional angle of approximately 90 degrees by a plane orthogonal to the longitudinal direction, the ridge line portion between the cleaning blade and the image carrier is assumed to be approximately 90 degrees. As the residual toner slips through, the residual toner exists at a position where the image carrier protective agent uniformizing blade homogenizes the lubricant on the image carrier. By preventing or suppressing abnormal noise, abnormal wear, and cracks due to these, the angle is approximately 90 degrees. In addition, the uniforming of the lubricant by the image carrier protective agent uniformizing blade is achieved. It is possible to provide a cleaning device that can perform better over time and contribute to better image formation.

  If the image carrier protective agent uniformizing blade is in counter contact with the image carrier, the residual toner slips between the edge of the cleaning blade and the image carrier, thereby protecting the image carrier. Residual toner exists at the position where the agent homogenizing blade homogenizes the lubricant on the image carrier, and chatter vibration and reversal of the image carrier protective agent homogenizing blade are prevented or suppressed, resulting in abnormal noise and abnormal wear In addition to this, cracks are prevented or suppressed, and in addition to this, the counter contact makes uniforming of the lubricant by the image carrier protective agent uniformizing blade better over time, contributing to better image formation. It is possible to provide a cleaning device capable of

  If the image carrier protective agent uniformizing means has blade fixing support means for fixing and supporting the image carrier protective agent uniformizing blade, residual toner is provided between the edge of the cleaning blade and the image carrier. The residual toner is present at the position where the image carrier protective agent uniformizing blade homogenizes the lubricant on the image carrier by slipping through the image carrier protective agent uniforming blade, preventing or suppressing chatter vibration and reversal of the image carrier protective agent uniforming blade. In addition, abnormal noise, abnormal wear, and cracks due to these are prevented or suppressed, and in addition to this, the contact angle of the image carrier protective agent uniformizing blade to the image carrier is kept constant by such fixed support, Provided is a cleaning device in which the homogenization of the lubricant by the image carrier protective agent uniformizing blade is performed better over time and can contribute to better image formation. It can be.

  The image carrier protecting agent uniformizing means is a blade constant load supporting means for supporting the image carrier protecting agent uniformizing blade and bringing the image carrier protecting agent uniformizing blade into contact with the image carrier with a constant load. If the residual toner passes between the ridge line portion of the cleaning blade and the image carrier, the image carrier protective agent uniformizing blade remains in a position where the lubricant is uniformized on the image carrier. The presence of toner prevents chatter vibration and reversal of the image carrier protective agent uniformizing blade, and prevents or suppresses abnormal noise, abnormal wear, and cracks. In addition, contact with a constant load is applied. As a result, the contact pressure of the image carrier protective agent uniformizing blade to the image carrier is kept constant, so that the lubricant with the image carrier protective agent uniform blade is more uniform over time. Is, it is possible to provide a cleaning apparatus which can contribute to a more favorable image formation.

  Since the present invention is in a process cartridge having such a cleaning device, the residual toner passes between the ridge line portion of the cleaning blade and the image carrier, so that the image carrier protective agent uniformizing means removes the lubricant from the image carrier. Residual toner exists at the position to be uniformed above, and the lubricant is uniformized by the image carrier protective agent uniformizing means well over time, and can be handled as a replacement part that can contribute to good image formation. It is possible to provide a process cartridge with good maintainability.

  The present invention resides in such a cleaning device or an image forming apparatus having such a process cartridge, so that residual toner slips between the ridge line portion of the cleaning blade and the image carrier, so that the image carrier protective agent uniformizing means is provided. However, there is residual toner at a position where the lubricant is uniformized on the image carrier, and the uniformization of the lubricant by the image carrier protective agent uniformizing means is performed well over time, thereby forming a good image. It is possible to provide an image forming apparatus capable of performing the above.

  If toner having a circularity of 0.92 or more is used, residual toner slips between the ridge line portion of the cleaning blade and the image carrier, so that the image carrier protective agent uniformizing means removes the lubricant from the image. By setting the circularity in addition to the presence of residual toner at the position to be uniformized on the carrier, and the uniformization of the lubricant by the image carrier protective agent uniformizing means being performed well over time, An image forming apparatus capable of performing high-definition and better image formation with appropriate density reproducibility can be provided.

  If a toner having a shape factor SF-1 in the range of 100 to 180 and a shape factor SF-2 in the range of 100 to 180 is used, the gap between the ridge line portion of the cleaning blade and the image carrier is used. As the residual toner slips through, the residual toner is present at a position where the image carrier protective agent uniformizing means homogenizes the lubricant on the image carrier, and the image carrier protective agent uniformizing means equalizes the lubricant. In addition to being performed well over time, by setting such a shape, the fluidity and transferability of the toner are good, and the toner is prevented or suppressed from scattering on the image. An image forming apparatus capable of image formation can be provided.

  The volume average particle diameter (Dv) is in the range of 3 μm or more and 8 μm or less, and the dispersity defined by the ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is 1. If toner in the range of 05 or more and 1.40 or less is used, the residual toner slips between the ridge line portion of the cleaning blade and the image carrier, so that the image carrier protective agent uniformizing means removes the lubricant. In addition to the presence of residual toner at the position to be uniformized on the image carrier and the uniformization of the lubricant by the image carrier protective agent uniforming means being performed well over time, this ratio setting allows high image quality. Thus, it is possible to provide an image forming apparatus capable of performing better image formation with high resolution.

  The ratio (r2 / r1) of the length (r2) of the minor axis to the length (r1) of the major axis is in the range of 0.5 to 1.0, and the thickness (r3) and the length of the minor axis The ratio (r3 / r2) to the thickness (r2) is in the range of 0.7 to 1.0, and the length of the major axis (r1) ≧ the length of the minor axis (r2) ≧ the thickness ( If the toner satisfying the relationship r3) is used, the residual toner slips between the ridge line portion of the cleaning blade and the image carrier, so that the image carrier protective agent uniformizing means removes the lubricant on the image carrier. In addition to the fact that residual toner is present at the position to be uniformed and the uniformization of the lubricant by the image carrier protective agent uniformizing means is performed well over time, by setting such a shape, dot reproducibility, Good transfer efficiency and toner fluidity, enabling high-quality and better image formation It is possible to provide an image forming apparatus.

  In the toner, a toner composition containing a polyester polymer having a functional group containing a nitrogen atom, polyester, a colorant, and a release agent is crosslinked and / or extended in an aqueous medium in the presence of resin fine particles. If the toner is formed, the residual toner slips between the ridge line portion of the cleaning blade and the image carrier, so that the image carrier protective agent uniformizing means uniformly distributes the lubricant on the image carrier. In addition to the fact that residual toner is present at the position to be converted and the uniformizing of the lubricant by the image carrier protective agent uniformizing means is performed well over time, the toner has a small particle size and a sharp particle size distribution An image forming apparatus capable of performing better image formation can be provided.

  The present invention is an image forming method for forming an image using such a cleaning device, such a process cartridge, or such an image forming device, so that residual toner is present between the ridge line portion of the cleaning blade and the image carrier. By slipping through, residual toner exists at a position where the image carrier protective agent uniformizing means homogenizes the lubricant on the image carrier, and the uniformization of the lubricant by the image carrier protective agent uniforming means is good over time As a result, an image forming method capable of forming a good image can be provided.

1 is a schematic front view of an image forming apparatus to which the present invention is applied. FIG. 2 is a schematic front view showing a configuration around one image carrier among a plurality of image carriers provided in the image forming apparatus shown in FIG. FIG. 2 is a conceptual diagram for explaining toner shape factors SF-1 and SF-2 used in the image forming apparatus shown in FIG. 1; FIG. 2 is a conceptual diagram for explaining a mutual relationship between a major axis, a minor axis, and a thickness of toner used in the image forming apparatus illustrated in FIG. 1. FIG. 3 is a schematic front view showing the configuration and arrangement of a cleaning blade and an image carrier protective agent uniformizing blade provided in the cleaning device shown in FIG. 2.

  FIG. 1 shows an outline of an image forming apparatus to which the present invention is applied. The image forming apparatus 100 is a complex machine of a color laser copying machine and a printer, but may be other image forming apparatuses such as other types of copying machines, facsimile machines, printers, and complex machines of these. The image forming apparatus 100 performs image forming processing based on image data of a document read by the image forming apparatus 100 or an image signal corresponding to image information received from the outside. The image forming apparatus 100 can form an image using plain paper generally used for copying or the like as well as an OHP sheet, cardboard, postcard or other thick paper, or an envelope. .

  The image forming apparatus 100 is a cylindrical photosensitive drum that is a latent image carrier as an image carrier capable of forming an image as an image corresponding to each color separated into yellow, magenta, cyan, and black. A tandem structure in which 20Y, 20M, 20C, and 20BK are arranged in parallel, in other words, a tandem system is adopted.

  The photosensitive drums 20Y, 20M, 20C, and 20BK that are surface moving members are rotatably supported by a frame (not shown) of the main body 99 of the image forming apparatus 100, and are moved in the moving direction of the transfer belt 11 as a transfer medium that is an image carrier. They are arranged in this order from the upstream side in a certain A1 direction. Y, M, C, and BK added after the numerals of the respective symbols indicate members for yellow, magenta, cyan, and black.

  Each of the photosensitive drums 20Y, 20M, 20C, and 20BK is an image forming unit 60Y that is an image forming station for forming yellow (Y), magenta (M), cyan (C), and black (BK) images. It is provided in 60M, 60C and 60BK.

  The photosensitive drums 20Y, 20M, 20C, and 20BK are on the outer peripheral surface side of the transfer belt 11 as an intermediate transfer member, that is, an endless belt disposed slightly above the central portion inside the main body 99, that is, on the image forming surface side. Is located.

  The transfer belt 11 is movable in the direction of the arrow A1 while facing the photosensitive drums 20Y, 20M, 20C, and 20BK. Visible images, that is, toner images formed on the respective photoconductive drums 20Y, 20M, 20C, and 20BK are respectively superimposed and transferred onto the transfer belt 11 that moves in the direction of the arrow A1, and then transferred as a recording medium and a transfer medium. It is designed to be batch transferred onto paper. Illustration of the transfer paper is omitted.

  The upper portion of the transfer belt 11 faces the photosensitive drums 20Y, 20M, 20C, and 20BK, and the opposed portions transfer the toner images on the photosensitive drums 20Y, 20M, 20C, and 20BK. A primary transfer portion 98 for transferring to the belt 11 is formed.

  In the superimposing transfer to the transfer belt 11, the toner images formed on the photosensitive drums 20Y, 20M, 20C, and 20BK are transferred to the same position on the transfer belt 11 while the transfer belt 11 moves in the A1 direction. As described above, voltage application by the primary transfer rollers 12Y, 12M, 12C, and 12BK disposed at positions facing the photosensitive drums 20Y, 20M, 20C, and 20BK across the transfer belt 11 causes the A1 direction upstream. The timing is shifted toward the downstream side.

  The transfer belt 11 is a heat-resistant belt based on a resin film or rubber having a thickness of 20 to 600 μm as a base, and has a resistance value that enables electrostatic transfer of toner from the photosensitive drums 20Y, 20M, 20C, and 20BK. The surface roughness Rz is preferably about 1 to 4 μm.

  The image forming apparatus 100 is disposed in the main body 99 so as to oppose the four image forming units 60Y, 60M, 60C, and 60BK and the respective photosensitive drums 20Y, 20M, 20C, and 20BK. A transfer belt unit 10 serving as an intermediate transfer unit, and a transfer belt 11 that is disposed opposite to the transfer belt 11 and rotates in the same direction as the transfer belt 11 at an abutting position on the transfer belt 11 to move endlessly. And a secondary transfer unit 76 as a secondary transfer device that includes a secondary transfer belt 5 that is a paper transport belt as a transfer member and transfers and transfers the toner image on the transfer belt 11 to the transfer paper, and an image forming unit 60Y. , 60M, 60C, 60BK, an optical scanning unit, which is an optical writing unit serving as an exposure apparatus as a latent image forming unit disposed to face above And a 8.

  The image forming apparatus 100 also feeds a sheet as a sheet feeding cassette capable of stacking a large number of transfer sheets transported between the photosensitive drums 20Y, 20M, 20C, and 20BK and the transfer belt 11 in the main body 99. The sheet feeding device 61, which is a mechanism, and the transfer belt conveyed from the sheet feeding device 61 are transferred at a predetermined timing in accordance with the toner image formation timing by the image forming units 60Y, 60M, 60C, and 60BK. 11 and the secondary transfer belt 5, a registration roller 4 that feeds toward the secondary transfer portion 97, and a sensor (not shown) that detects that the leading edge of the transfer paper has reached the registration roller 4.

  The image forming apparatus 100 also includes a fixing device 6 as a belt-fixing type fixing unit for fixing the toner image onto the transfer paper onto which the toner image has been transferred, and a fixed transfer paper in the main body 99. A discharge roller 7 as a pair of discharge rollers to be discharged to the outside, and a discharge tray 17 on which the transfer sheets discharged to the outside of the main body 99 by the discharge roller 7 are stacked.

  The image forming apparatus 100 also includes a reading device 14 that is a scanner that reads an image of a document above the main body 99, and an automatic document feeder (so-called “original document feeding device”) that is disposed above the reading device 14 and feeds the document to the reading device 14. ADF) 15.

  The image forming apparatus 100 also includes a driving device (not shown) that rotationally drives the photosensitive drums 20Y, 20M, 20C, and 20BK, and a CPU that controls the overall operation of the image forming apparatus 100 based on detection results by various detection units. Control means (not shown) including a memory and the like.

  In addition to the transfer belt 11, the transfer belt unit 10 is wound around the transfer belt 11 and primary transfer rollers 12Y, 12M, 12C, and 12BK that are primary transfer bias rollers as primary transfer bias applying means. A driving roller 72 that is a driving member, a cleaning counter roller 74, stretching rollers 75 and 77 that stretch the transfer belt 11 together with the driving roller 72 and the cleaning counter roller 74, and a transfer roller 11 disposed opposite to the transfer belt 11. And a cleaning device 13 as a belt cleaning device for cleaning the belt 11.

  The transfer belt unit 10 also serves as a drive system (not shown) that rotationally drives the drive roller 72 and bias application means (not shown) that applies a high voltage to the primary transfer rollers 12Y, 12M, 12C, and 12BK and applies a primary transfer bias. Power supply and bias control means.

  The primary transfer rollers 12Y, 12M, 12C, and 12BK press the transfer belt 11 from the back surface thereof toward the photosensitive drums 20Y, 20M, 20C, and 20BK to form primary transfer nips. However, the primary transfer bias applying means may be a charger system that discharges from the electrode.

  In each primary transfer nip, a primary transfer electric field is formed between the photosensitive drums 20Y, 20M, 20C, and 20BK and the primary transfer rollers 12Y, 12M, 12C, and 12BK due to the influence of the primary transfer bias. . The toner images of the respective colors formed on the photosensitive drums 20Y, 20M, 20C, and 20BK are primarily transferred onto the transfer belt 11 due to the influence of the primary transfer electric field and nip pressure.

The driving roller 72 is in contact with the secondary transfer belt 5 via the transfer belt 11 to form a secondary transfer nip.
The tension roller 75 has a function as a tension roller as a pressure member that applies a predetermined tension suitable for transfer to the transfer belt 11, prevents the transfer belt 11 from being bent, and makes the transfer belt 11 smooth. Although it is moved to suppress the transfer unevenness and the deflection due to the movement of the transfer belt 11 is suppressed, other rollers around which the transfer belt 11 is wound, such as the tension roller 77, may be used as the tension roller. However, the tension roller is not essential.
The rollers around which the transfer belt 11 is wound are preferably grounded because the image is disturbed when the toner on the transfer belt 11 is moved by charging with friction with the transfer belt 11 and moving the toner.

  Although not shown in detail, the cleaning device 13 has a cleaning brush and a cleaning blade disposed so as to face and contact the transfer belt 11, and the residual transfer toner on the transfer belt 11. The transfer belt 11 is cleaned by scraping and removing foreign matters such as toner with a cleaning brush and a cleaning blade.

The sheet feeding device 61 accommodates a plurality of transfer papers in a state where a plurality of transfer papers are stacked, and is arranged in multiple stages below the main body 99. The sheet feeding device 61 feeds the transfer paper toward the registration roller 4 at a predetermined timing.
The transfer paper fed from the sheet feeding device 61 reaches the registration roller 4 through the paper feed path and is sandwiched between the rollers of the registration roller 4.

  In addition to the secondary transfer belt 5, the secondary transfer unit 76 is a tension roller around which the secondary transfer belt 5 is wound. The driving roller 72 is a backup roller as an opposing roller that is provided and pressed via the transfer belt 11, and a power source (not shown) that applies a secondary transfer bias having a polarity opposite to that of the toner to the driving roller 15.

  The drive roller 15 and the drive roller 72 sandwich the transfer belt 11 and the secondary transfer belt 5 between them, and the secondary transfer nip where the transfer belt 11 and the secondary transfer belt 5 come into contact with each other by the sandwiching. Is formed. In the secondary transfer nip, by applying a secondary transfer bias, a four-color toner image carried on the transfer belt 11 is electrostatically moved from the transfer belt 11 side to the drive roller 15 side as described later. A secondary transfer electric field is formed. The four-color toner image is transferred to a transfer sheet conveyed between the transfer belt 11 and the secondary transfer belt 5 by the registration roller 4 by a secondary transfer electric field and a nip pressure as will be described later.

  As the secondary transfer unit 76, a configuration using a transfer roller or a non-contact charger may be used, but in this case, another member for transporting the transfer paper toward the fixing device 6 is required.

  The fixing device 6 includes a belt unit 62 and a pressure roller 63 pressed against the belt unit 62. The belt unit 62 includes an endless fixing belt 64, a fixing roller 65 that moves the fixing belt 64 in an endless manner, and a heating roller 66 that has the fixing belt 64 wound around the fixing roller 65 and has a heat source (not shown) inside. have

  The fixing device 6 passes the transfer paper carrying the toner image through a fixing unit, which is a pressure contact part between the belt unit 62 and the pressure roller 63, so that the carried toner image is caused by the action of heat and pressure. It is fixed on the surface of the transfer paper.

  The configuration of the image forming units 60Y, 60M, 60C, and 60BK will be described as a representative of the configuration of the image forming unit 60Y that includes the photosensitive drum 20Y. Since the configurations of the other image forming units are substantially the same, in the following description, for the sake of convenience, reference numerals corresponding to the reference numerals assigned to the configuration of the image forming unit 60Y are used for the configurations of the other image forming units. Or omitted, and detailed description will be omitted as appropriate.

  As shown in FIG. 2, the image forming unit 60Y provided with the photosensitive drum 20Y performs primary transfer around the photosensitive drum 20Y along a rotational direction B1 that is a counterclockwise direction in the drawing. A roller 12Y, a cleaning device 70Y which is a drum cleaning device as a cleaning device, a static eliminator provided with a neutralizing lamp (not shown) as a static eliminator, a charging device 90Y as a charging device, and a developing unit as a developing device. And a developing device 80Y as a developing device.

  The image forming unit 60Y is a protective film forming apparatus that applies a protective agent 42Y as an image carrier protective agent for protecting the photosensitive drum 20Y to the photosensitive drum 20Y and forms a protective film on the surface of the photosensitive drum 20Y. A coating device 40Y as an image carrier protecting agent coating device is included as a part of the cleaning device 70Y.

  The photosensitive drum 20Y, the cleaning device 70Y, the static eliminator, the charging device 90Y, the developing device 80Y, and the coating device 40Y are integrated by a casing 67Y as a process cartridge frame that covers them. A process cartridge 68Y is configured together with 67Y. The process cartridge 68Y is detachable from the main body 99. Making a process cartridge in this way is very preferable because it can be handled as a replacement part, so that the maintainability is remarkably improved.

  The photosensitive drum 20Y has a structure in which a photosensitive layer of an organic semiconductor, which is a photoconductive substance, is provided on the surface of a conductive support made of an aluminum cylinder having a diameter of about 30 to 100 mm. It may be a configuration having a belt shape or a belt shape.

  The charging device 90Y is a uniform charging unit that uniformly charges the surface of the photosensitive drum 20Y, and includes a charging roller 91Y as a charging member disposed in proximity to the surface of the photosensitive drum 20Y, and a charging roller. The cleaning roller 92Y is disposed in contact with 91Y and cleans the charging roller 91Y, and a high voltage power source (not shown) that applies a voltage obtained by superimposing a DC voltage and an AC voltage to the charging roller 91Y.

  As a method for charging the photosensitive drum 20Y, a charging member such as the charging roller 91Y is used in addition to the proximity method in which the charging roller 91Y is arranged in non-contact with the photosensitive drum 20Y as in the charging device 90Y of this embodiment. There is a contact charging method in which the photosensitive drum 20Y is arranged in contact with the photosensitive drum 20Y, that is, a contact method. The high voltage power supply may apply only a DC voltage to the charging roller 91Y.

  The charging device 90Y charges the photosensitive drum 20Y by proximity discharge in a minute gap between the charging roller 91Y and the photosensitive drum 20Y by voltage application from a high voltage power source. Therefore, compared to a so-called corotron or scorotron discharger using a corona discharge using a discharge wire, the amount of ozone generated during charging is greatly suppressed.

  The optical scanning device 8 modulates light based on light information converted in accordance with image information into a region between a charging area where the charging device 90Y faces the photosensitive drum 20Y and a developing area where the developing device 80Y faces. Then, the deflected laser beam L is irradiated while scanning, the surface to be scanned of the photosensitive drum 20Y after being charged by the charging device 90Y is exposed by spot irradiation, and can be converted into a yellow toner image by the developing device 80Y. An electrostatic latent image corresponding to image information to be visualized is written. Therefore, as shown in FIG. 1, the optical scanning device 8 includes a light source 31, a polygon mirror 32 that is a polygonal polygon mirror that rotates at high speed, an fθ lens 33, a reflection mirror 34, and the like. The optical scanning device 8 may be a system having an LED array and an imaging means.

  As shown in FIG. 2, the developing device 80Y includes a developing roller 81Y disposed close to and facing the photosensitive drum 20Y, a doctor blade 82Y that regulates the developer on the developing roller 81Y to a certain height, A first transport screw 83Y and a second transport screw 84Y, which are arranged so as to face each other and stir the developer and supply the developer to the developing roller 81Y, and a first transport screw 83Y and a second transport screw 84Y. A partition wall 87Y provided between the toner bottle 88Y, a toner bottle 88Y containing yellow toner, a developing case 85Y forming a part of the casing 67Y, and a bias application (not shown) for applying a DC component developing bias to the developing roller 81Y. Means and the like.

  The developing roller 81Y has a developing sleeve (not shown) that is a developer carrying member that carries the developer on the surface thereof. The bias applying means applies a developing bias having an appropriate size between the exposed portion and the non-exposed portion of the photosensitive drum 20Y to the developing sleeve.

  In the developing device 80Y, a partition wall 87Y forms a first supply unit that accommodates the developing roller 81Y and the first conveyance screw 83Y and a second supply unit that accommodates the second conveyance screw 84Y. Has been.

  The first transport screw 83Y is rotationally driven by a driving unit, and supplies the developer in the first supply unit to the developing roller 81Y while transporting the developer from the back side to the front side in FIG. The developer conveyed to the vicinity of the end in the first supply unit by the first conveyance screw 83Y enters the second supply unit through an opening (not shown) formed in the partition wall 87Y.

  In the second supply unit, the second transport screw 84Y transports the developer sent from the first supply unit in the direction opposite to that of the first transport screw 83Y by being rotationally driven by the driving unit. The developer transported to the vicinity of the end of the second supply unit by the second transport screw 84Y returns to the first supply unit through another opening (not shown) provided in the partition wall 87Y.

  The developer in the developing case 85Y is a two-component developer containing a magnetic carrier and yellow toner. The developer is supplied and supplied with yellow toner from the toner bottle 88Y, and the first transport screw 83Y and The supplied yellow toner and developer are agitated and mixed while being agitated and conveyed by the second conveying screw 84Y, are frictionally charged, and are supplied and carried on the developing roller 81Y.

  The developing roller 81Y whose developer thickness is regulated by the doctor blade 82Y and whose layer thickness is regulated is developed in the developing region between the developing roller 81Y and the photosensitive drum 20Y by the rotation and the developing bias by the bias applying means. An appropriate amount of developer is carried by the doctor blade 82Y, and the yellow toner in the developer is electrostatically transferred to the electrostatic latent image formed on the surface of the photosensitive drum 20Y, and the electrostatic latent image is formed. A visible image is formed as a yellow toner image.

The developer that has consumed the yellow toner by the development is returned to the developing device 80Y as the developing roller 81Y rotates.
In this embodiment, the DC component developing bias is applied by the bias applying means. However, the developing bias may be an AC component, or an AC component superimposed on the DC component.
Details of the toner used in the developing device 80Y and other developing devices provided in the image forming apparatus 100 will be described later.

  In addition to the coating device 40Y, the cleaning device 70Y includes a cleaning case 71Y that forms part of the casing 67Y, a residual toner that is a transfer residual toner on the photosensitive drum 20Y, a carrier, A cleaning blade 78Y that scrapes and collects and removes foreign matters such as paper dust, a blade support member 51Y as a blade holder that rotatably supports the cleaning blade 78Y on the cleaning case 71Y, and a blade support member 51Y And a spring 79Y that is a pressure spring that presses the cleaning blade 78Y against the photosensitive drum 20Y with a predetermined elastic force.

  The cleaning device 70Y also contacts the photosensitive drum 20Y on the upstream side in the B1 direction from the position where the cleaning blade 78Y contacts the photosensitive drum 20Y and removes foreign matters such as residual toner, carrier, and paper dust on the photosensitive drum 20Y. It is supported by a brush roller 52Y, which is a fur brush as a rotating brush that is a cleaning brush that facilitates the removal of the foreign matter by the scratching cleaning blade 78Y and scrapes and cleans a part of the foreign matter, and the blade support member 51Y. The front end is in contact with the brush roller 52Y, and has a flicker bar 53Y which is a flicker as a scraping member that flickers and blows off foreign matter adhering to the brush roller 52Y by rotation of the brush roller 52Y.

  The cleaning device 70Y is also rotatably supported by the cleaning case 71Y. The cleaning device 70Y is scraped off from the photosensitive drum 20Y by the brush roller 52Y and the cleaning blade 78Y and removed, or the brush roller 52Y by the flicker bar 53Y. A discharge screw 54Y serving as a collection coil that constitutes a part of a waste toner path (not shown) and a brush roller 52Y are photosensitive to convey foreign matter knocked down and discharged from a waste toner tank (not shown). A pre-cleaning static elimination lamp 55Y is provided as a pre-cleaning static elimination means for irradiating the photosensitive drum 20Y with light on the upstream side in the B1 direction from the position in contact with the photosensitive drum 20Y to neutralize the photosensitive drum 20Y.

  The cleaning device 70Y also has a partition wall 57Y for blocking between the cleaning blade 78Y and the coating device 40Y, and a waste toner path (not shown) for transporting foreign matter accumulated on the partition wall 57Y toward a waste toner tank (not shown). And a discharge screw 58Y which is a conveying screw as a recovery coil that constitutes a part of this.

  The cleaning blade 78Y extends in a direction perpendicular to the paper surface in the figure, which is the longitudinal direction of the photosensitive drum 20Y, and is in a so-called counter contact with the photosensitive drum 20Y. The contact condition is a so-called trailing contact. The cleaning performance is higher than in some cases. The cleaning blade 78Y uses a fluorine resin, urethane resin, or silicone resin elastomer in a blade shape. The material of the cleaning blade 78Y is particularly preferably a urethane resin that has high elasticity and is difficult to wear. The cleaning blade 78Y is in contact with the photosensitive drum 20Y with a contact pressure of 5 to 30 N / m by the biasing force of the spring 79Y.

  The brush roller 52Y rotates in a direction that rotates in the B1 direction. As a material of the brush roller 52Y, a polyamide resin such as nylon that is resistant to wear and has high strength can be used in addition to a polyester resin, a fluororesin, a styrene resin, and an acrylic resin. In order to prevent frictional charging, the brush roller 52Y contains carbon black such as acetylene black and furnace black, graphite, or metal powder such as copper and silver as conductive powder. Also good. Specifically, the electric resistance of the brush roller 52Y is preferably in the range of 10 ^ 2 to 10 ^ 8 Ω · cm.

  The coating device 40Y has a protective agent 42Y, which is a solid lubricant formed in a bar shape and extends in the longitudinal direction of the photosensitive drum 20Y, and a position downstream of the B1 direction from the position where the cleaning blade 78Y contacts the photosensitive drum 20Y. The protective agent supply means 56Y for supplying the protective agent 42Y to the photosensitive drum 20Y on the side, and the protective agent supply means on the downstream side in the B1 direction from the position where the protective agent 42Y is supplied to the photosensitive drum 20Y by the protective agent supply means 56Y. Protective layer forming mechanism 49Y as an image carrier protective agent uniformizing means for applying and uniforming the protective agent 42Y applied or supplied to the photosensitive drum 20Y by 56Y on the surface of the photosensitive drum 20Y to form a protective film. And have.

  The protective agent 42Y is made of a fatty acid such as lead oleate, zinc oleate, copper oleate, zinc stearate, cobalt stearate, iron stearate, copper stearate, zinc palmitate, copper palmitate or zinc linolenate. Metal salts, polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polytrifluorochloroethylene, dichlorodifluoroethylene, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-oxafluoropropylene copolymer, etc. Fluorine-based resin. In particular, the fatty acid metal salt is highly effective in reducing the friction of the photosensitive drum 20Y, and stearic acid is used as the fatty acid, and zinc stearate or calcium stearate using zinc or calcium as the metal is more preferable.

  The protective agent supply means 56Y scrapes off the protective agent 42Y to protect the photosensitive drum 20Y, and comes into contact with the photosensitive drum 20Y on the downstream side in the B1 direction from the position where the cleaning blade 78Y comes into contact with the photosensitive drum 20Y. The brush roller 47Y, which is a fur brush, which is an application brush, which is a scraping member, which is a supply member, which supplies the protective agent, and the surface of the protective agent 42Y, which is opposite to the surface on the photosensitive drum 20Y side, are supported. A holder 41Y as a bracket and a spring 48Y as a pressure spring as a pressing force applying mechanism as an elastic member for pressing the protective agent 42Y against the brush roller 47Y through the holder 41Y are provided.

  The protective agent supply means 56Y is also a protective agent supply member drive means (not shown) that rotates the brush roller 47Y in a direction opposite to the direction of rotation in the B1 direction at a position where the brush roller 47Y contacts the photosensitive drum 20Y. have. The protective agent supply member driving means includes a motor (not shown) as a drive source for rotating the brush roller 47Y in this direction, and a gear (not shown) for inputting the rotation of the motor to a shaft (not shown) of the brush roller 47Y. . The protective agent supply member driving means is also provided with a gear (not shown) for inputting the rotation of the motor to a shaft (not shown) of the brush roller 52Y, and also functions as a cleaning brush driving means for driving the brush roller 52Y to rotate in the above-described direction. It is supposed to be.

  As the brush roller 47Y rotates in this direction, the fibers constituting the brush roller 47Y from which the protective agent 42Y has been scraped off are flicked to the photosensitive drum 20Y at the exit side of the contact portion with the surface of the photosensitive drum 20Y, and the brush roller 47Y The powder of the protective agent 42Y is blown off upstream from the contact portion between the photosensitive drum 20Y and the photosensitive drum 20Y, and then adheres to the surface of the photosensitive drum 20Y again, and again on the contact portion between the brush roller 47Y and the photosensitive drum 20Y. Then, the surface of the photosensitive drum 20Y is once again applied by the brush roller 47Y, so that the coating efficiency is improved and the thinning of the protective agent 42Y is achieved with high efficiency.

  As a material of the brush roller 47Y, polyamide resin such as nylon that is strong against abrasion and high in strength can be used in addition to polyester resin, fluororesin, styrene resin, and acrylic resin. In order to prevent frictional charging, the brush roller 47Y contains conductive powder of carbon powder such as acetylene black and furnace black, graphite, or metal powder such as copper and silver as conductive powder. Also good. Specifically, the electric resistance of the brush roller 47Y is preferably in the range of 10 ^ 2 to 10 ^ 8 Ω · cm.

  The length of the protective agent 42Y and the brush roller 47Y in the longitudinal direction of the photosensitive drum 20Y is the width direction so that the protective agent 42Y is scraped and consumed uniformly in the width direction by the brush roller 47Y. Are coincident with each other, and the arrangement ranges in the width direction are coincident with each other. Further, the urging force of the spring 48Y is configured to press the protective agent 42Y against the brush roller 47Y with a constant pressure of 3N even in the longitudinal direction.

  The protective agent 42Y and the brush roller 47Y have a length in the width direction that is at least the length of the image forming area of the photosensitive drum 20Y in the same direction, and the arrangement of the protective agent 42Y and the brush roller 47Y in the same direction. The installation position is configured to include the image forming area of the photosensitive drum 20Y. Therefore, the protective agent 42Y is uniformly supplied to the image forming area of the photosensitive drum 20Y by the brush roller 47Y in the width direction.

  The protective layer forming mechanism 49Y is in contact with the photosensitive drum 20Y on the downstream side in the B1 direction from the position where the protective agent 42Y is applied to or supplied to the photosensitive drum 20Y by the brush roller 47Y, and the photosensitive member by the brush roller 47Y. Protecting the image carrier as a film-forming member that is a layered member that coats or supplies the protective agent 42Y applied or supplied to the drum 20Y onto the surface of the photoreceptor drum 20Y to make it uniform, layered, and thinly formed into a thin film. A coating blade 45Y, which is a uniform agent blade, and a blade constant load support means 43Y for supporting the coating blade 45Y and bringing the coating blade 45Y into contact with the photosensitive drum 20Y with a constant load.

  The coating blade 45Y extends in a direction perpendicular to the paper surface in the figure, which is the longitudinal direction of the photosensitive drum 20Y, and is in so-called counter contact with the photosensitive drum 20Y. The contact condition is so-called trailing contact. The application performance is higher than in some cases. The coating blade 45Y uses a fluorine resin, urethane resin, or silicone resin elastomer in a blade shape. The material of the coating blade 45Y is particularly preferably a urethane resin that has high elasticity and is not easily worn. The coating blade 45Y is in contact with the photosensitive drum 20Y with a contact pressure of 5 to 30 N / m by the biasing force of the spring 44.

  The blade constant load support means 43Y includes a blade support member 46Y as a blade holder that rotatably supports the application blade 45Y on the cleaning case 71Y, and the application blade 45Y via the blade support member 46Y. And a spring 44Y which is a lubricant pressurizing spring as an elastic member that presses against the spring with a predetermined elastic force. The spring 44Y causes the coating blade 45Y to contact the photosensitive drum 20Y with a constant load of 5 to 30 N / m, so that the contact pressure of the coating blade 45Y with respect to the photosensitive drum 20Y is stabilized. The lubricant application function is exhibited well. The blade supporting member 46Y may be fixed to the cleaning case 71Y, and the coating blade 45Y may be fixedly supported by, for example, a blade fixing support means for fixing and supporting the coating blade 45Y. The posture of the coating blade 45Y with respect to 20Y is constant and stable, and the lubricant coating function by the coating blade 45Y is exhibited well.

  The coating blade 45Y and the blade support 46Y are fixed to each other by adhesion so that the tip of the coating blade 45Y can bear the pressure contact with the surface of the photosensitive drum 20Y. They may be fixed to each other by this method.

  The coating blade 45Y has a length in the width direction that is equal to or greater than the length of the image forming area of the photosensitive drum 20Y in the same direction, and the arrangement position thereof includes the image forming area of the photosensitive drum 20Y in the same direction. It is configured. Accordingly, the coating blade 45Y uniformly contacts at least the image forming area of the photosensitive drum 20Y in the width direction, and forms a film at least in the image forming area on the photosensitive drum 20Y in the width direction.

  The coating device 40Y having such a configuration rotates the brush roller 47Y around the axis in the above-described direction, scrapes off the protective agent 42Y, and once pumps up the scraped protective agent 42Y. The photosensitive drum 20Y is coated and supplied after being carried and conveyed to a contact position with the surface.

  The protective agent 42Y applied to the photosensitive drum 20Y may not form a sufficient protective layer on the photosensitive drum 20Y depending on the material type of the protective agent 42Y. It is pressed against the surface of the drum 20Y and stretched to reduce the thickness, in other words, it is layered, formed into a film, and is made uniform, so that the film formation of the protective agent is reliably and uniformly applied.

  Even if the protective agent 42Y is scraped off and reduced by the brush roller 47Y over time, the spring 48Y uniformly presses the protective agent 42Y in the longitudinal direction against the brush roller 47Y with a constant pressure even over time. Even if the amount is small, an appropriate amount is pumped up to the brush roller 47Y and supplied to the photosensitive drum 20Y.

  The film formed on the surface of the photoconductive drum 20Y by the protective agent 42Y has a function of preventing the surface of the photoconductive drum 20Y from being deteriorated due to proximity discharge in a minute gap between the charging roller 91Y and the photoconductive drum 20Y. The coating device 40Y functions as discharge deterioration preventing means. The deterioration here refers to both wear of the photosensitive drum 20Y due to discharge, acceleration of the wear, and activation of the surface of the photosensitive drum 20Y.

  In addition, such a film prevents deterioration due to wear or the like caused by friction between the photosensitive drum 20Y and the cleaning blade 78Y, and deterioration due to filming of the surface of the photosensitive drum 20Y by such friction. The device 40Y functions as a friction deterioration preventing means.

Thus, the coating device 40Y eliminates all of these deteriorations by applying the protective agent 42Y to the surface of the photosensitive drum 20Y.
In addition, details of the configuration and functions of the cleaning blade 78Y, the coating blade 45Y, the partition wall 57, the discharge screw 58Y, etc., and the functions of the coating device 40Y and the cleaning device 70Y related thereto will be described later.

  The toner used for development in the image forming apparatus 100 will be described in detail.

  The toner has a volume average particle diameter (Dv) of 10 μm or less, particularly 3 μm or more and 8 μm or less, and is defined by a ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn). The dispersity is preferably in the range of 1.05 to 1.40.

  By using the toner having a small particle diameter, the toner adheres densely to the latent image. However, when the volume average particle size is smaller than this range, in the case of a two-component developer, the toner is fused to the surface of the magnetic carrier during long-term agitation in the developing device, and the charging ability of the magnetic carrier is lowered. When it is used, toner filming on the developing roller and toner fusion to a member such as a blade for thinning the toner are likely to occur. Conversely, when the volume average particle size of the toner is larger than this range, it becomes difficult to obtain a high-resolution and high-quality image, and the toner balance in the developer is reduced. In many cases, the variation of the particle size becomes large.

  Further, by narrowing the particle size distribution, the toner charge amount distribution becomes uniform, a high-quality image with little background fogging can be obtained, and the transfer rate can be increased. However, when the degree of dispersion (Dv / Dn) exceeds 1.40, the charge amount distribution becomes wide and the resolution is also lowered, which is not preferable.

  The average particle diameter and particle size distribution of the toner can be measured using a Coulter Counter TA-II and Coulter Multisizer II (both manufactured by Coulter). In the present invention, a Coulter counter TA-II type was used, connected to an interface (manufactured by Nikka Giken) and a personal computer (PC9801: manufactured by NEC) to output the number distribution and volume distribution.

The circularity of the toner, that is, the average circularity, is preferably 0.92 or more and 1.00 or less.
The circularity is one of the parameters representing the toner shape.

  It is important that the toner has a specific shape and shape distribution, and an irregularly shaped toner having an average circularity of less than 0.92 and far away from a spherical shape has a satisfactory transferability and a high density without dust. A quality image cannot be obtained.

  As a method for measuring the shape, an optical detection band method is suitable in which a suspension containing particles is passed through an imaging unit detection band on a flat plate, and a particle image is optically detected and analyzed by a CCD camera. Details will be described later.

  A toner having an average circularity of 0.92 or more and 1.00 or less, which is a value obtained by dividing the perimeter of an equivalent circle having the same projected area obtained by this method by the perimeter of the actual particle, has a high reproducibility with an appropriate density. It turned out to be effective for forming a fine image. More preferably, particles having an average circularity of 0.93 to 0.97 and a circularity of less than 0.94 are 10% or less.

  When the average circularity is less than 0.92, for example, when an image with a low image area ratio is output, the amount of residual toner is small and cleaning failure does not cause a problem. When a high image is output, and further, an untransferred image remains on the photosensitive drum 20 due to a paper feed failure or the like, a cleaning failure is likely to occur.

  The average circularity of the toner is a value obtained by optically detecting particles and dividing by the perimeter of an equivalent circle having the same projected area. Specifically, the measurement is performed using a flow type particle image analyzer (FPIA-2000; manufactured by Sysmex Corporation). In a predetermined container, 100 to 150 mL of water from which impure solids are removed in advance is added, 0.1 to 0.5 mL of a surfactant is added as a dispersant, and about 0.1 to 9.5 g of a measurement sample is further added. The suspension in which the sample is dispersed is subjected to dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the concentration and dispersion of the dispersion are set to 3,000 to 10,000 / μL, and the shape and distribution of the toner are measured.

  The toner used in the image forming apparatus 100 preferably has a shape factor SF-1 in the range of 100 to 180 and a shape factor SF-2 in the range of 100 to 180.

  FIG. 3 is a diagram schematically illustrating the shape of the toner in order to explain the shape factor SF-1 and the shape factor SF-2.

  The shape factor SF-1 indicates the ratio of the roundness of the toner shape and is represented by the following formula (1). This is a value obtained by dividing the square of the maximum length MXLNG of the shape formed by projecting the toner on a two-dimensional plane by the figure area AREA and multiplying by 100π / 4.

SF-1 = {(MXLNG) 2 / AREA} × (100π / 4) Formula (1)
When the value of SF-1 is 100, the shape of the toner becomes a true sphere, and becomes larger as the value of SF-1 increases.

  The shape factor SF-2 indicates the ratio of the unevenness of the toner shape, and is represented by the following formula (2). A value obtained by dividing the square of the perimeter PERI of the figure formed by projecting the toner onto the two-dimensional plane by the figure area AREA and multiplying by 100 / 4π.

SF-2 = {(PERI) 2 / AREA} × (100 / 4π) (2)
When the value of SF-2 is 100, there is no unevenness on the toner surface, and as the value of SF-2 increases, the unevenness of the toner surface becomes more prominent.

  When the shape of the toner is close to a spherical shape, the contact between the toner and the toner or the toner and the photosensitive drum 20 is close to a point contact, so that the adsorbing force between the toners is weakened and the fluidity is increased. The attracting force with the photosensitive drum 20 is also weakened, and the transfer rate is increased. On the other hand, since the spherical toner easily enters the gap between the cleaning blade 78Y or the coating blade 45Y and the photosensitive drum 20Y, the toner shape factor SF-1 or SF-2 is preferably large to some extent. Further, when SF-1 and SF-2 are increased, toner is scattered on the image and the image quality is lowered. For this reason, it is preferable that SF-1 and SF-2 do not exceed 180.

  Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope (S-800: manufactured by Hitachi, Ltd.) and introducing it into an image analyzer (LUSEX 3: manufactured by Nireco) for analysis. And calculated.

  The toner suitably used in the image forming apparatus 100 is, for example, a toner in which a toner composition including at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent is dispersed in an organic solvent. A toner obtained by subjecting a material liquid to a crosslinking and / or elongation reaction in the presence of resin fine particles in an aqueous solvent. Hereinafter, examples of the constituent material and the manufacturing method of the toner will be described.

(Modified polyester)
The toner contains modified polyester (i) as a binder resin. The modified polyester (i) refers to a state in which a bonding group other than an ester bond is present in the polyester resin, or resin components having different configurations are bonded to the polyester resin by a covalent bond, an ionic bond, or the like. Specifically, the polyester terminal is modified by introducing a functional group such as a carboxylic acid group or an isocyanate group that reacts with a hydroxyl group into the polyester terminal and further reacting with an active hydrogen-containing compound.

  Examples of the modified polyester (i) include urea-modified polyester obtained by a reaction between a polyester prepolymer (A) having an isocyanate group and amines (B). As the polyester prepolymer (A) having an isocyanate group, a polyester having a polycondensate of a polyhydric alcohol (PO) and a polyvalent carboxylic acid (PC) and having an active hydrogen group is further added to a polyvalent isocyanate compound (PIC). And those reacted with. Examples of the active hydrogen group possessed by the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, and the like. Among these, an alcoholic hydroxyl group is preferable.

  The urea-modified polyester is produced as follows.

  Examples of the polyhydric alcohol compound (PO) include dihydric alcohol (DIO) and trihydric or higher polyhydric alcohol (TO). (DIO) alone or a mixture of (DIO) and a small amount of (TO) preferable. Examples of the dihydric alcohol (DIO) include alkylene glycol (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, etc.); alkylene ether glycol (diethylene glycol) , Triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, etc.); alicyclic diols (1,4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); bisphenols (bisphenol A, bisphenol) F, bisphenol S, etc.); alkylene oxide (ethylene oxide, propylene oxide, butylene oxide, etc.) adduct of the above alicyclic diol; Alkylene oxide bisphenol (ethylene oxide, propylene oxide, butylene oxide, etc.), etc. adducts. Among them, preferred are alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols, and particularly preferred are alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms. It is a combined use. The trihydric or higher polyhydric alcohol (TO) includes 3 to 8 or higher polyhydric aliphatic alcohols (glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, sorbitol, etc.); trihydric or higher phenols (Trisphenol PA, phenol novolak, cresol novolak, etc.); and alkylene oxide adducts of the above trivalent or higher polyphenols.

  Examples of the polyvalent carboxylic acid (PC) include divalent carboxylic acid (DIC) and trivalent or higher polyvalent carboxylic acid (TC). (DIC) alone and (DIC) with a small amount of (TC) Mixtures are preferred. Divalent carboxylic acids (DIC) include alkylene dicarboxylic acids (succinic acid, adipic acid, sebacic acid, etc.); alkenylene dicarboxylic acids (maleic acid, fumaric acid, etc.); aromatic dicarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid) And naphthalenedicarboxylic acid). Of these, preferred are alkenylene dicarboxylic acids having 4 to 20 carbon atoms and aromatic dicarboxylic acids having 8 to 20 carbon atoms. Examples of the trivalent or higher polyvalent carboxylic acid (TC) include aromatic polycarboxylic acids having 9 to 20 carbon atoms (such as trimellitic acid and pyromellitic acid). In addition, as polyhydric carboxylic acid (PC), you may make it react with polyhydric alcohol (PO) using the above-mentioned acid anhydride or lower alkyl ester (Methyl ester, ethyl ester, isopropyl ester, etc.).

  The ratio of the polyhydric alcohol (PO) to the polycarboxylic acid (PC) is usually 2/1 to 1/1, preferably as the equivalent ratio [OH] / [COOH] of the hydroxyl group [OH] and the carboxyl group [COOH]. Is 1.5 / 1 to 1/1, more preferably 1.3 / 1 to 1.02 / 1.

  Examples of the polyvalent isocyanate compound (PIC) include aliphatic polyisocyanates (tetramethylene diisocyanate, hexamethylene diisocyanate, 2,6-diisocyanatomethylcaproate, etc.); alicyclic polyisocyanates (isophorone diisocyanate, cyclohexylmethane diisocyanate, etc.) ); Aromatic diisocyanates (tolylene diisocyanate, diphenylmethane diisocyanate, etc.); araliphatic diisocyanates (α, α, α ′, α′-tetramethylxylylene diisocyanate, etc.); isocyanates; Those blocked with caprolactam or the like; and combinations of two or more of these.

  The ratio of the polyvalent isocyanate compound (PIC) is usually 5/1 to 1/1, preferably as an equivalent ratio [NCO] / [OH] of the isocyanate group [NCO] and the hydroxyl group [OH] of the polyester having a hydroxyl group. 4/1 to 1.2 / 1, more preferably 2.5 / 1 to 1.5 / 1. When [NCO] / [OH] exceeds 5, low-temperature fixability deteriorates. When the molar ratio of [NCO] is less than 1, when a urea-modified polyester is used, the urea content in the ester is lowered and hot offset resistance is deteriorated.

  The content of the polyvalent isocyanate compound (PIC) component in the polyester prepolymer (A) having an isocyanate group is usually 0.5 to 40 wt%, preferably 1 to 30 wt%, more preferably 2 to 20 wt%. . If it is less than 0.5 wt%, the hot offset resistance deteriorates, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. On the other hand, if it exceeds 40 wt%, the low-temperature fixability deteriorates.

The number of isocyanate groups contained per molecule in the polyester prepolymer (A) having an isocyanate group is usually 1 or more, preferably 1.5 to 3 on average, more preferably 1.8 to 2 on average. Five. If it is less than 1 per molecule, the molecular weight of the urea-modified polyester will be low, and the hot offset resistance will deteriorate.
Next, as amines (B) to be reacted with the polyester prepolymer (A), a divalent amine compound (B1), a trivalent or higher polyvalent amine compound (B2), an amino alcohol (B3), an amino mercaptan (B4) ), Amino acid (B5), and amino acid block of B1 to B5 (B6).

  Examples of the divalent amine compound (B1) include aromatic diamines (phenylenediamine, diethyltoluenediamine, 4,4′-diaminodiphenylmethane, etc.); alicyclic diamines (4,4′-diamino-3,3′-dimethyldicyclohexyl). Methane, diamine cyclohexane, isophorone diamine, etc.); and aliphatic diamines (ethylene diamine, tetramethylene diamine, hexamethylene diamine, etc.) and the like. Examples of the trivalent or higher polyvalent amine compound (B2) include diethylenetriamine and triethylenetetramine. Examples of amino alcohol (B3) include ethanolamine and hydroxyethylaniline. Examples of amino mercaptan (B4) include aminoethyl mercaptan and aminopropyl mercaptan. Examples of the amino acid (B5) include aminopropionic acid and aminocaproic acid. Examples of B1 to B5 blocked amino groups (B6) include ketimine compounds and oxazolidine compounds obtained from the amines of B1 to B5 and ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.). Among these amines (B), preferred are B1 and a mixture of B1 and a small amount of B2.

  The ratio of amines (B) is equivalent to the equivalent ratio [NCO] / [NHx] of isocyanate groups [NCO] in the polyester prepolymer (A) having isocyanate groups and amino groups [NHx] in amines (B). Is usually 1/2 to 2/1, preferably 1.5 / 1 to 1 / 1.5, more preferably 1.2 / 1 to 1 / 1.2. When [NCO] / [NHx] is more than 2 or less than 1/2, the molecular weight of the urea-modified polyester is lowered, and the hot offset resistance is deteriorated.

  The urea-modified polyester may contain a urethane bond together with a urea bond. The molar ratio of the urea bond content to the urethane bond content is usually 100/0 to 10/90, preferably 80/20 to 20/80, and more preferably 60/40 to 30/70. When the molar ratio of the urea bond is less than 10%, the hot offset resistance is deteriorated.

  The modified polyester (i) is produced by a one-shot method or a prepolymer method. The weight average molecular weight of the modified polyester (i) is usually 10,000 or more, preferably 20,000 to 10,000,000, more preferably 30,000 to 1,000,000. The peak molecular weight at this time is preferably 1000 to 10000. When the molecular weight is less than 1000, the elongation reaction hardly occurs, the elasticity of the toner is small, and as a result, the resistance to hot offset deteriorates. On the other hand, when it exceeds 10,000, the problem in production becomes high in the deterioration of fixability, particle formation and pulverization. The number average molecular weight of the modified polyester (i) is not particularly limited when the unmodified polyester (ii) described later is used, and may be a number average molecular weight that can be easily obtained to obtain the weight average molecular weight. (I) When used alone, the number average molecular weight is usually 20000 or less, preferably 1000 to 10000, and more preferably 2000 to 8000. When it exceeds 20000, the low-temperature fixability and the glossiness when used in a full-color device are deteriorated.

  In the crosslinking and / or extension reaction between the polyester prepolymer (A) and the amines (B) to obtain the modified polyester (i), a reaction terminator is used as necessary to adjust the molecular weight of the resulting urea-modified polyester. be able to. Examples of the reaction terminator include monoamines (diethylamine, dibutylamine, butylamine, laurylamine, etc.), and those obtained by blocking them (ketimine compounds).

The molecular weight of the polymer produced can be measured using gel permeation chromatography (GPC) with THF as a solvent.
(Unmodified polyester)

  Not only the modified polyester (i) is used alone, but also the unmodified polyester (ii) can be contained as a binder resin component together with the (i). By using (ii) in combination, the low-temperature fixability and the gloss when used in a full-color device are improved, which is preferable to single use. Examples of (ii) include polycondensates of polyhydric alcohol (PO) and polyvalent carboxylic acid (PC) similar to the polyester component of (i), and preferred ones are also the same as (i). . (Ii) is not limited to unmodified polyester, but may be modified with a chemical bond other than a urea bond, and may be modified with a urethane bond, for example. It is preferable that (i) and (ii) are at least partially compatible in terms of low-temperature fixability and hot offset resistance. Accordingly, the polyester component (i) and (ii) preferably have similar compositions. When (ii) is contained, the weight ratio of (i) to (ii) is usually 5/95 to 80/20, preferably 5/95 to 30/70, more preferably 5/95 to 25/75, Particularly preferred is 7/93 to 20/80. When the weight ratio of (i) is less than 5%, the hot offset resistance is deteriorated, and it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability.

  The peak molecular weight of (ii) is usually 1000 to 10,000, preferably 2000 to 8000, and more preferably 2000 to 5000. If it is less than 1000, heat-resistant storage stability will deteriorate, and if it exceeds 10,000, low-temperature fixability will deteriorate. The hydroxyl value of (ii) is preferably 5 or more, more preferably 10 to 120, and particularly preferably 20 to 80. If it is less than 5, it is disadvantageous in terms of both heat-resistant storage stability and low-temperature fixability. The acid value of (ii) is preferably 1 to 5, more preferably 2 to 4. Since a high acid value wax is used as the wax, the low acid value binder leads to electrification and high volume resistance, so that it is easy to match the toner used for the two-component developer.

The glass transition point (Tg) of the binder resin is usually 35 to 70 ° C, preferably 55 to 65 ° C. If the temperature is lower than 35 ° C., the heat-resistant storage stability of the toner is deteriorated. Since the urea-modified polyester is likely to be present on the surface of the obtained toner base particles, the toner of the present invention tends to have good heat storage stability even when the glass transition point is low, as compared with known polyester-based toners. Show.
The glass transition point (Tg) can be measured with a differential scanning calorimeter (DSC).

(Coloring agent)
As the colorant, all known dyes and pigments can be used. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ocher , Yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), Tartrazine Lake, Quinoline Yellow Lake, Anthrazan Yellow BGL, Isoindolinone Yellow, Bengala, Red Dan, Lead Zhu, Cadmium Red, Cadmium Mercury Red, Antimon Zhu, Permanent Red 4R, Para Red, Phi Sayred, Parachlor Ortonito Aniline Red, Resol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine B, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Resol Rubin GX, Permanent Red F5R , Brilliant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thio Indigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red Polyazo Red, Chrome Vermillion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal Free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), indigo, ultramarine blue, bitumen, anthraquinone blue, fast violet B, methyl violet lake, cobalt purple, manganese purple, dioxane violet, anthraquinone violet, chrome green, zinc green, chromium oxide, pyridian, emerald green, pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake, Malachite Green Lake, Lid Russian nin green, anthraquinone green, titanium oxide, zinc white, litbon and mixtures thereof can be used. The content of the colorant is usually 1 to 15% by weight, preferably 3 to 10% by weight, based on the toner.

  The colorant can also be used as a master batch combined with a resin. As a binder resin to be kneaded with the production of the master batch or the master batch, a polymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyl toluene or the like, or a copolymer of these and a vinyl compound, Polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, fat Aromatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be mentioned, and these can be used alone or in combination.

(Charge control agent)
Known charge control agents can be used, such as nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (fluorine-modified 4 Secondary ammonium salts or compounds, tungsten simple substances or compounds, fluorine activators, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, Bontron 03 of a nigrosine dye, Bontron P-51 of a quaternary ammonium salt, Bontron S-34 of a metal-containing azo dye, E-82 of an oxynaphthoic acid metal complex, E-84 of a salicylic acid metal complex , Phenolic condensate E-89 (above, Orient Chemical Industries, Ltd.), quaternary ammonium salt molybdenum complex TP-302, TP-415 (above, Hodogaya Chemical Co., Ltd.), quaternary ammonium salt copy Charge PSY VP2038, copy blue PR of triphenylmethane derivative, copy charge of quaternary ammonium salt NEG VP2036, copy charge NX VP434 (manufactured by Hoechst), LRA-901, LR-147 which is a boron complex (Nippon Carlit) Manufactured), copper phthalocyanine, perylene, quinacridone, azo series Fee, a sulfonic acid group, a carboxyl group, and polymer compounds having a functional group such as quaternary ammonium salts. Of these, substances that control the negative polarity of the toner are particularly preferably used.

  The amount of the charge control agent used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner production method including the dispersion method, and is not uniquely limited. Preferably, it is used in the range of 0.1 to 10 parts by weight with respect to 100 parts by weight of the binder resin. The range of 0.2 to 5 parts by weight is preferable. When the amount exceeds 10 parts by weight, the chargeability of the toner is too high, the effect of the charge control agent is reduced, the electrostatic attraction with the developing roller is increased, the flowability of the developer is lowered, and the image density is lowered. Invite.

(Release agent)
As a release agent, a low melting point wax having a melting point of 50 to 120 ° C. works more effectively as a release agent in the dispersion with the binder resin between the fixing roller and the toner interface. The effect on high temperature offset is exhibited without applying a release agent such as oil. Examples of such a wax component include the following. Examples of waxes and waxes include plant waxes such as carnauba wax, cotton wax, wood wax, rice wax, animal waxes such as beeswax and lanolin, mineral waxes such as ozokerite and cercin, and paraffin, microcrystalline, And petroleum waxes such as petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers can be used. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, chlorinated hydrocarbon, and low molecular weight crystalline polymer resin, poly-n-stearyl methacrylate, poly-n- A crystalline polymer having a long alkyl group in the side chain such as a homopolymer or copolymer of polyacrylate such as lauryl methacrylate (for example, a copolymer of n-stearyl acrylate-ethyl methacrylate, etc.) can also be used. .
The charge control agent and the release agent can be melt-kneaded together with the master batch and the binder resin, and of course, they may be added when dissolved and dispersed in the organic solvent.

(External additive)
Inorganic fine particles are preferably used as an external additive for assisting the fluidity, developability and chargeability of the toner particles. The primary particle diameter of the inorganic fine particles is preferably 5 × 10 −3 to 2 μm, and particularly preferably 5 × 10 −3 to 0.5 μm. Moreover, it is preferable that the specific surface area by BET method is 20-500 m <2> / g. The use ratio of the inorganic fine particles is preferably 0.01 to 5 wt% of the toner, and particularly preferably 0.01 to 2.0 wt%.

  Specific examples of the inorganic fine particles include, for example, silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, tin oxide, quartz sand, clay, mica, wollastonite, diatomaceous earth. Examples include soil, chromium oxide, cerium oxide, bengara, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, as the fluidity imparting agent, it is preferable to use hydrophobic silica fine particles and hydrophobic titanium oxide fine particles in combination. In particular, when stirring and mixing are performed using particles having an average particle size of 5 × 10-2 μm or less, the electrostatic force and van der Waals force with the toner are remarkably improved. Even when stirring and mixing inside the developing device is performed, a fluidity-imparting agent is not detached from the toner, a good image quality that does not cause fireflies and the like is obtained, and a reduction in residual toner is further achieved. .

  Titanium oxide fine particles are excellent in environmental stability and image density stability, but have a tendency to deteriorate the charge rise characteristics. Therefore, if the amount of titanium oxide fine particles added is larger than the amount of silica fine particles added, this side effect is affected. It can be considered large. However, when the added amount of the hydrophobic silica fine particles and the hydrophobic titanium oxide fine particles is in the range of 0.3 to 1.5 wt%, the charge rising characteristics are not greatly impaired, and the desired charge rising characteristics can be obtained, that is, repeated copying. Stable image quality can be obtained even if

Next, a toner manufacturing method will be described. Here, although a preferable manufacturing method is shown, it is not limited to this.
(Toner production method)
1) A toner material solution is prepared by dispersing a colorant, unmodified polyester, a polyester prepolymer having an isocyanate group, and a release agent in an organic solvent.
The organic solvent is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal after toner base particle formation. Specifically, toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, Methyl isobutyl ketone and the like can be used alone or in combination of two or more. In particular, aromatic solvents such as toluene and xylene and halogenated hydrocarbons such as methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferable. The usage-amount of an organic solvent is 0-300 weight part normally with respect to 100 weight part of polyester prepolymers, Preferably it is 0-100 weight part, More preferably, it is 25-70 weight part.

2) The toner material liquid is emulsified in an aqueous medium in the presence of a surfactant and resin fine particles.
The aqueous medium may be water alone or an organic solvent such as alcohol (methanol, isopropyl alcohol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.). It may be included.

The amount of the aqueous medium used relative to 100 parts by weight of the toner material liquid is usually 50 to 2000 parts by weight, preferably 100 to 1000 parts by weight. If the amount is less than 50 parts by weight, the dispersion state of the toner material liquid is poor, and toner particles having a predetermined particle diameter cannot be obtained. If it exceeds 2000 parts by weight, it is not economical.
Further, in order to improve the dispersion in the aqueous medium, a dispersant such as a surfactant and resin fine particles is appropriately added.

  As surfactants, anionic surfactants such as alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, alkylamine salts, amino alcohol fatty acid derivatives, polyamine fatty acid derivatives, amine salt types such as imidazoline, Quaternary ammonium salt type cationic surfactants such as alkyltrimethylammonium salts, dialkyldimethylammonium salts, alkyldimethylbenzylammonium salts, pyridinium salts, alkylisoquinolinium salts, benzethonium chloride, fatty acid amide derivatives, polyhydric alcohols Nonionic surfactants such as derivatives, for example, amphoteric surfactants such as alanine, dodecyldi (aminoethyl) glycine, di (octylaminoethyl) glycine and N-alkyl-N, N-dimethylammonium betaine And the like.

  Further, by using a surfactant having a fluoroalkyl group, the effect can be obtained in a very small amount. Preferred anionic surfactants having a fluoroalkyl group include fluoroalkyl carboxylic acids having 2 to 10 carbon atoms and metal salts thereof, disodium perfluorooctanesulfonyl glutamate, 3- [ω-fluoroalkyl (C6-C11 ) Oxy] -1-alkyl (C3-C4) sodium sulfonate, 3- [ω-fluoroalkanoyl (C6-C8) -N-ethylamino] -1-propanesulfonic acid sodium, fluoroalkyl (C11-C20) carvone Acids and metal salts, perfluoroalkylcarboxylic acids (C7 to C13) and metal salts thereof, perfluoroalkyl (C4 to C12) sulfonic acids and metal salts thereof, perfluorooctanesulfonic acid diethanolamide, N-propyl-N- ( 2-Hydroxyethyl) Perful Olooctanesulfonamide, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt, perfluoroalkyl (C6-C10) -N-ethylsulfonylglycine salt, monoperfluoroalkyl (C6-C16) ethyl phosphate, etc. Can be mentioned.

  Product names include Surflon S-111, S-112, S-113 (Asahi Glass Co., Ltd.), Florard FC-93, FC-95, FC-98, FC-129 (Sumitomo 3M Co., Ltd.), Unidyne DS-101. DS-102 (manufactured by Daikin Industries, Ltd.), Megafac F-110, F-120, F-113, F-191, F-812, F-833 (manufactured by Dainippon Ink, Inc.), Xtop EF-102, 103, 104, 105, 112, 123A, 123B, 306A, 501, 201, 204 (manufactured by Tochem Products), and Fgentent F-100, F150 (manufactured by Neos).

  Moreover, as the cationic surfactant, aliphatic quaternary ammonium such as aliphatic primary, secondary or secondary amic acid, perfluoroalkyl (C6-C10) sulfonamidopropyltrimethylammonium salt which has a right fluoroalkyl group is used. Salt, benzalkonium salt, benzethonium chloride, pyridinium salt, imidazolinium salt, trade names include Surflon S-121 (manufactured by Asahi Glass), Florard FC-135 (manufactured by Sumitomo 3M), Unidyne DS-202 (Daikin Industries) Smoke), Megafac F-150, F-824 (Dainippon Ink Co., Ltd.), Xtop EF-132 (Tochem Products), Footage F-300 (Neos), and the like.

The resin fine particles are added to stabilize the toner base particles formed in the aqueous medium. For this reason, it is preferable to add so that the coverage existing on the surface of the toner base particles is in the range of 10 to 90%. For example, polymethyl methacrylate fine particles 1 μm and 3 μm, polystyrene fine particles 0.5 μm and 2 μm, poly (styrene-acrylonitrile) fine particles 1 μm, trade names are PB-200H (manufactured by Kao Corporation), SGP (manufactured by Soken Co., Ltd.), Techno Examples include polymer SB (manufactured by Sekisui Chemical Co., Ltd.), SGP-3G (manufactured by Sokensha), and micropearl (manufactured by Sekisui Fine Chemical Co., Ltd.).
In addition, inorganic compound dispersants such as tricalcium phosphate, calcium carbonate, titanium oxide, colloidal silica, and hydroxyapatite can also be used.

  As a dispersant that can be used in combination with the above resin fine particles and inorganic compound dispersant, the dispersed droplets may be stabilized by a polymer protective colloid. For example, acrylic acid, methacrylic acid, α-cyanoacrylic acid, α-cyanomethacrylic acid, itaconic acid, crotonic acid, fumaric acid, maleic acid or maleic anhydride and other (meth) acrylic monomers containing hydroxyl groups Bodies such as acrylic acid-β-hydroxyethyl, methacrylic acid-β-hydroxyethyl, acrylic acid-β-hydroxypropyl, methacrylic acid-β-hydroxypropyl, acrylic acid-γ-hydroxypropyl, methacrylic acid-γ-hydroxy Propyl, acrylic acid-3-chloro-2-hydroxypropyl, methacrylic acid-3-chloro-2-hydroxypropyl, diethylene glycol monoacrylate, diethylene glycol monomethacrylate, glycerol monoacrylate, glycerol monomethacrylate Luric acid esters, N-methylol acrylamide, N-methylol methacrylamide, etc., vinyl alcohol or ethers with vinyl alcohol, such as vinyl methyl ether, vinyl ethyl ether, vinyl propyl ether, or compounds containing vinyl alcohol and a carboxyl group Esters such as vinyl acetate, vinyl propionate, vinyl butyrate, acrylamide, methacrylamide, diacetone acrylamide or their methylol compounds, acid chlorides such as acrylic acid chloride, methacrylic acid chloride, vinyl pyridine, vinyl pyrrolidone, vinyl Nitrogen compounds such as imidazole and ethyleneimine, or homopolymers or copolymers such as those having a heterocyclic ring thereof, polyoxyethylene, poly Xoxypropylene, polyoxyethylene alkylamine, polyoxypropylene alkylamine, polyoxyethylene alkylamide, polyoxypropylene alkylamide, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl phenyl ether, polyoxyethylene stearyl phenyl ester, polyoxy Polyoxyethylenes such as ethylene nonylphenyl ester, celluloses such as methyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose can be used.

  The dispersion method is not particularly limited, and known equipment such as a low-speed shear method, a high-speed shear method, a friction method, a high-pressure jet method, and an ultrasonic wave can be applied. Among these, the high-speed shearing method is preferable in order to make the particle size of the dispersion 2 to 20 μm. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1000 to 30000 rpm, preferably 5000 to 20000 rpm. The dispersion time is not particularly limited, but in the case of a batch method, it is usually 0.1 to 5 minutes. The temperature during dispersion is usually 0 to 150 ° C. (under pressure), preferably 40 to 98 ° C.

3) At the same time as the preparation of the emulsion, the amines (B) are added to cause a reaction with the polyester prepolymer (A) having an isocyanate group.
This reaction involves molecular chain crosslinking and / or elongation. The reaction time is selected depending on the reactivity of the isocyanate group structure of the polyester prepolymer (A) with the amines (B), but is usually 10 minutes to 40 hours, preferably 2 to 24 hours. The reaction temperature is generally 0 to 150 ° C, preferably 40 to 98 ° C. Moreover, a well-known catalyst can be used as needed. Specific examples include dibutyltin laurate and dioctyltin laurate.

4) After completion of the reaction, the organic solvent is removed from the emulsified dispersion (reactant), washed and dried to obtain toner base particles.
In order to remove the organic solvent, the temperature of the entire system is gradually raised in a laminar stirring state, and after giving strong stirring in a certain temperature range, the solvent base is removed to produce spindle-shaped toner base particles. . Further, when an acid such as calcium phosphate salt or an alkali-soluble material is used as the dispersion stabilizer, the calcium phosphate salt is dissolved from the toner base particles by a method such as dissolving the calcium phosphate salt with an acid such as hydrochloric acid and washing with water. Remove. It can also be removed by operations such as enzymatic degradation.

5) A charge control agent is injected into the toner base particles obtained above, and then inorganic fine particles such as silica fine particles and titanium oxide fine particles are externally added to obtain a toner.
The injection of the charge control agent and the external addition of the inorganic fine particles are performed by a known method using a mixer or the like.

  Thereby, a toner having a small particle size and a sharp particle size distribution can be easily obtained. Furthermore, by giving strong agitation in the process of removing the organic solvent, the shape between the true spherical shape and the rugby ball shape can be controlled, and the surface morphology is also controlled between the smooth shape and the umeboshi shape. be able to.

The shape of the toner is substantially spherical, and is represented by the following shape rule.
FIG. 4 is a diagram schematically showing the shape of the toner. In FIG. 4, when a substantially spherical toner is defined by a major axis length r1, a minor axis length r2, and a thickness r3 (where r1 ≧ r2 ≧ r3), the toner has a minor axis length. The ratio (r2 / r1) of the length (r2) to the length (r1) of the long axis (see FIG. 4 (b)) is 0.5 or more and 1.0 or less, and the thickness (r3) and the short axis The ratio (r3 / r2) to the length (r2) (see FIG. 4C) is preferably in the range of 0.7 to 1.0. When the ratio (r2 / r1) of the length of the short axis (r2) to the length of the long axis (r1) is less than 0.5, the dot reproducibility and transfer efficiency are inferior due to the separation from the true spherical shape, resulting in high quality. Image quality is not obtained. If the ratio (r3 / r2) between the thickness (r3) and the short axis length (r2) is less than 0.7, the shape is nearly flat, and a high transfer rate like a spherical toner cannot be obtained. In particular, when the ratio (r3 / r2) of the thickness (r3) to the length (r2) of the minor axis is 1.0, a rotating body having the major axis as the rotation axis is obtained, and the fluidity of the toner is improved.

Note that r1, r2, and r3 were measured with a scanning electron microscope (SEM) while changing the angle of field of view and taking pictures.
The above toner can also be used as a one-component magnetic toner that does not use a magnetic carrier or a non-magnetic toner.

  Details of the configuration and functions of the cleaning blade 78Y, the coating blade 45Y, the partition wall 57, the discharge screw 58Y, and the like, and the functions of the coating device 40Y and the cleaning device 70Y related thereto will be described.

  As already described, in the configuration provided with the coating blade 45Y, if the protective agent 42Y is not supplied to the photosensitive drum 20Y sufficiently and stably, in addition to the chatter vibration of the coating blade 45Y and the abnormal noise caused by turning over, the coating is applied. There is a possibility that the function of the coating blade 45Y may not be sufficiently exhibited due to abnormal wear or cracking of the blade 45Y. On the other hand, when the residual toner exists at a position where the coating blade 45Y contacts the photosensitive drum 20Y, the inventors prevent or suppress chatter vibration and inversion of the coating blade 45Y. As described above, it has been found that abnormal wear and cracks are prevented or suppressed and the function of the coating blade 45Y is satisfactorily exhibited over time.

  Therefore, in the cleaning device 70Y, in order to make the residual toner exist at a position where the coating blade 45Y contacts the photosensitive drum 20Y, as shown in FIG. 5, the longitudinal direction of the photosensitive drum 20Y of the cleaning blade 78Y. The ridgeline portion 78aY that is in contact with the photoconductive drum 20Y extending in the direction of the cross section has an obtuse angle θ on the cross section of a plane perpendicular to the longitudinal direction, that is, a plane parallel to the paper surface of FIGS.

  Thus, a wedge-shaped space is formed between the cleaning blade 78Y and the photosensitive drum 20Y on the upstream side in the B1 direction from the ridgeline portion 78aY. The residual toner on the photosensitive drum 20Y scraped off by the cleaning blade 78Y stays in the wedge-shaped space and aggregates due to the wedge effect in which the residual toner is pushed toward the ridgeline portion 78aY in the wedge-shaped space. , Some slip-through occurs. Part of the residual toner that has passed through the ridgeline 78aY is scraped and restrained by the brush roller 47Y, but a part of the residual toner reaches the position where the coating blade 45Y contacts the photoreceptor drum 20Y and is supplied. This prevents or suppresses chatter vibration and reversal of the coating blade 45Y, thereby preventing or suppressing abnormal noise, abnormal wear, and cracking, so that the function of the coating blade 45Y is satisfactorily exhibited over time.

  The amount of residual toner that is supplied when the coating blade 45Y comes into contact with the photosensitive drum 20Y is very small, and the coating blade 45Y also has a function of scraping the residual toner on the photosensitive drum 20Y. Accordingly, the residual toner supplied to the position where the coating blade 45Y contacts the photosensitive drum 20Y does not slip through the position, and the charging device 90Y is not contaminated or the image is not affected.

  As described above, since the coating blade 45Y is in counter contact with the photosensitive drum 20Y, functions such as a uniforming action of the protective agent 42Y are higher than in the trailing contact. However, problems such as chatter vibration and inversion are more likely to occur in counter contact than in trailing contact. However, such a problem is prevented or suppressed by the application blade 45Y reaching the position where it contacts the photosensitive drum 20Y and the residual toner is supplied, and the function of preventing the residual toner from slipping through the counter contact is high. It is possible to prevent the 90Y from being contaminated or affecting the image.

  Further, regarding the amount of foreign matter such as residual toner adhering to the brush roller 47Y, the foreign matter on the photosensitive drum 20Y is sufficiently cleaned by the cleaning device 70Y, specifically, the brush roller 52Y and the cleaning blade 78Y. Such an amount does not affect the supply performance of the protective agent 42Y even over time so as to make it insufficient.

  Since the cleaning blade 78Y is in counter contact with the photosensitive drum 20Y as described above, the cleaning performance is higher than that of trailing contact. However, since the angle θ is an obtuse angle, the cleaning performance is slightly deteriorated compared to the case where the angle θ is a right angle, and the problem of chatter vibration and inversion occurs more than the trailing contact due to the counter contact. Cheap. However, a slight decrease in the cleaning performance is necessary for the residual toner to pass through, and the fact that the angle θ is an obtuse angle is useful for preventing or suppressing chatter vibration and inversion.

  When the angle θ is a right angle, it is possible to pass the residual toner by decreasing the contact pressure of the cleaning blade 78Y to the photosensitive drum 20Y. However, if the contact pressure is decreased, the cleaning blade 78Y is reduced. However, it is difficult to set and maintain the contact pressure appropriately since the cleaning state rapidly changes from a cleaning state to a state in which residual toner passes through frequently. Even if the contact pressure can be appropriately set and maintained, there are places where there are a lot of slipping through and a place where there is a lot of slipping due to unevenness and unevenness in hardness, repulsion male, Young's modulus, etc. in the cleaning blade 78Y. The brush roller 47Y is contaminated in a place where there are many slip-throughs, and the application function of the protective agent 42Y is deteriorated. This is because the wedge effect is insufficient when the angle θ is a right angle. Therefore, the angle θ needs to be an obtuse angle.

Here, the angle θ and the angles α and β shown in FIG. 5 will be described.
In addition to the angle θ, both the angles α and β are angles on a cross section of the same plane, that is, a plane orthogonal to the longitudinal direction of the photosensitive drum 20Y, that is, a plane parallel to the paper surface of FIGS. Angles α and β are respectively the upstream and downstream angles in the B1 direction between the tangent line of the photosensitive drum 20Y and the cleaning blade 78Y at the ridge line portion 78aY. Therefore, the angle α is an angle of the wedge-shaped space on the plane, and the angle β is an angle called a contact angle.

  In this embodiment, the angle β is set in a range of 10 degrees or more and 30 degrees or less, which is a general contact angle. The angle θ is set in the range of 95 degrees or more and less than 140 degrees, and the angle α is set in the range of more than 10 degrees and 75 degrees or less. Thereby, the wedge effect is exhibited satisfactorily.

  The application blade 45Y also has angles θ, α, and β similar to the angles θ, α, and β in the cleaning blade 78Y. In FIG. 5, reference numeral 45aY denotes a ridge line portion of the coating blade 45Y that extends in the longitudinal direction of the photosensitive drum 20Y and contacts the photosensitive drum 20Y.

  The angles θ, α, and β for the coating blade 45Y are the same as the angles θ, α, and β for the cleaning blade 78Y. The angle θ for the coating blade 45Y is an obtuse angle, so that even at the counter contact, the tip is difficult to turn, and chatter vibration and reversal are less likely to occur and the life is extended. These parts can be shared and the cost can be reduced. The angle β for the coating blade 45Y is also set in a range of 10 degrees to 30 degrees, which is a general contact angle, and the angle θ is set in a range of 95 degrees to less than 140 degrees, and the angle α Is set in the range of more than 10 degrees and 75 degrees or less. Thereby, suppression of chatter vibration and reversal and longer life are achieved to a higher degree. However, the angle θ may be approximately 90 degrees, and in this case, the manufacturing is easy and the cost can be reduced, and the intended functions such as the uniformizing function and the coating function of the protective agent 42Y are satisfactorily exhibited. Further, slipping of the residual toner can be prevented or suppressed more satisfactorily.

  The partition wall 57Y includes a partition member 57aY that blocks between the cleaning blade 78Y and the coating device 40Y, and a seal member 57bY that seals a gap between the partition member 57aY and the photosensitive drum 20Y.

  By having the partition wall 57Y, the residual toner or powdery protective agent 42Y scattered by the rotation of the brush roller 47Y dissipates to a portion other than the coating device 40Y, particularly a portion below the coating device 40Y in the cleaning device 70Y. The scattered residual toner and protective agent 42Y are received from below by the partition wall 57Y, and the received residual toner and protective agent 42Y are supplied to the photosensitive drum 20Y by the rotation of the brush roller 47Y. The supply efficiency and supply stability of the protective agent 42Y to the photosensitive drum 20Y are improved, and the supply efficiency and supply stability of the residual toner toward the coating blade 45Y are improved.

  In addition to this, the partition wall 57Y also has the following functions. However, if there is no partition wall 57Y, residual toner or powdery protective agent 42Y scattered by the rotation of the brush roller 47Y accumulates on the cleaning blade 78Y and aggregates to form aggregates. Filming that is pressed onto the surface of the photoreceptor drum 20Y to form a film on the surface may occur, which may affect image formation. Also, the aggregates collapse and the photoreceptor drum 20Y rotates. When reaching the brush roller 47Y or the coating blade 45Y, there is a possibility that the supply of the protective agent 42Y may be poor or the slipping from the coating blade 45Y may occur, which may affect image formation such as the generation of streak images. However, if the partition wall 57Y is provided, the protective agent 42Y such as residual toner or powder scattered by the rotation of the brush roller 47Y is provided. Without having to deposit between the leaning blade 78Y and the brush roller 47Y, the this occurs is prevented.

  The partition member 57aY is fixed to the cleaning case 71Y by bonding at the end opposite to the side facing the photosensitive drum 20Y. The end side of the partition wall member 57aY has a concave shape that protrudes downward, and has a storage portion 57cY that can store foreign particles such as residual toner and powdery protective agent 42Y scattered by the rotation of the brush roller 47Y. Forming. The discharge screw 58Y is disposed in the storage portion 57cY and discharges such foreign matter that has accumulated in the storage portion 57cY. Thereby, the above-described function of the partition wall 57Y is satisfactorily exhibited.

  Note that the discharge screw 58Y may be omitted when the amount of foreign matter stored in the storage unit 57cY is sufficient for the life of the protective agent 42Y and the process cartridge 68Y. Further, when the partition wall 57Y is configured to be inclined so that the brush roller 47Y side is downward, the protective agent 42Y, such as residual toner and powder, scattered by the rotation of the brush roller 47Y is sequentially brushed by the inclination. If the roller 47Y reaches the roller 47Y and is supplied to and consumed by the photosensitive drum 20Y by the rotation of the brush roller 47Y, such agglomerates will not occur. Therefore, even if such a configuration is adopted and the reservoir 57cY is omitted. good.

  The seal member 57bY is an elastic body formed of a film or rubber having a low surface friction, and is elastically in contact with the surface of the photosensitive drum 20Y so that the tip thereof is directed in the B1 direction, and is applied to the cleaning blade 78Y. In addition to improving the shielding property with respect to the apparatus 40Y, the residual toner that has passed through the cleaning blade 78Y is not prevented from moving toward the brush roller 47Y. However, the seal member 57bY may be omitted if the partition member 57aY sufficiently blocks the cleaning blade 78Y and the coating device 40Y.

  The operation and the like of the image forming apparatus 100 configured as described above will be described. In the image forming unit 60Y provided in the image forming apparatus 100, an image is formed by a negative-positive process.

  The surface of the photosensitive drum 20Y is negatively charged uniformly by the charging device 90Y as it rotates in the B1 direction. Since a protective layer is formed on the photosensitive drum 20Y, stress during charging is reduced.

  An electrostatic latent image corresponding to yellow is formed by exposure scanning of the laser beam L from the optical scanning device 8. At this time, the scanning direction of exposure is the rotational axis direction of the photosensitive drum 20Y, and the absolute value of the exposed portion potential is lower than the absolute value of the non-exposed portion potential.

This electrostatic latent image is developed with the yellow toner in the developer by the developing device 80Y, and the yellow toner image obtained by the development is primarily transferred to the transfer belt 11 that moves in the A1 direction by the primary transfer roller 12Y. The residual toner that has been transferred and remains after the transfer is removed by the cleaning device 70Y. Since the protective agent 42Y is uniformly applied to the photosensitive drum 20Y to form a protective layer, the stress during cleaning is reduced and the cleaning is performed well. Since an appropriate amount of residual toner is supplied to the coating blade 45Y, chatter vibration and reversal are prevented or suppressed over time, and the protective agent 42Y is satisfactorily applied to the photosensitive drum 20Y over time, and the function of the protective agent 42Y is improved. Good performance over time.
Next, the residual charge is removed by the static eliminator and used for the next static elimination and charging by the charging device 90Y.

  Similarly, toner images of the respective colors are formed on the other photosensitive drums 20M, 20C, and 20BK, and the formed toner images of the respective colors are transferred to the A1 direction by the primary transfer rollers 12M, 12C, and 12BK. 11 is sequentially transferred to the same position on the head. As the transfer belt 11 rotates in the A1 direction, the toner image superimposed on the transfer belt 11 moves to the secondary transfer nip, which is a position facing the secondary transfer belt 5, and adheres closely to the transfer paper. Secondary transfer is performed on the transfer paper by the action of the transfer bias and nip pressure, and a full-color image is formed on the transfer paper.

The transfer paper conveyed between the transfer belt 11 and the secondary transfer belt 5 is fed out and fed from the sheet feeding device 61 by the feeding roller 3 and is fed by the registration roller 4 based on a detection signal from the sensor. The leading edge of the toner image on the transfer belt 11 is sent out at a timing facing the secondary transfer belt 5.
The secondary transfer belt 5 is applied with a potential having a polarity opposite to the polarity of toner charging from a power source.

  When the toner images of all colors are collectively transferred and carried on the transfer paper, the transfer paper is conveyed by the secondary transfer unit 76, specifically, by the rotation of the secondary transfer belt 5, and enters the fixing device 6 to be added. When passing through the fixing unit between the pressure roller 63 and the belt unit 62, the carried toner image is fixed by the action of heat and pressure, and the full color image is fixed on the transfer paper. The fixed transfer paper that has passed through the fixing device 6 passes through the paper discharge roller 7 and is stacked on the paper discharge tray 17 at the top of the main body 99. On the other hand, the surface of the transfer belt 11 after passing through the secondary transfer nip after the secondary transfer is cleaned by a cleaning brush and a cleaning blade provided in the cleaning device 13 to prepare for the next development process.

  Since each of the photosensitive drums 20Y, 20M, 20C, and 20BK is applied with a protective agent and functions well, the image formation is performed well over a long period of time.

  The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the specific embodiments, and the present invention described in the claims is not specifically limited by the above description. Various modifications and changes are possible within the scope of the above.

For example, the process cartridge needs to include at least the image carrier and the cleaning device and be detachable from the main body of the image forming apparatus. Selection of other components constituting the process cartridge includes the image carrier, This is performed as appropriate in consideration of the lifetime of the component, the cost, the ease of construction of the process cartridge, and the like.
The image carrier to which the image carrier protecting agent is supplied may be an intermediate transfer member such as the intermediate transfer belt 11 and may carry the transferred toner image.

  Similarly to a so-called tandem type image forming apparatus, a so-called one-drum type image forming apparatus that sequentially forms toner images of each color on a single photosensitive drum and sequentially superimposes the color toner images to obtain a color image. Can be applied. Further, the present invention can be applied not only to a color image forming apparatus but also to a monochrome image forming apparatus. In any type of image forming apparatus, a toner image of each color may be directly transferred onto a transfer sheet or the like without using an intermediate transfer member. In this case, for example, referring to FIG. 2, the transfer belt 11 corresponds to transfer paper.

  The effects described in the embodiments of the present invention are only the most preferable effects resulting from the present invention, and the effects of the present invention are limited to those described in the embodiments of the present invention. is not.

20Y, 20M, 20C, 20BK Image carrier 42Y Image carrier protective agent 43Y Blade constant load support means 45Y Image carrier protective agent uniformizing blade 45aY Edge of image carrier protective agent uniforming blade 49Y Image carrier protective agent uniform Converting means 56Y protective agent supplying means 57Y partition wall 68Y process cartridge 78Y cleaning blade 78aY ridge line portion of cleaning blade 100 image forming apparatus B1 moving direction of image carrier θ obtuse angle

Japanese Patent Laid-Open No. 11-184340 JP 2003-140518 A JP 2000-330443 A JP-A-2005-070276 JP-A-5-019671 JP 2004-272019 A

Claims (17)

A cleaning blade that extends in the longitudinal direction of the image carrier and has a ridge portion in contact with the image carrier, and for cleaning the image carrier;
Protective agent supplying means for supplying the image carrier with an image carrier protective agent for protecting the image carrier downstream of the position where the cleaning blade is in contact with the image carrier in the moving direction of the image carrier; ,
On the surface of the image carrier, the image carrier protective agent supplied to the image carrier downstream of the position where the image carrier protective agent is supplied to the image carrier by the protective agent supply means in the moving direction. Image carrier protective agent homogenizing means for homogenizing,
One end is disposed in contact with the image carrier so as to shield between the cleaning blade and the protective agent supply means, and the end opposite to the one end is disposed on the case. A fixed partition that forms a reservoir for collecting foreign matter scattered from the protective material supply means ;
A discharge screw for discharging the foreign matter from the reservoir ,
The ridge line portion of the cleaning blade is a cleaning device in which an angle on a cross section by a plane orthogonal to the longitudinal direction is an obtuse angle. The cleaning device according to claim 1.
The cleaning device, wherein the obtuse angle of the cleaning blade is 95 degrees or more and less than 140 degrees . The cleaning device according to claim 1 or 2,
The image carrier protective agent homogenizing means has an image carrier protective agent uniformizing blade extending in the longitudinal direction of the image carrier and having a ridge line portion in contact with the image carrier. . The cleaning device according to claim 3 .
The cleaning device according to claim 1, wherein the ridge portion of the image carrier protective agent uniformizing blade has an obtuse angle on a cross section by a plane orthogonal to the longitudinal direction . The cleaning device according to claim 4.
The cleaning apparatus , wherein the obtuse angle of the image carrier protective agent uniformizing blade is 95 degrees or more and less than 140 degrees . The cleaning device according to claim 3 .
The cleaning device according to claim 1, wherein the ridge line portion of the image carrier protective agent uniformizing blade has an angle on a cross section of a plane orthogonal to the longitudinal direction of approximately 90 degrees . The cleaning device according to any one of claims 3 to 6 ,
The cleaning apparatus according to claim 1 , wherein the image carrier protective agent uniformizing blade is in counter contact with the image carrier . The cleaning device according to any one of claims 3 to 7 ,
The cleaning apparatus according to claim 1, wherein the image carrier protective agent uniformizing means includes blade fixing support means for fixing and supporting the image carrier protective agent uniforming blade . The cleaning device according to any one of claims 3 to 7 ,
The image carrier protecting agent uniformizing means is a blade constant load supporting means for supporting the image carrier protecting agent uniformizing blade and bringing the image carrier protecting agent uniformizing blade into contact with the image carrier with a constant load. cleaning apparatus characterized by having a. A process cartridge having the cleaning device according to claim 1 . The cleaning device according to any one of claims 1 to 9, or an image forming apparatus having a process cartridge according to claim 10, wherein. The image forming apparatus according to claim 11.
  An image forming apparatus using a toner having a circularity of 0.92 or more. The image forming apparatus according to claim 11 or 12,
An image forming apparatus using a toner having a shape factor SF-1 in a range of 100 to 180 and a shape factor SF-2 in a range of 100 to 180 . The image forming apparatus according to any one of claims 4 to 7,
The volume average particle diameter (Dv) is in the range of 3 μm or more and 8 μm or less, and the dispersity defined by the ratio (Dv / Dn) of the volume average particle diameter (Dv) to the number average particle diameter (Dn) is 1. An image forming apparatus using a toner in a range from 05 to 1.40 . The image forming apparatus according to any one of claims 11 to 14,
The ratio (r2 / r1) of the length of the minor axis (r2) to the length of the major axis (r1) is in the range of 0.5 to 1.0,
The ratio (r3 / r2) of the thickness (r3) to the length (r2) of the minor axis is in the range of 0.7 to 1.0,
An image forming apparatus comprising: a toner satisfying a relationship of a length of the major axis (r1) ≧ a length of the minor axis (r2) ≧ the thickness (r3) . The image forming apparatus according to any one of claims 12 to 15,
The toner is
A polyester polymer having a functional group containing a nitrogen atom;
With polyester,
A colorant;
With release agent
An image forming apparatus , wherein the toner composition is formed by crosslinking and / or stretching reaction in the presence of resin fine particles in an aqueous medium . An image is formed using the cleaning device according to any one of claims 1 to 9, the process cartridge according to claim 10, or the image forming device according to any one of claims 11 to 16. An image forming method to be performed.

Images