JP2007333788A - Lubricant application device, process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably and uniformly apply a lubricant to the surface of an image carrier over a long period of time. <P>SOLUTION: The lubricant application device 11 includes: a lubricant 7; a lubricant application brush roller 6 for applying the lubricant to the surface of a photoreceptor 2 while rotating; and a spring 9, serving as a lubricant pressing means, which presses the lubricant against the lubricant application brush roller. The lubricant application device 11 scrapes the lubricant by use of the lubricant application brush roller, thereby applying it to the surface of the photoreceptor 2. The lubricant application device 11 further includes a spring 10 movable in the direction in which the lubricant application roller is brought into contact with the photoreceptor 2 and separated therefrom, and serving as a brush roller pressing means for pressing the lubricant application brush roller against the photoreceptor 2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a lubricant application device that applies a lubricant to an image carrier, and a process cartridge and an image forming apparatus that employ such a lubricant application device.

  Conventionally, an inorganic photoconductor produced by vacuum deposition of a selenium film has been used as a photoconductor for an electrophotographic image forming apparatus. However, the cost is lower than that of an inorganic photoconductor, and there is almost no toxicity. Organic photoconductors having advantages such as easy film properties are increasingly used. However, organophotoreceptors are prone to film scraping due to repeated use, and when film scraping progresses, due to a decrease in the charge potential of the photoreceptor, deterioration of photosensitivity, scratches on the surface of the photoreceptor, etc. Deterioration will occur. Furthermore, in recent years, improvement in durability has become indispensable for organic photoreceptors due to the increase in the speed of image forming apparatuses, the reduction in diameter of the photoreceptors accompanying the downsizing of the apparatus due to full color, and maintenance-free movement. Yes.

  Among organic photoconductors, the mainstream is a laminated type in which a so-called charge generation layer and charge transport layer are laminated on a conductive substrate. However, in a laminated type organic photoconductor, various substances are added to the charge transport layer. By doing so, physical properties of the surface of the photoreceptor are improved, and mechanical durability (abrasion resistance) is improved.

  However, as the mechanical durability (wear resistance) of the photoconductor is improved, a side effect that image blur is likely to occur has occurred. This is because ozone and NOx gas generated when charging the photosensitive member, and ion species (hereinafter referred to as a charged product) generated by these and moisture in the atmosphere adhere and deposit on the photosensitive member. This is because, by reducing the surface resistance of the photosensitive member, the lateral movement of charges occurs and the electrostatic latent image becomes blurred. In the conventional photoconductor having low mechanical durability (wear resistance), even if the charged product is deposited on the surface of the photoconductor, it is removed by abrasion, and image blur is not a serious problem. In contrast, with a photoconductor with improved mechanical durability (wear resistance), once scratches occur on the surface of the photoconductor, the generated scratches are difficult to remove, and charged products are deposited and removed on the scratched portions. This is thought to be difficult.

  In addition, as the mechanical durability (abrasion resistance) of the photoconductor is improved, the number of times the photoconductor can be used repeatedly can be increased. However, the time and the number of times the photoconductor surface is exposed to a hazard such as charging as the increase increases. Increase dramatically. For this reason, the surface material of the photoconductor is ionized by the hazard, and further, the bond is broken and the quality is changed. In this case, even if the image blur does not occur, a local resistance decrease occurs, causing dot enlargement and gradation deterioration under high temperature and high humidity. The effect of the photoconductor surface property on image quality becomes greater as higher image quality is required, and it is not sufficient to simply increase the mechanical durability of the photoconductor. It has been a major challenge to improve the so-called high image quality durability of the photoreceptor so that the image quality deterioration due to hazards can be avoided and high image quality can be maintained.

  On the other hand, studies on charging means for reducing charged products have also been made. As a charging means for the photosensitive member, in a contact charging method such as a charging roller or a charging brush, since the charging member is in contact with the photosensitive member, it can be charged with a low applied voltage, and the generation amount of the charged product is small. It is greatly reduced. Therefore, it has an advantage over image blur and is superior in the uniformity of charging compared to corona charging, and can be said to be an advantageous method for high image quality and high durability of image quality. . However, in the contact charging method, since the charging member and the photoconductor are in direct contact with each other in the image forming region, toner and foreign matter adhere to the charging member and are contaminated. For this reason, defects such as deterioration of charging property, contamination of the photoreceptor due to re-adhering of contaminants from the charging member, and acceleration of uneven wear or wear of the photoreceptor due to contamination of the charging member are likely to occur. In addition, since the charging member and the photosensitive member are in direct contact with each other, the removal efficiency of the foreign matter on the surface of the photosensitive member is reduced, and the charging roller trace remains on the photosensitive member or deformation of the charging roller causes an abnormal image. May occur.

  In view of this, an increasing number of devices adopting a proximity charging method in which a charging member is disposed in proximity to a photoconductor. In the proximity charging method, it is possible to reduce the generation amount of the chargeable organisms, and it is possible to reduce the above problem because the charging member and the photosensitive member are not in direct contact in the image forming area. It is a particularly effective method for high durability and high image quality. However, in the proximity charging system, the accuracy of the gap is a problem in arranging the charging member and the photosensitive member in proximity, and there has been a tendency that the charging stability is somewhat lowered. In order to improve the charging stability, the problem can be solved by superimposing the AC component on the DC component. However, this increases the generation amount of the charged product and easily causes image blurring. In addition, by disposing the charging member close to the photoconductor, discharge damage on the surface of the photoconductor is more likely to occur and appears as an abnormal image, thereby reducing the effects of image blur and discharge damage on the surface of the photoconductor. On the contrary, the effect is rather increasing, and the actual situation is that a sufficient effect has not been obtained for the enhancement of high image quality.

  As described above, in order to realize an image forming apparatus that achieves various requirements such as high image quality and downsizing, long life of the photoconductor, and energy saving, the mechanical durability (wear resistance) of the photoconductor is required. At the same time, it is indispensable to improve the high image quality durability of the photoreceptor by suppressing the occurrence of image blur and the like.

  Various methods for providing a lubricant application device for applying a lubricant to a photoconductor have been proposed as one method for improving the high image quality durability of the photoconductor by preventing the adhesion of charged products and suppressing the influence of hazards. (For example, patent document 1). The lubricant application device applies a lubricant to the photoconductor to lower the coefficient of friction of the photoconductor surface, thereby suppressing foreign matter adhesion and image blurring, as well as reducing the effects of charging hazards. It is important for improving the high image quality durability of the photoreceptor.

  Lubricant coating device uses a pressing means such as a spring to bring a solid lubricant composed of a fatty acid compound such as zinc stearate into pressure contact with a brush roller with good polishing and coating properties, and in the vicinity of the tip of the brush roller Scrap and hold. Further, the brush roller is fixed at a position where the vicinity of the brush tip rotates by rubbing the surface of the photoconductor, and applies a lubricant held by rubbing the surface of the photoconductor to the surface of the photoconductor. However, in this lubricant application device, since the solid lubricant is pressed against the brush roller by the spring, the brush roller tends to fall over time. When the brush falls, it appears to be the same state as when the outer diameter of the brush roller is reduced, and the probability that the brush rubs on the photoreceptor is reduced. For this reason, the lubricant is applied in the form of a brush, resulting in insufficient application amount of the lubricant and uneven application.

  In order to solve the shortage of application amount over time, it is conceivable to increase the initial lubricant application amount by predicting the lack of lubricant application amount over time. It is inappropriate because it causes side effects.

  Further, in order to solve the shortage of application amount over time, Patent Document 2 proposes a device provided with a pressing force changing means for changing the pressing force of a spring that presses and biases the lubricant to the brush roller. In this image forming apparatus, when the application amount becomes insufficient over time, the spring pressure is made variable so that the amount of wear of the lubricant is increased to compensate for the lack of lubricant application amount.

JP 2005-92109 A JP-A-2005-321833

  However, in the above-described method of increasing the amount of lubricant scraping to compensate for the insufficient amount of lubricant applied, the contact state between the brush roller and the photoreceptor that has fallen down does not change, so the probability of rubbing on the photoreceptor remains low. Although the insufficient amount of the lubricant applied can be improved, the uneven coating cannot be sufficiently improved. Therefore, it is desirable to find a method for applying a uniform and stable amount of lubricant over a long period of time even if the brush roller falls.

  The present invention has been made in view of the above background, a lubricant application device capable of stably and uniformly applying a lubricant over a long period of time on the surface of an image carrier, and a process cartridge employing the lubricant application device, An image forming apparatus is provided.

In order to achieve the above object, a first aspect of the present invention is directed to a lubricant, a lubricant application brush roller that applies the lubricant to the surface of the image carrier while being rotated, and the lubricant applied to the lubricant application brush. A lubricant pressurizing means for pressing and urging the roller, and the lubricant applying brush roller scrapes the lubricant with the lubricant applying brush roller and applies it to the surface of the image carrier. A brush roller pressurizing unit is provided which is movable in a direction in which the image bearing member is brought into contact with and separated from the image carrier and presses the lubricant application brush roller against the image carrier.
According to a second aspect of the present invention, there is provided the lubricant applying apparatus according to the first aspect, wherein the amount of biting of the lubricant applying brush roller between the surface of the image carrier and the amount of biting into the surface of the image carrier is restricted. A member is provided, and the amount of biting into the surface of the image carrier by the lubricant application brush roller is variable over time when the biting amount suppression member is worn over time due to contact with the surface of the image carrier. It is characterized by that.
Further, the invention of claim 3 comprises at least an electrostatic latent image carrier formed by curing the outermost layer, a non-contact type charging means disposed in proximity to the surface of the electrostatic latent image carrier, 3. A process cartridge according to claim 1, wherein a lubricant and a lubricant applying means for applying the lubricant are integrally formed on the surface of the electrostatic latent image bearing member and detachable from the main body of the image forming apparatus. The present invention is characterized in that an agent coating device is employed.
According to a fourth aspect of the present invention, in the process cartridge according to the third aspect, the lubricant application brush roller contacts and separates from the image carrier when its rotation center axis moves around a predetermined rotation axis. The direction of the force when the brush roller pressurizing means is pressed and urged so as to rotate the rotation center axis of the lubricant application brush roller in a direction in contact with the image carrier, The rotation center axis of the lubricant application brush roller and the rotation center axis of the electrostatic latent image carrier are configured to be substantially parallel to each other.
Further, the invention of claim 5 comprises at least an electrostatic latent image carrier formed by curing the outermost layer, a non-contact type charging means arranged in proximity to the surface of the electrostatic latent image carrier, Lubricant application means for applying a lubricant and a lubricant to the surface of the electrostatic latent image carrier and a cleaning blade that contacts the surface of the electrostatic latent image carrier and removes residual toner on the surface are formed integrally. In the process cartridge detachable from the forming apparatus main body, the cleaning blade has a function as a biting amount suppression member that regulates the biting amount of the lubricant application brush roller to the surface of the image carrier, and the cleaning blade has the image A feature is that the amount of biting of the lubricant-applying brush roller into the surface of the image carrier can be changed over time by being worn by contact with the surface of the carrier. It is intended.
According to a seventh aspect of the present invention, there is provided an electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the surface of the electrostatic latent image carrier, and the electrostatic latent image carrier. An image forming apparatus including a developing unit that develops an electrostatic latent image is characterized in that the process cartridge according to claim 3, 4 or 5 is adopted as a process cartridge removable from the image forming apparatus. .
The invention according to claim 8 is the image forming apparatus according to claim 6 or 7, wherein the lubricant application brush is rotated in a direction opposite to the direction in which the lubricant application brush roller is rotated during image formation during non-image formation. A mode for performing control is provided.

  In the first, second, third, fourth, fifth, sixth, seventh or eighth invention, the brush roller pressurizing means urges the lubricant-applying brush roller against the image carrier. Biting into the image carrier of the lubricant application brush roller can be maintained. In the conventional apparatus, the brush roller is fixed at a position where the vicinity of the brush tip appropriately bites into the surface of the image carrier and rubs and rotates on the surface of the image carrier in the early stage when no hair fall occurs. For this reason, when the hair falls, the lubricant application brush roller diameter is apparently reduced, the amount of biting is reduced, and the probability that the tip of the brush rubs the surface of the image carrier is reduced. There was a shortage. In the present invention, even when the hair fall occurs and the diameter of the lubricant application brush roller is apparently reduced, the brush roller pressurizing means moves the lubricant brush roller movable in the direction of contact with and away from the image carrier. Since the pressing force is applied to the body, the lubricant brush roller and the image carrier can be kept in a state where they are properly bitten. Therefore, even over time, the lubricant application brush roller can maintain the effect of rubbing the surface of the image carrier equivalent to that in the initial stage, and can apply the lubricant uniformly and stably over a long period of time.

  According to the first, second, third, fourth, fifth, sixth, seventh, or eighth inventions, there is an excellent effect that the lubricant can be stably and uniformly applied to the surface of the image carrier for a long time. is there.

  Hereinafter, an embodiment in which the present invention is applied to an electrophotographic image forming apparatus as an image forming apparatus will be described. FIG. 1 is a schematic configuration diagram of a main part of the image forming apparatus. In this image forming apparatus, a charging device 3, an exposure device (not shown), a developing device 5, a transfer device 12, and a cleaning device 4 are arranged around a drum-shaped photoconductor 2 as an electrostatic latent image carrier that rotates clockwise in the figure. Etc. In the charging device 3, a charging roller as a charging member is disposed close to the photoreceptor 2. The charging roller uniformly charges the surface of the photoreceptor 2 by applying a voltage in which an alternating current component is superimposed on a direct current component from a high voltage power supply for charging (not shown) connected to the rotating shaft. An exposure apparatus (not shown) irradiates the surface of the photoconductor 2 while scanning the surface of the photoconductor 2 based on the image data, thereby forming an electrostatic latent image on the surface of the photoconductor 2. The developing device 5 carries the accommodated developer by a developing roller as a developer carrying member, conveys the developer to a position facing the photoconductor 2, and supplies toner to the electrostatic latent image on the photoconductor 2. Develop this. The transfer device 12 includes a transfer roller as a transfer member, and transfers the toner image formed on the photoreceptor 2 to a transfer target such as a recording sheet. The cleaning device 4 includes a cleaning blade that comes into contact with the photoreceptor 2 and scrapes off transfer residual toner from the surface thereof. In addition, the image forming apparatus includes a sheet feeding unit (not shown) that feeds the recording paper to a facing portion between the photoconductor 2 and the transfer device 12, and a fixing unit (not shown) that fixes the image on the recording paper to which the toner image is transferred. Yes.

  In the printer of this embodiment, a lubricant application device 11 that applies a lubricant to the photoreceptor 2 is provided. The purpose of applying the lubricant to the photoconductor 2 is to reduce the coefficient of friction of the photoconductor 2 and to prevent the adhesion of charged products and to suppress the influence of the charging hazard, thereby improving the high image quality durability of the photoconductor 2. is there. Further, by reducing the coefficient of friction of the photoreceptor 2, the toner or toner additive is less likely to pass through the cleaning blade 4, and the cleaning performance of the photoreceptor 2 is improved. Recently, the toner has been reduced in particle size or spheroidized, so that it is possible to cope with these toners in which improvement in cleaning properties is important. In the image forming apparatus of FIG. 1, the lubricant application device 11 is disposed immediately upstream of the rotation direction of the photosensitive member 2 from the cleaning blade 4, and the lubricant is applied to the photosensitive member 2, whereby the friction coefficient with the cleaning blade 4 is obtained. Is effectively reduced. Further, it is preferable to use at least the outermost layer cured as the photoreceptor 2. Specifically, those using monofunctional donors + trifunctional or higher monomers proposed in Japanese Patent Application Laid-Open Nos. 2004-302452, 2004-302450, and 2004-302451 can be mentioned.

  In the image forming apparatus according to the present embodiment, as shown in FIG. 1, a photosensitive member 2, a charging device 3, a lubricant applying device 11, and a cleaning device 4 are integrally formed, and the process cartridge 1 can be attached to and detached from the main body. It has become. The process cartridge 1 can be pulled out from the image forming apparatus along a guide rail (not shown) fixed to the main body of the image forming apparatus. Further, the process cartridge 1 can be loaded at a predetermined position by pushing the process cartridge 1 into the main body of the image forming apparatus.

  Next, the lubricant application device 11 will be described. The lubricant application device 11 includes a brush roller 6 as a member applied to the photoreceptor 2, a solid lubricant 7 such as zinc stearate, and an urging unit that presses and urges the solid lubricant 7 toward the brush roller 6. A pressure spring 9 and a brush roller support member 8 that supports the brush roller 6 so as to be movable in the contact / separation direction with respect to the photoreceptor 2, and the brush roller 6 is pressed against the photoreceptor 2 via the brush roller support member 8. And a pressing spring 10 for biasing. The brush roller 7 scrapes and holds the solid lubricant 7 pressed by the pressure spring 9 while rotating, and rubs the surface of the photoreceptor 2 to apply it. Here, the solid lubricant 7 is held with respect to the brush roller support member 8 via a pressure spring 9, and can be moved in a direction in which the solid lubricant 7 is in contact with or separated from the brush roller 6. It is pressed and urged to come into contact. The brush roller 6 is held by a pressure spring 10 with respect to the frame of the process cartridge 1 and can move in a direction in which the brush roller 6 contacts and separates from the photoconductor 2. It is urged to touch. By doing so, even if the brush roller 6 falls over time and the apparent brush roller diameter becomes small, the pressure spring 10 is urged so as to be movable so as to contact the photoreceptor 2. Therefore, the contact between the brush roller 6 and the photosensitive member 2 can be maintained. The pressure spring 10 is adjusted so as to press and urge the brush roller 6 against the photoconductor 2 with a pressing force that rubs on the photoconductor 2 in a state where the amount of biting of the brush roller 6 is stable and good. Yes. Therefore, the lubricant application brush roller maintains the effect of rubbing the surface of the image carrier by rotation, and can apply the lubricant uniformly and stably over a long period of time.

Further, as shown in FIG. 2, a biting amount suppression member 12 that prevents the brush roller 6 from biting into the photoconductor 2 is provided between the photoconductor 2 and the brush roller support member 8. In this lubricant application device 11, the brush roller 6 is pressed and biased by the pressure spring 10 so as to come into contact with the photosensitive member 2. If the brush roller 6 bites too much into the photosensitive member 2, the brush roller 6 is promoted to fall down. As a result, uniform application of the lubricant may be difficult. Therefore, by providing the biting amount suppressing member 12 to regulate the biting amount, the contact state between the brush roller 6 and the photosensitive member 2 can be maintained with higher accuracy and the hair of the brush roller 6 by the pressing with the photosensitive member 2 can be maintained. Suppress the fall.

  Further, the biting amount suppression member 12 is a member that wears over time due to contact with the surface of the photoconductor 2, and the amount of biting of the brush roller 6 into the surface of the photoconductor 2 becomes variable by wearing over time. To. Thereby, while maintaining the contact state of the brush roller 6 and the photoconductor 2 with high accuracy over a long period of time, it is possible to suppress the falling of the brush roller 6 due to the pressing with the photoconductor 2. Specific examples of the biting amount suppressing member 12 include the same polyurethane rubber as that used for the cleaning blade 4 and a rubber hardness of 60 to 80 (JIS-A). Moreover, the thing of circular shape as shown in FIG. 2 and the thing similar to the cleaning blade 4 are mentioned. The results of experiments using a cleaning blade shape are shown below. The cleaning blade-shaped biting amount suppressing member 12 is disposed so as to be pressed against the photosensitive member 2 with a pressing force about ten times that of a normal cleaning blade 4. In the image forming apparatus of the present embodiment, the amount of falling of the brush roller 6 was 100K and the outer diameter was 0.2 mm. Further, the wear amount of the tip of the normal cleaning blade 4 is a scraping amount of about 0.02 mm when printing 100K sheets with a pressure of 0.2 N / cm. Therefore, if the pressing force of the cleaning blade shape biting amount suppressing member 12 is about 10 times (2.0 N / cm) that of the normal cleaning blade 4, the biting amount suppressing member 12 is about 0.2 mm when printing 100K sheets. It is possible to maintain the contact state between the brush roller 6 and the photoreceptor 2 with respect to the amount of hair fall over time. Further, it is possible to suppress the falling of the hair of the brush roller 6 due to the pressing with the photoreceptor 2.

  FIG. 3 shows a schematic configuration diagram of a modified example of the lubricant application device 11. In the lubricant application device 11 of FIG. 3, the brush roller 6 moves in a direction in which the rotation center axis moves toward and away from the photoreceptor 2 by moving around a predetermined rotation axis via the brush support member 8. It is a configuration. At this time, the rotation axis of the brush roller 6 (hereinafter referred to as a support point) and the pressure point of the pressure spring 10 are different. In such a lubricant application device 11, the direction of the force when the pressure spring 10 is pressed and urged so as to rotate the rotation center axis of the brush roller 6 in a direction in contact with the photosensitive member 2 is the brush roller 6. The rotation center axis of the photosensitive member 2 and the rotation center axis of the photosensitive member 2 are configured to be substantially parallel to the direction connecting the rotation center axis. FIG. 4 shows the relationship between the support point (point A in the figure) of the brush roller 6 and the pressure point (point B in the figure) of the pressure spring 10. In order for the direction of the force to be substantially parallel to the direction connecting the rotation center axis of the brush roller 6 and the rotation center axis of the photoreceptor 2, the force direction passes through the rotation center axis of the brush roller 6, The intersection of the perpendicular to the line connecting the centers of the photoconductors 2 and the support shaft for spring pressing needs to be point A. By doing so, the force vector applied to the brush roller 6 at the nip portion between the brush roller 6 and the photosensitive member 2 is substantially at the center of the photosensitive member 2, so that the amount of biting of the brush roller 6 is stabilized. Can be made. In particular, the brush roller 6 may rotate with the photosensitive member 2 at a linear speed ratio. In such a case, when the pressure is applied by two springs 9, the posture of the brush roller 6 is stabilized, and the brush roller 6 This is effective for stabilizing the rotation of the.

  Further, in the lubricant application device 11 of FIG. 3, the cleaning blade 4 that is in contact with the surface of the photoreceptor 2 may be provided with a function as a biting suppression member without providing the biting amount suppression member 12 separately. In FIG. 3, the cleaning blade 4 is supported by a part of the brush support member 8, and the cleaning blade 4 has a function of maintaining the distance between the brush roller 6 and the photoreceptor 2. The cleaning blade 4 is made of urethane resin or the like, and is gradually worn by cleaning the toner and the toner additive over time, so that the amount of biting between the brush roller 6 and the photosensitive member 2 is accurately maintained over a long period of time. . Accordingly, it is possible to maintain the contact state between the brush roller 6 and the photosensitive member 2 and to prevent the brush roller 6 from falling down due to the pressing with the photosensitive member 2. Thus, by providing the cleaning blade 4 with a function as a biting suppression member, it is not necessary to provide a biting suppression member separately, and the process cartridge 1 can be downsized.

  FIG. 5 is a schematic view of a state in which a lubricant is applied on the photoreceptor 2. FIG. 5A is a schematic diagram showing a state in which the brush roller 6 has fallen down and the contact state with the photoreceptor 2 becomes unstable in a conventional lubricant application device. The coating amount on the photoreceptor 2 is not uniform. FIG. 5B is a schematic diagram of the apparatus using the lubricant application device of this embodiment. Even if the brush roller 6 falls down, the brush roller 6 bites into the photoconductor 2 and maintains the effect of the brush roller 6 rubbing the photoconductor 2, so that the coating amount on the photoconductor 2 becomes uniform. ing. Furthermore, since the coating amount becomes uniform, the coating amount can be reduced as shown in FIG. In order to reduce the amount of application, the pressure applied to the brush roller 6 by the fixed lubricant 9 may be reduced. By reducing the pressure applied to the brush roller 6 by the fixed lubricant 9, it is possible to suppress the falling of the hair over time, and a stable and uniform application can be performed.

Table 1 shows the result of experimentally confirming the relationship between the amount of lubricant applied to the photosensitive member 2 and the uniformity when the amount of brush biting is reduced due to the falling of hair. The experimental condition is the result of removing the cleaning blade 4 that is in contact with the photosensitive member 2 and rotating the photosensitive member 2 (no change otherwise). The outer diameter of the brush roller 6 of the machine tested was 12 mm (bite-in amount 1.5 mm). When the outer diameter is about 10 mm (bite-in amount of 0.5 mm), lubricant-coated brush eyes (unevenness of brush pitch application) on the photoreceptor are observed. This is a result that the outer diameter of the brush roller 6 is reduced and the brush is not rubbed on the photosensitive member 2 so that the lubricant is applied in a brush shape. As described above, it is important to reduce the fluctuation of the amount of biting between the brush roller and the photosensitive member 2 over time.

  Next, driving of the brush roller 6 will be described. As described above, the brush roller 6 is movable with respect to the contact / separation direction with respect to the photoreceptor 2, and the position in the process cartridge 11 is indefinite. Therefore, it is desirable that the brush roller 6 is driven separately from the photosensitive member 2 as shown in FIG. Further, a mode is provided in which the brush roller 6 is controlled to rotate in a direction opposite to that during image formation (hereinafter referred to as reverse rotation) for a predetermined time during non-image formation. FIG. 7 is an example of a timing chart for rotating the brush roller 6 in the reverse direction. At the end of image formation, the brush roller 6 performs reverse rotation. At the end of the image formation, the time for turning off the photoconductor motor 13 (not shown) is lengthened and extended to the time for the brush roller 6 to reversely rotate. Although the reverse rotation time is appropriately determined, in this embodiment, it is set to about 1 sec to 3 sec. Thereby, the fall of the hair of the brush roller 6 can be suppressed, and more stable application of the lubricant can be achieved.

  In the image forming apparatus of the above embodiment, only the photosensitive member has been described as the image carrier. However, the lubricant application device 11 is not limited to the photoconductor 2 but can be applied to, for example, an intermediate transfer belt as an image carrier, and similar effects can be obtained.

As described above, according to the present embodiment, the lubricant application brush roller maintains the effect of rubbing the surface of the image carrier equivalent to that in the initial stage and applies the lubricant uniformly and stably over a long period of time. Can do.
Further, by providing the biting amount suppressing member 12 that wears with time due to contact with the surface of the photosensitive member 2, the amount of biting between the brush roller 6 and the photosensitive member 2 can be stabilized accurately over a long period of time, and Hair fall of the brush roller 6 due to pressing can be suppressed.
Further, the photosensitive member 2 formed by curing the outermost layer, the non-contact charging device 2 and the lubricant applying device 11 are formed into a process cartridge so that the photosensitive member can be effectively exposed. Simultaneously with improving the mechanical durability (abrasion resistance) of the body, it is possible to suppress the occurrence of image blur and the like and to improve the high-quality durability of the photoreceptor.
Further, the brush roller 6 is configured to move in a direction in which the rotation center axis moves around a predetermined rotation axis via the brush support member 8 so as to come in contact with and away from the photoreceptor 2. The direction of the force when pressing and urging the rotation center axis of the brush roller 6 in a direction in contact with the photosensitive member 2 connects the rotation center axis of the brush roller 6 and the rotation center axis of the photosensitive member 2. It is configured to be substantially parallel to the direction. By doing so, the force vector applied to the brush roller 6 at the nip portion between the brush roller 6 and the photosensitive member 2 is substantially at the center of the photosensitive member 2, so that the amount of biting of the brush roller 6 is stabilized. Can be made.
In addition, since the cleaning blade 4 with which the photosensitive member 2 abuts has a function of suppressing the amount of biting, it is not necessary to provide a biting suppression member separately, and the apparatus can be miniaturized. In the image forming apparatus, it is possible to realize an image forming apparatus that achieves various requirements such as high image quality and miniaturization, long life of the photoreceptor, and energy saving.
In the image forming apparatus provided with the process cartridge 1, the maintainability is improved.
In addition, by providing a mode in which the brush roller 6 is rotated in the opposite direction to that during image formation during non-image formation, it is possible to prevent the brush from falling down and to apply a more stable lubricant.

1 is a schematic configuration diagram of a main part of an image forming apparatus according to an embodiment of the present invention. 1 is a schematic configuration diagram of a lubricant application device provided with a biting amount suppressing member. The schematic block diagram of the lubrication agent coating device which concerns on a modification. Explanatory drawing of the direction of the force by the pressurization means of the lubricant coating device which concerns on a modification. (A) Explanatory drawing of the application | coating state on the photoreceptor in the conventional lubricant coating device. (B) Explanatory drawing of the application | coating state on the photoreceptor in the lubricant application means of this embodiment. (C) Explanatory drawing of the state which reduced the application quantity in the lubricant application means of this embodiment. Explanatory drawing of the drive method of a brush roller. Timing chart for reversing the brush roller.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Process cartridge 2 Photoconductor 3 Charging device 4 Cleaning blade 5 Developing device 6 Brush roller 7 Solid lubricant 8 Brush roller support member 9 Pressure spring 10 Pressure spring 11 Lubricating application device 12 Biting amount suppression member 13 Motor 14 Transfer roller

Claims (8)

A lubricant, a lubricant application brush roller that applies the lubricant to the surface of the image carrier while being rotationally driven, and a lubricant pressurizing unit that presses and urges the lubricant against the lubricant application brush roller. In a lubricant application device that scrapes the lubricant with the lubricant application brush roller and applies it to the surface of the image carrier.
The lubricant application brush roller is movable in a direction in which the lubricant application brush roller is in contact with or separated from the image carrier, and brush roller pressurizing means for pressing and urging the lubricant application brush roller against the image carrier is provided. Lubricant application device.   2. The lubricant application device according to claim 1, further comprising a biting amount suppression member that regulates an amount of biting of the lubricant application brush roller into the surface of the image carrier between the surface of the image carrier and the bite amount suppression member. The lubricant application is characterized in that the amount of biting of the lubricant application brush roller into the surface of the image carrier can be changed over time by being worn over time by contact with the surface of the image carrier. apparatus. At least an electrostatic latent image carrier formed by curing the outermost layer, a non-contact type charging means arranged close to the surface of the electrostatic latent image carrier, and a lubricant on the surface of the electrostatic latent image carrier In a process cartridge that integrally forms an agent and a lubricant application means for application, and is detachable from the image forming apparatus main body,
A process cartridge comprising the lubricant application device according to claim 1 or 2 as the lubricant application means.   4. The process cartridge according to claim 3, wherein the lubricant application brush roller is configured to move in a direction in which the rotation center axis moves around a predetermined rotation axis so as to come in contact with and separate from the image carrier. The direction of the force when the brush roller pressing means presses and urges the rotation center axis of the lubricant application brush roller to rotate in a direction in contact with the image carrier is the rotation center of the lubricant application brush roller. A process cartridge, wherein the process cartridge is configured to be substantially parallel to a direction connecting a shaft and a rotation center axis of the electrostatic latent image carrier. At least an electrostatic latent image carrier formed by curing the outermost layer, a non-contact type charging means arranged close to the surface of the electrostatic latent image carrier, and a lubricant on the surface of the electrostatic latent image carrier A process cartridge that is integrally formed with a lubricant applying means for applying the agent and a cleaning blade that contacts the surface of the latent electrostatic image bearing member and removes residual toner on the surface, and is removable from the main body of the image forming apparatus In
The cleaning blade functions as a biting amount suppression member that regulates the biting amount of the lubricant-applying brush roller to the surface of the image carrier, and the cleaning blade is worn over time due to contact with the surface of the image carrier. Thus, the process cartridge is configured such that the amount of biting of the lubricant application brush roller into the surface of the image carrier can be changed over time. In an image forming apparatus comprising an image carrier and a lubricant application device for applying a lubricant on the image carrier,
An image forming apparatus, wherein the lubricant applying apparatus according to claim 1 or 2 is adopted as the lubricant applying apparatus. Electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the surface of the electrostatic latent image carrier, and developing means for developing the electrostatic latent image on the electrostatic latent image carrier In the image forming apparatus as a process cartridge that integrally forms a plurality of these and is detachable from the main body,
An image forming apparatus comprising the process cartridge according to claim 3, 4 or 5 as the process cartridge.   8. The image forming apparatus according to claim 6, wherein a mode for controlling the lubricant application brush to rotate in a direction opposite to a direction in which the lubricant application brush roller is rotated during image formation is provided during non-image formation. An image forming apparatus.

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