JP4621434B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus, and more particularly to a lubricant supply means for supplying a lubricant onto a surface of an image carrier before being charged by a charging device after a toner image is transferred to a transfer material. It is.

  Conventionally, as an electrophotographic process, an electrostatic charge image (electrostatic latent image) is formed on a photoconductor using a photoconductive phenomenon, and charged fine particles (toner) colored on the electrostatic latent image are electrostatically discharged. A process is known in which a power image is applied to form a visible image. In this electrophotographic process, a lubricant is applied to the surface of a toner image carrier such as a photoreceptor or an intermediate transfer belt in order to improve image quality and cleaning properties. Examples of the lubricant include various waxes, fluorine-based resins (such as polytetrafluoroethylene and polyvinylidene fluoride), and higher fatty acid metal salts (such as zinc stearate). By applying the lubricant to the surface of the toner image carrier, the friction coefficient of the surface is reduced. When the friction coefficient on the surface of the toner image carrier is reduced, the deposits attached to the surface can be easily removed from the surface. It is also known that when the above-described toner image carrier is a photoreceptor, applying a lubricant is useful for preventing wear of the photoreceptor due to cleaning. That is, the photoconductor is usually cleaned by mechanically rubbing the surface of the photoconductor with a cleaning blade or a cleaning brush. Although the photoconductor wears due to this rubbing, reducing the friction coefficient of the photoconductor surface by applying a lubricant is also effective in preventing such wear.

  By the way, these lubricants are supplied to the surface of the photoreceptor in the form of powder in small amounts. As a specific method, as disclosed in Patent Document 1, there is known a method in which a lubricant solidly formed into a block shape is scraped off and applied by an application means such as a brush.

JP 2000-162881 A

However, it is difficult to apply the lubricant uniformly on the surface of the photoreceptor without unevenness by the method of simply applying it through the brush. Many solid lubricants contain a powder having a particle size of about several μm in the molding process. When the lubricant is applied to the photoreceptor by the method described in Patent Document 1, if a shearing force is applied to the powder when the brush rubs the solid lubricant, the powder is cracked, and submicron to nanometer ^-It becomes a particle size of order (10 ^<-7 > ^-10 <^-9> m order). The lubricant having a shearing force is supplied to the photoconductor with a small particle size. On the other hand, there is also a powder that directly adheres to the brush with a particle size of micron order (10 ⁻⁶ m order) without applying a shearing force, and is directly applied to the surface of the photoreceptor. Powders with a small particle size, that is, submicron to nanometer order powders can be easily and uniformly applied, but the surface on which such a particle size powder is applied is further micron order. It is difficult to uniformly apply the powder. In addition, it has been found that the powder having a particle size of the order of microns cannot exhibit sufficient lubricity even if applied to the surface of the photoreceptor, and deteriorates the cleaning performance by the cleaning member. ing.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an image forming apparatus for applying a lubricant on an image carrier, in which the lubricant applied on the image carrier is lubricated. The present invention is to provide an image forming apparatus that exhibits the performance more effectively than before and can suppress the deterioration of the cleaning performance by the cleaning member.

In order to achieve the above object, the invention of claim 1 includes an image carrier that carries an electrostatic latent image, a charging device that charges the surface of the image carrier, and a developer carried on the developer carrier. A developing device that transports the toner image to a developing region facing the image carrier and develops a latent image on the image carrier to form a toner image; and transfers the developed toner image onto a transfer material and then onto the image carrier. A cleaning means for removing residual transfer residual toner, and a lubricant containing portion that contains a lubricant on the surface of the image carrier after the toner image is transferred to a transfer material and before being charged by a charging device. in the image forming apparatus having a lubricant supply means for supplying the agent, a plurality of lubricant supply brush you feed carrying-transportable with lubricant by said lubricant supply means is rotated, a plurality of lubricant At least one of the supply brushes from the lubricant container Is supplied to the lubricant, it supplies the image bearing member onto the surface after passing through a lubricant accommodating unit from said lubricant supply lubricant supplied to the brush plurality of lubricant supply brush between rubbing portions It is characterized by.
According to a second aspect of the present invention, in the image forming apparatus of the first aspect, the lubricant supplied from the lubricant accommodating portion to the lubricant supply brush is passed through the two or more lubricant supply brushes. And supplied onto the surface of the image carrier .
According to a third aspect of the present invention, in the image forming apparatus of the first aspect, the plurality of lubricant supply brushes abut on the surface of the image carrier, and the lubricant supplied from the lubricant accommodating portion is supplied to the image forming apparatus. It is characterized by being applied to the surface of the carrier .
The invention of claim 4 is the image forming apparatus according to any one of claims 1 to 3, and characterized in that a movable toward and away from said lubricant accommodating unit with respect to the lubricant supply brush To do.
According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, a lubricant heating member for heating the lubricant carried by the lubricant supply brush is provided. It is a feature.
According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects, a solid lubricant is disposed in the lubricant accommodating portion, and the plurality of lubricant supply brushes are arranged. At least one of the lubricants is in contact with the solid lubricant and rotates to scrape off a part of the solid lubricant, whereby the lubricant is supplied from the lubricant container to the lubricant supply brush. Is.
The invention of claim 7, wherein the image forming apparatus according to any one of claims 1 to 5, fine powder-like lubricant particle size specification system means for supplying only to the lubricant supplying brush lubricant the is characterized in that provided in the lubricant accommodating unit.
According to an eighth aspect of the present invention, in the image forming apparatus according to any one of the first to seventh aspects, a lubricant pulverizing means for converting the lubricant into a fine powder is used as the image of the lubricant supply brush . It is arranged to oppose the surface of the image carrier on the downstream side in the moving direction of the carrier surface.
According to a ninth aspect of the present invention, in the image forming apparatus according to any one of the first to eighth aspects, the charging device uses a charging roller that is in contact with or close to the image carrier. It is characterized by being.
The invention of claim 10 is the image forming apparatus according to any one of claims 1 to 9, the volume resistivity of the upper Symbol lubricant ^{1.0 × 10 9 ~1.0 × 10 15} Ω -It is characterized by being cm.
The invention according to claim 11 is the image forming apparatus according to any one of claims 1 to 10, wherein the toner forming the toner image has a circularity of 0.96 or more. It is.
According to a twelfth aspect of the present invention, in the image forming apparatus according to any one of the first to eleventh aspects, the lubricant supply unit is supported together with at least the image carrier, and is detachable from the main body of the image forming apparatus. It is characterized by having a certain process cartridge.

In the image forming apparatus according to any one of claims 1 to 12 , the lubricant supplied to the lubricant supply brush from the lubricant container passes through a portion where the plurality of lubricant supply brushes rub against each other, so that the lubricant has a shearing force. As a result, the particle size of the powder is reduced, and the lubricant is made into a fine powder smaller than a predetermined particle size. Therefore, the lubricant can be uniformly applied on the image carrier.
Further, in the above-described image forming apparatus having a configuration according to claim 7, in Jun lubricant particle size specification system means supplies only a small fine powder-like lubricant than the predetermined particle size to the lubricant supply means. Therefore, the lubricant can be uniformly applied on the image carrier.
Further, in the image forming apparatus having the configuration of the above-described eighth aspect, the lubricant on the image carrier is supplied by the lubricant pulverizing means at a position opposed to the image carrier surface downstream in the moving direction of the image carrier surface. A fine powder smaller than a predetermined particle size is formed. Therefore, the lubricant can be uniformly applied on the image carrier.

According to the first to twelfth aspects of the present invention, since the lubricant can be uniformly applied onto the image carrier, the lubricant exhibits lubricity, and the image carrier cleaning means exhibits its cleaning performance. There is an excellent effect of being able to.

[Implementation-shaped state]
Hereinafter, the present invention is an image forming apparatus powdery developing electrophotographic copying machine (hereinafter "referred copier") an embodiment is applied to a (hereinafter, referred performed shaped on purpose) will be described.
Figure 1 shows, as an example of an image forming unit of the copying machine according to an exemplary shape state is a schematic diagram of an image forming unit 1 of a tandem type full-color copier. In the figure, reference numeral 6 denotes a transfer material, which is an endless belt-like intermediate transfer belt stretched around a drive roller 6a and a transfer roller 6b. Consisting of the intermediate transfer belt 6, the photosensitive member 2 is formed of four image carriers that form four color toner images of yellow (Y), magenta (M), cyan (C), and black (BK). An image forming unit 10 is provided. Here, FIG. 2 is a schematic configuration diagram of one of the image forming units 10.
The photoreceptor 2 of the image forming unit 10 forms an electrostatic latent image on the surface, and the following is disposed around the photoreceptor 2. A charging roller 3 that is a charging device that uniformly charges the surface of the photoreceptor 2, an exposure device 4 that irradiates the surface of the photoreceptor 2 with image light to form a latent image, and a latent image formed on the photoreceptor 2. A developing device 5 is provided that selectively transfers toner to form a toner image. Further, a solid lubricant 100 as a lubricant container, lubricant application brushes 150 and 151 as lubricant supply brushes for supplying a lubricant onto the surface of the photoreceptor 2, a cleaning unit 13 as a cleaning means, and the like are arranged. ing. Further, a primary transfer roller 9 is provided so as to face the photoconductor 2 and transfer the toner image on the photoconductor 2 onto the intermediate transfer belt 6 . By using the Jun lubricant application brush, the lubricant always can be supplied stably with a simple apparatus configuration. A voltage necessary for transferring the toner image is applied to the primary transfer roller 9 by a bias circuit (not shown). A transfer roller 6 b and a secondary transfer roller 7, which are a pair of secondary transfer rollers, are provided on the downstream side in the conveyance direction of the intermediate transfer belt 6 from the image forming unit 10.

Next, an image forming operation will be described. The photosensitive member 2 is rotated in the clockwise direction in FIG. 1 to uniformly charge the photosensitive member 2 with the charging roller 3, and then the exposure device 4 irradiates a laser modulated with image data to statically apply the photosensitive member 2 to the photosensitive member 2. An electrostatic latent image is formed. The developing device 5 attaches toner to the photosensitive member 2 on which the electrostatic latent image is formed, and develops it. The toner image formed on the photoreceptor 2 by the developing device 5 is transferred to the intermediate transfer belt 6 by the primary transfer roller 9. Such image formation is performed by the image forming units 10Y, 10M, 10C, and 10BK, and a full-color image is formed on the intermediate transfer belt 6. The full-color image formed on the intermediate transfer belt 6 is transferred to the recording paper P conveyed between the transfer roller 6a as the secondary transfer portion and the secondary transfer roller 7. The recording material P to which the full-color image has been transferred is conveyed to a fixing unit (not shown).
The fixing unit includes a fixing roller that is heated to a predetermined fixing temperature by a built-in heater, and a pressure roller that is pressed against the fixing roller with a predetermined pressure. The recording paper P conveyed from the secondary transfer unit is heated and pressurized to fix the toner image on the recording paper on the recording paper, and then discharged onto a paper discharge tray (not shown).
On the other hand, the photosensitive member 2 having transferred the toner image to the intermediate transfer belt 6 at the portion facing the primary transfer roller 9 is further rotated, and the toner remaining on the surface of the photosensitive member 2 is scraped off by the cleaning blade 13b of the cleaning portion 13. And removed. Static elimination is performed by the photoreceptor neutralization device 8. After the photoreceptor 2 that has been neutralized by the photoreceptor neutralization device 8 of the image forming unit 10 is uniformly charged by the charging device 3, the next image formation is performed in the same manner as described above. The cleaning unit 13 is not limited to the one that scrapes the residual toner on the photoconductor 2 with the cleaning blade 13b, and may be one that scrapes the residual toner on the photoconductor 2 with a fur brush, for example.
The charging roller 3 is a hard conductive roller disposed with a small gap with respect to the photoreceptor. Here, the proximity type conductive roller is used as the charging device, but the charging device is not limited to this, and other charging methods such as contact roller charging and scorotron charging may be used.

Was then applied in an exemplary form state is described charging roller 3. FIG. 3 is a schematic view of the charging roller 3 which is a proximity charging device.
The charging roller 3 includes a conductive substrate 201 and a surrounding resistance layer. The conductive substrate 201 is a stainless steel cylindrical member having a diameter of 8 to 20 mm. The conductive substrate 201 may be reduced in weight by using aluminum, which is a highly conductive metal, or a conductive resin having a volume resistivity of the order of 10 ² Ω · cm or less.
The resistance layer 202 is made of a polymer material obtained by kneading a conductive material into ABS resin or the like, and a fluorine-based resin is formed as a thin layer 203 on the surface thereof. Examples of conductive materials include metal ion complexes, carbon black, and ionic molecules. In addition, a material capable of performing uniform charging may be used.
The surface of the charging roller 3 moves in the same direction as the surface of the photoreceptor 2. Here, the charging roller 3 may be in a stationary state without rotating together with the photoreceptor 2. The length of the charging roller 3 in the longitudinal direction (axial direction) is set slightly longer than the maximum image width A4 side (about 290 mm). The charging roller 3 is provided with spacers at both ends in the longitudinal direction, and the surface to be charged on the surface of the photosensitive drum 2 and the surface of the charging roller 3 are brought into contact with the non-image forming regions at both ends of the photoreceptor 2. The gap H between the first and second charged surfaces is held so that the distance at the closest portion is 5 to 100 μm. This closest distance is more preferably set to 30 to 65 μm. In this embodiment, the thickness is set to 55 μm.
A charging power source is connected to the charging roller 3. As a result, the surface to be charged is uniformly charged by discharge in the gap H between the surface to be charged on the surface of the photoreceptor 2 and the surface to be charged on the surface of the charging roller 3. The applied voltage bias is preferably a voltage waveform in which an AC voltage is superimposed on a DC voltage, and the peak-to-peak voltage of the AC voltage is preferably at least twice the charging start voltage. Further, if necessary, a DC voltage, preferably a constant current voltage may be used.

Figure 4 is a diagram showing an example of how to maintain a minute gap between the photoconductor 2 and the charging roller 3. FIG shaped state. The spacer member was formed as a spacer 302 by winding a film around both ends of the charging roller. The spacer 302 is brought into contact with the photosensitive surface of the photoreceptor 2 so as to obtain a certain minute gap H in the image area of the charging roller 3 and the photoreceptor 2. As the applied bias, an AC superposition type voltage is applied, and the photosensitive member 2 is charged by a discharge generated in a minute gap H between the charging roller 3 and the photosensitive member 2. Furthermore, the precision of maintaining the minute gap is improved by pressurizing the conductive base material 201 serving as the shaft with the spring 303 or the like.
Further, the spacer as the gap member may be integrally formed with the charging roller. At this time, at least the surface of the spacer portion is preferably an insulator. By doing so, the discharge is eliminated in the gap portion, the discharge product is deposited on the spacer portion, and the toner adheres to the gap portion due to the adhesiveness of the discharge product, so that the gap is not widened.

The gap member may be a heat-shrinkable tube, and this method is most preferable at the present time. Examples of the heat shrinkable tube include a Sumitube (trade name: F 105 ° C, manufactured by Sumitomo Chemical Co., Ltd.) for 105 ° C. Although the thickness of the Sumitube is 300 μm, depending on the diameter of the charging member to be mounted, the heat shrinkable tube shows a shrinkage rate of about 50-60%, and the thickness increases by about 0-200 μm due to heat shrinkage. Cutting processing that takes into account the minute is necessary. For example, when a spacer member is mounted on a φ12 mm charging member, a heat shrinkable tube having a cutting depth of 350 μm and an inner diameter of about 15 mm may be used. After mounting the heat shrinkable tube on the cutting part at the end of the charging member, the charging member is rotated and inwardly heated from the end surface while being heated with a heat source at 120 to 130 ° C., thereby uniformly shrinking the charging member and the image. The gap between the supports can be set to about 50 μm. The heat-shrinkable and fixed heat-shrinkable tube does not come off during use, but for prevention, a liquid adhesive such as cyanoacrylate resin (for example, Aron Alpha (trademark), Cyanobond (trademark)) at the end. Can be poured and fixed.
Since the heat-shrinkable tube has a thickness, when the spacer member is used, there is a method of taking a step 601 and attaching the spacer member as shown in FIG. Another method is shown in FIGS. In FIG. 6, a groove 602 is formed leaving a part of the end of the resistance layer, and a square ring spacer member having endless stretchability is mounted in the groove. In FIG. 7, the resistance layer 202 is cut to have a round shape to form a groove 603, and a circular ring-shaped (usually referred to as O-ring) spacer member is mounted. It is desirable to sharpen the edges to make it easier to insert the spacer member, or it can be completely cut and fixed with an adhesive. In the case where the spacer member is mounted and fixed on the portion where the cut portion or groove is formed, it is desirable to use an adhesive such as a two-component epoxy resin in addition to the liquid adhesive described above.
Further, the spacer member may be a roller member by inserting a member having a diameter larger than that of the charging roller later.

Next will be an explanation construction features of the exemplary shaped state. In this configuration, a lubricant rubbing member serving as a lubricant pulverizing unit is provided on a lubricant applying member serving as a lubricant supplying unit. Figure 8 is a schematic view of a lubricant supply unit of the embodiment shaped condition shown in Figure 2. The solid lubricant 100 is applied to the photoconductor 2 through two lubricant application brushes 150 and 151 rotating in the same direction. The first lubricant application brush 150 rotates in contact with the solid lubricant 100 and scrapes a part of the solid lubricant 100. The solid lubricant 100 scraped off adheres to the first lubricant application brush 150, rotates, moves when it contacts another rotating second lubricant application brush 151, and further rotates, It is applied to the body 2. At this time, when moving from the first lubricant application brush 150 to the second lubricant application brush 151, the solid lubricant 100 is subjected to a shearing force by rubbing between the lubricant application brushes, and the particle size of the powder is reduced. It becomes small and becomes a fine powder smaller than a predetermined particle size. Further, while moving the two lubricant application brushes 150 and 151, a part of the solid lubricant 100 is removed from the two lubricant application brushes 150 and 151 by centrifugal force. Since the powder having a larger particle size has a larger centrifugal force, the solid lubricant applied to the photoreceptor 2 has a smaller particle size. That is, the two lubricant application brushes 150 and 151 that are lubricant application members also serve as a lubricant rubbing member that is a lubricant pulverization means. It is desirable that the particle size of the pulverized lubricant rubbed with the two lubricant application brushes 150 and 151 is 1.0 μm or less.
2 and 8 show a configuration including two lubricant application brushes, but not limited to two, a plurality of lubricant application brushes are provided, and the lubricant is slid when transferred from the lubricant application brush to the lubricant application brush. Any configuration that is rubbed is acceptable. In FIG. 8, the first lubricant application brush 151 and the second lubricant application brush 151 rotate in the same direction, but the rotation directions of the two lubricant application brushes may be reversed.

  At this time, the second lubricant application brush 151 in contact with the image carrier can also serve as a cleaning lubricant application brush. That is, the upstream side of the second lubricant application brush 151 in the rotational direction of the second lubricant application brush 151 in contact with the photosensitive member 2 carries the lubricant, and the residual toner on the surface of the photosensitive member 2 from the portion in contact with the photosensitive member downstream of the rotational direction. Scratch up. The residual toner thus scraped is collected from the second lubricant application brush 151 by a collecting member (not shown). If the cleaning by the second lubricant application brush 151 at this time is insufficient, as shown in FIG. 2, a cleaning blade 13b is provided downstream of the second lubricant application brush 151 in the rotation direction of the photosensitive member 2. Also good. By performing the cleaning with the lubricant application brush before the cleaning with the blade, the residual toner on the photoreceptor 2 rubbed with the lubricant application brush is easily cleaned by the cleaning blade 13b.

Further, the positional relationship between the lubricant application brush as the lubricant application member and the cleaning blade 13b as the cleaning member is not limited to the configuration of FIG. For example, the lubricant applying member may be installed downstream of the cleaning blade 13b in the photosensitive member rotation direction, and a fur brush as a cleaning unit may be provided upstream of the cleaning blade in the photosensitive member rotation direction. Thus, the cleaning performance can be improved by providing the fur brush as the cleaning means separately from the lubricant application brush as the lubricant application member. Further, since the lubricant is applied to the surface of the photoreceptor after being cleaned by the fur brush and the blade, the lubricity can be improved.
On the other hand, as shown in FIG. 2, if one lubricant application brush has a role as a lubricant application member and a role as a cleaning member, the number of members such as a drive mechanism for rotating the brush and the brush can be reduced. I can plan.

By the way, when a toner having a low sphericity is used, the transfer rate may deteriorate (the transfer rate of 85% at the worst value). In this case, a portion covered with untransferred toner exists on the image carrier. If there is a large amount of toner on the image carrier, background smearing will occur and uneven application of lubricant will occur on the image carrier. Then, the state of the surface of the image carrier changes, and cleaning may not be possible with normal blade cleaning.
Therefore, a fur brush as a cleaning member is made of conductive fibers, and a cleaning unit is provided for recovering residual toner from the image carrier by applying a voltage to the fur brush or a recovery member for recovering toner from the fur brush. May be.
By applying a voltage to the fur brush as a cleaning member, the fur brush attracts residual toner. Even when the surface state changes due to NOx or the like adhering to the surface of the photoconductor or the coefficient of static friction changes, the cleaning member deforms and contacts with the surface state, thus maintaining good cleaning properties. be able to. Further, by controlling the magnitude of the applied voltage, the toner on the photoreceptor can be cleaned well without causing a reduction in the cleaning margin due to fluctuations in the amount of input toner. Furthermore, even a residual toner having a circularity of 0.96 or more, which is difficult to collect with a conventional cleaning member, can be easily cleaned.
Thereby, even if there is uneven application of the lubricant, the cleaning performance is not deteriorated.

The lubricant application brush 151 in contact with the photosensitive member 2 can be brought into contact with and separated from the photosensitive member 2 at a predetermined timing by a mechanism using a solenoid (not shown), or the rotational speed thereof is changed to change the photosensitive member. The lubricant application amount on the body 2 can be controlled.
By the way, when the lubricant application brush 151 also serves as a cleaning fur brush, if the lubricant application brush 151 can be brought into and out of contact with the photosensitive member 2, there is a risk that a cleaning problem may occur. Therefore, in this case, a mechanism using a solenoid may be provided in the solid lubricant 100 that is the lubricant container, so that the solid lubricant 100 that is the lubricant application member can be brought into contact with and separated from the lubricant application brush 150 that is the lubricant application member at a predetermined timing. The predetermined timing at which the solid lubricant 100 is brought into contact with and separated from the lubricant application brush 150 is controlled in an arbitrary application state from the continuous operation to the intermittent operation. Thus, by controlling the contact / separation timing between the lubricant application brush 150 and the solid lubricant, the amount of lubricant applied to the photoreceptor 2 can be controlled.

  As the solid lubricant 100, for example, various waxes, fluorine resins (polytetrafluoroethylene, polyvinylidene fluoride, etc.), higher fatty acid metal salts (zinc stearate, etc.) and the like can be used. It is particularly preferable to use a lamellar crystal powder such as zinc stearate. A lamellar crystal has a layered structure in which amphiphilic molecules are self-organized, and when a shearing force is applied, the crystal breaks along the layers and becomes slippery. This action leads to a lower coefficient of friction, and the characteristics of the lamellar crystal that uniformly covers the surface of the photosensitive member by receiving a shearing force can effectively cover the surface of the photosensitive member with a small amount of lubricant. By reducing the friction coefficient, the blade of the cleaning unit 13 as a cleaning means can exhibit its cleaning performance.

Further, it has been found that by applying the solid lubricant in this manner, in addition to the effect as a lubricant, there is an effect as a protective substance that alleviates deterioration of the photoreceptor due to charging. In particular, it is useful in a charging device using the charging roller 3. This is especially true when using a system in which discharge occurs in the space between the photoconductor and the charging member that is placed close to or in contact with the photoconductor to charge the photoconductor, since the surface of the photoconductor tends to deteriorate. The effect as a substance is very large. For example, when a voltage in which an AC component is superimposed on a DC component is applied by a proximity charging method and a fatty acid metal salt is used as a lubricant, a metal element contained in the fatty acid metal salt present on the surface of the charged body in the discharge region The element ratio [%] is measured by XPS,
1.52 × 10 ⁻⁴ × {Vpp−2 × Vth} × f / v [%]
As described above, when a lubricant is applied to the photoreceptor, it has been found that the lubricant sufficiently functions as a protective substance.
(Where Vpp is the amplitude [V] of the AC component applied to the charging member,
f is the frequency [Hz] of the AC component applied to the charging member,
Gp is the closest distance [μm] between the surface of the charging member and the surface of the member to be charged.
v is the moving speed [mm / sec] of the surface of the charged object facing the charging member,
Vth is a discharge start voltage.
The value of Vth is the thickness of the object to be charged d [μm],
The dielectric constant of the object to be charged is εopc,
When the relative dielectric constant in the space between the charged body and the charging member is εair,
312 + 6.2 × (d / εopc + Gp / εair) + √ (7737.6 × d / ε)

Further, the lubricant used in the practice type condition, the volume resistivity is used within the scope of ^{1.0 × 10 9 ~10 15 Ω ·} cm. If the resistance of the lubricant is too low, thus reducing the surface resistance of the photosensitive member 2 when applied. As a result, the photosensitive member 2 cannot maintain the electrostatic latent image, and image flow occurs. On the other hand, if the resistance of the lubricant is too high, the lubricant in the form of fine powder is easily charged. Then, the fine powder of the lubricant aggregates, and the lubricant cannot be applied properly.
Therefore, by setting the resistance value of the lubricant to an appropriate value, the electrostatic latent image on the photoreceptor 2 is not destroyed, and the lubricant does not aggregate.

Further, the toner for forming a toner image in the exemplary form condition, the degree of circularity using the toner of 0.96 or more. This is because the toner with low circularity may have a poor transfer rate (the worst value is 85%). In this case, a portion covered with untransferred residual toner exists on the photoreceptor 2. If a large amount of toner is present on the photoreceptor 2, soiling will occur and uneven application of the lubricant will occur on the photoreceptor 2. Therefore, by using a spherical toner having a circularity of 0.96 or more, there is almost no untransferred toner and no scumming toner. Thereby, unevenness of the lubricant of the photosensitive member 2 due to the residual toner does not occur.

By the way, when realizing high image quality, it is important that the toner has a specific shape. When the average circularity is less than 0.95 and the irregular shape is too far from the spherical shape, the satisfactory transferability is obtained. And high quality images without dust are not obtained.
Here, a method for measuring the circularity of the toner and a method for measuring the particle size of the toner will be described. As a method for measuring the toner circularity, 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. . A toner with an average circularity of 0.95 or more, which is a value obtained by dividing the perimeter of an equivalent circle with the same projected area obtained by this method by the perimeter of the actual particle, is a high-definition image with a reproducibility of an appropriate density. It turned out to be effective in forming. More preferably, the average circularity is 0.960 to 0.998. This value can be measured as an average circularity by a flow type particle image analyzer FPIA-2000 (manufactured by Toa Medical Electronics Co., Ltd.). As a specific measurement method, 0.1 to 0.5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of water from which impure solids have been removed in advance. About 0.1 to 0.5 g. The suspension in which the sample is dispersed is obtained by performing dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser and measuring the shape and distribution of the toner with the above apparatus at a dispersion concentration of 3000 to 10,000 / μl. .
Next, the toner particle size is measured by using a Coulter Multisizer III (manufactured by Coulter Inc.) and connecting a personal computer (manufactured by IBM Corp.) with dedicated analysis software (manufactured by Coulter Inc.). Data analysis. The Kd value was set using standard particles of 10 μm, and the aperture current was set with an automatic setting. As the electrolytic solution, a 1% NaCl aqueous solution is prepared using primary sodium chloride. In addition, ISOTON-II (manufactured by Coulter Scientific Japan) can be used. As a measuring method, 0.1 to 5 ml of a surfactant, preferably alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and a weight average particle diameter was determined by measuring 50,000 counts of toner having a size of 2 μm or more using a 100 μm aperture tube.

If the surface of the photoconductor 2 is uneven, the uniformity of the lubricant on the photoconductor 2 decreases. Therefore, the use of amorphous silicon for the photoconductor 2 dramatically improves the smoothness of the photoconductor. As a result, the lubricant can be uniformly applied onto the photoreceptor 2.
FIG. 9 is a schematic configuration diagram for explaining a layer configuration of the amorphous silicon photosensitive member. In the electrophotographic photoreceptor 500 shown in FIG. 9A, a photoconductive layer 502 made of a-Si: H, X and having photoconductivity is provided on a support 501. An electrophotographic photoreceptor 500 shown in FIG. 9B includes a photoconductive layer 502 made of a-Si: H, X and having photoconductivity, and an amorphous silicon surface layer 503 on a support 501. It is configured. An electrophotographic photoreceptor 500 shown in FIG. 9C has a photoconductive layer 502 made of a-Si: H, X and having photoconductivity on a support 501, an amorphous silicon-based surface layer 503, and And an amorphous silicon based charge injection blocking layer 504. In the electrophotographic photoreceptor 500 shown in FIG. 9D, a photoconductive layer 502 is provided on a support 501. The photoconductive layer 502 includes a charge generation layer 505 made of a-Si: H, X and a charge transport layer 506, and an amorphous silicon-based surface layer 503 is provided thereon.

Further, in order to improve the smoothness of the surface of the photoreceptor 2, an organic photoreceptor (OPC) in which a filler is dispersed in the surface layer may be used as the photoreceptor 2.
In a photoconductor using only an organic photoconductor (OPC), the surface of the photoconductor is abraded because it is rubbed in a cleaning process to collect residual toner. At this time, if wear progresses rapidly, the surface of the photoreceptor often wears unevenly. As a result, irregularities are generated on the surface of the photoreceptor, and the lubricant cannot be uniformly applied onto the image carrier.
Therefore, an organic photoconductor (OPC) in which filler is dispersed in a surface layer with excellent hardness and the surface layer is reinforced is used, so the amount of wear is small over time, so that the surface of the image carrier is less likely to be uneven, and the lubricant is evenly applied. become able to.

  Further, in order to improve the smoothness of the surface of the photoreceptor 2, the photoreceptor 2 may use a cross-linked charge transport material such as an ABS resin for the surface layer. Since an ABS resin having excellent hardness is used, the amount of wear is small over time, so that the surface of the image bearing member is less likely to be uneven, and the lubricant can be applied uniformly.

Although FIG. 1 shows the tandem type image forming unit 1, the present invention is not limited to this. An image forming unit of a copying machine employing a revolver type instead of a tandem type image forming unit will be described with reference to FIG.
The revolver-type full-color image forming unit 1 sequentially develops toner images of a plurality of colors on one photoconductor 2 by switching the operation of the developing device 5.
Then, the color toner image on the intermediate transfer roller 6 is transferred to the recording paper P between the secondary transfer roller 7 and the transfer roller 9, and the recording paper P on which the toner image is transferred is conveyed to a fixing unit (not shown). Then, a fixed image is obtained.
On the other hand, the photosensitive member 2 on which the toner image is transferred to the intermediate transfer belt 6 is further rotated, and the toner remaining on the surface of the photosensitive member 2 is scraped off and removed by the cleaning unit 13, and then the static eliminator 8 removes static electricity. To do. After the photosensitive member 2 discharged by the photosensitive member discharging device 8 is uniformly charged by the charging roller 3 as a charging device, the next image formation is performed in the same manner as described above. The cleaning unit 13 is not limited to the one that scrapes the residual toner on the photoconductor 2 with a blade, and may be one that scrapes the residual toner on the photoconductor 2 with a fur brush, for example.

Next, FIG. 11 shows a schematic configuration in which the image forming unit 10 of FIGS. 1 and 2 is a process cartridge. In FIG. 11, 20 denotes the entire process cartridge, 2 denotes a photosensitive member, 3 denotes a charging means, 5 denotes a developing device, 13 denotes a cleaning means, 100 denotes a solid lubricant, and 150 and 151 denote lubricant application brushes. .
Among the above-described components such as the photoreceptor 2, the charging device 3, the developing device 5, the cleaning unit 13, the solid lubricant 100, and the lubricant application brushes 150 and 151, a plurality of components are integrated as a process cartridge. Combining and configuring. The process cartridge is configured to be detachable from a main body of an image forming apparatus such as a copying machine or a printer.
If a lubricant application member such as a lubricant application brush is installed separately from the photosensitive member, a positional shift is likely to occur in the installation. Therefore, by using a process cartridge that supports at least the photosensitive member 2 and the lubricant application brushes 150 and 151 in this way, the position of the lubricant supply means relative to the photosensitive member can be fixed. As a result, the lubricant can be stably applied to the photoreceptor.

Next, problems for each charging method of the charging device will be described. As for corona charging, the electrophotographic process often uses corona discharge at each portion such as a charging portion that uniformly charges the photosensitive member, but a product is generated by this corona discharge. Examples include ozone and nitrogen oxides. When ozone accumulates in the image forming apparatus at a high concentration, it oxidizes the surface of the photoconductor, causing a decrease in photosensitivity of the photoconductor and deterioration of the charging ability, resulting in deterioration of the formed image (reference: Toshifumi Meirin et al., “ Development of corona charger to reduce photoconductor degradation caused by ozone, "Journal of Electrophotographic Society, Vol. 31, No. 1, 1992). Further, there is a problem that deterioration of members other than the photoconductor is promoted and the life of the parts is reduced.
The cause of the image flow material is thought to be nitrogen oxides, but nitrogen oxides cause the following problems. Although it is known that nitrogen oxides are generated by discharge, nitrogen oxides react with moisture in the air to produce nitric acid, and react with metals and the like to form metal nitrates. Further, ammonium ions are simultaneously formed in the discharge region, and the ammonium ions react with nitrogen oxides to generate a compound. These products have high resistance under a low humidity environment, but react with water in the air under a high humidity environment, and become low resistance. Therefore, when a thin film of nitric acid or nitrate is formed on the surface of the photoconductor, an abnormal image such as an image is generated. This is because nitric acid and nitrate absorb moisture, resulting in low resistance, and the electrostatic latent image on the surface of the photoreceptor is broken.
Furthermore, since nitrogen oxides remain in place after being discharged without being decomposed into the air, the adhesion of the compounds generated from nitrogen oxides to the surface of the photoreceptor is not charged, that is, It also occurs during process pauses. This compound penetrates from the surface of the photoreceptor to the inside as time passes. This contributes to the deterioration of the electrostatic latent image. A method is adopted in which deposits on the surface of the photoreceptor are removed by scraping the photoreceptor little by little during cleaning. However, cost increases and deterioration problems with time occur, and this is not an essential solution.

By the way, as for the contact roller charger, a contact charging device that charges a photosensitive member by bringing a charging member into contact with the photosensitive member has been proposed and put into practical use. For example, a roller-shaped charging member is brought into contact with the photosensitive member and driven to charge the photosensitive member. Compared with the corona charging method used in the past, this contact charging method has advantages such as the generation amount of discharge products is extremely small, the applied voltage is low, the cost of power supply is reduced, and the design of electrical insulation is easy. have. Furthermore, problems due to ozone, nitrogen oxides and the like are reduced.
As the contact type roller charger, for example, as disclosed in Japanese Patent Laid-Open No. 63-7380, a roller-shaped charging member is brought into contact with the photosensitive member and driven to charge the photosensitive member. Are known.
By the way, in the contact type charging device, since the charging member is a rubber material, the roller in contact with the photosensitive member may be deformed when the copying machine is stopped for a long period of time. In addition, since rubber is a material that easily absorbs water, the electrical resistance fluctuates greatly with environmental changes.
Furthermore, rubber requires several kinds of plasticizers and activators in order to exert its elasticity and prevent deterioration, and in order to disperse the conductive pigment, a dispersion aid is often used. That is, since the surface of the photoreceptor is an amorphous resin such as polycarbonate or acrylic, it is very weak against the above-mentioned plasticizer, activator and dispersion aid.
In the contact charging method, a foreign object is caught between the charging member and the photosensitive member, and the charging member is contaminated to cause charging failure. When the roller is in direct contact with the photosensitive member, the photosensitive member is stored for a long time. Contamination, which may cause image defects such as horizontal stripes.
Further, when the charging member and the image carrier are in contact, the lubricant on the surface of the photosensitive member may be peeled off at the portion where the charging roller is in contact with the photosensitive member.

  As described above, the corona charging and the contact roller charging each have a problem that is difficult to reduce. In view of this, a minute gap is provided between the photosensitive member and the photosensitive member, and the proximity roller charging is performed to cause discharge in the adjacent space formed by the gap. By performing proximity roller charging, the amount of discharge products generated is extremely small compared to corona charging, the applied voltage is low, so the cost of the power supply is reduced, and electrical insulation design is easy to perform. Has advantages. Furthermore, problems due to ozone, nitrogen oxides and the like are reduced. Further, unlike contact roller charging, there is no possibility of causing problems such as deformation of the charging roller, contamination of the photoconductor, and peeling of the lubricant on the surface of the photoconductor because it does not contact the photoconductor. In this case, since the spacer that maintains the distance between the photoconductor and the charging roller contacts the surface of the photoconductor, it is better to apply a large amount of lubricant to the portion that contacts the spacer.

  By the way, the applied bias method includes a DC voltage and an AC superposition type. The method of applying a DC voltage is difficult in practical use due to problems such as variations in charging potential due to minute gap fluctuations and discharge stability. For this reason, when the AC superposition type is non-contact, it is considered to be a suitable method. However, although the AC superimposition method is stronger than the DC voltage method in terms of the stability of the charging potential and the stability of the discharge with respect to a minute gap variation, if the variation becomes too large, the stability is lost, and the abnormal image It becomes a cause.

The structure of the charging roller 3 is applied to an form status, the inventors have conducted the following experiments, we found the configuration of the preferred charging roller.

[Experiment 1]
In Experiment 1, the resistance of the spacer member was low, and a problem was observed when discharge occurred in a portion where the spacer member was close to the image carrier.
In order to lower the resistance value of the spacer member, a charging roller using a heat-shrinkable tube containing carbon as the spacer member was prepared.
An image was output from this roller under the following conditions.
(Experimental equipment and conditions)
Machine: IPSiO color 8000 remodeling machine (direct transfer type full color printer, charging device remodeling)
Charging device: non-contact, hard type charging roller gap in FIGS. 3 and 4: 50 μm
Spacer member: bias applied to charging of heat-shrinkable tube containing carbon by the method of FIG. 5: AC component: Vpp = 2.2 kV, f = 2 kHz,
DC component: -700V
When 200,000 images were output under the above conditions, the gap H in FIG. 3 decreased from 50 μm (initial) to 40 μm (after the run).
When the surface of the spacer member of the charging roller after paper output was observed, the image carrier was worn and had adhesiveness.
From this, it can be considered that when the resistance of the spacer member is low and discharge occurs in a portion where the spacer member is close to the image carrier, the image carrier is sputtered by the discharge, the image carrier is worn, and the gap is reduced. Therefore, it is understood that the spacer member must be a high resistance, that is, an insulating member. At this time, the volume resistivity of the spacer member is 10 ¹² Ω · cm or more.

この結果より、帯電ローラと像担持体の間のギャップが１２０μｍ以上になると、斑点状のムラが出力画像に現われることがわかった。よって、正常な画像を出力する、つまり帯電部において均一帯電を行うためには、ギャップを１００μｍ以下にする必要があることがわかる。 [Experiment 2]
In Experiment 2, the relationship between a minute gap between the roller and the image carrier and an abnormal image (spotted unevenness) was verified.
In order to investigate the frequency of occurrence of speckled abnormal images when the minute gap between the charging roller and the image carrier fluctuated, the following experiment was conducted. The experiment was performed in a normal environment.
(Experimental equipment and conditions)
Copy machine: IPSiO color 8000 remodeling machine (direct transfer type full color printer, charging device remodeled)
Charging device: bias applied to charging of non-contact and hard type charging roller in FIGS. 3 and 4: AC component: Vpp = 2.2 kV, f = 2 kHz,
DC component: -700V
Micro gap holding method: A polyethylene terephthalate (PET) tape was wound around both ends of the charging roller. (Thickness: 30, 50, 80, 100, 120, 150 μm).
Environmental conditions: 25 ° C, 65%
Output image: Halftone image Table 1 summarizes the output results of the images at this time.

From this result, it was found that when the gap between the charging roller and the image carrier is 120 μm or more, spotted unevenness appears in the output image. Therefore, it is understood that the gap needs to be 100 μm or less in order to output a normal image, that is, to perform uniform charging in the charging portion.

[Experiment 3]
In Experiment 3, the gap dependence of the charging potential characteristics of DC charging and AC charging was verified.
In order to investigate the relationship between the voltage applied to the charging roller and the charging potential of the photosensitive member when the minute gap between the charging roller and the image bearing member fluctuated, the following experiment was conducted. The experiment was performed in a normal environment.
(Experimental equipment and conditions)
Copy machine: IPSiO color 8000 remodeling machine (direct transfer type full color printer, charging device remodeled)
Charging device: Non-contact and hard type charging roller micro gap maintaining method of FIGS. 3 and 4 Method: Polyethylene terephthalate (PET) tape was wound around both ends of the charging roller. (Thickness: 0, 0.03, 0.05, 0.08 mm).
Environmental conditions: 25 ° C, 65%
Output Image: Halftone Image FIG. 12 shows the relationship between the applied voltage Vdc and the charging potential when DC charging is performed using the gap as a parameter.
From FIG. 12, it can be seen that when the gap is increased, the plot is shifted to the right without changing the slope of the graph. Charge starting voltage Vth (1501) is, Ri you, depending on the gap, is the is the discharge starting voltage spread the gap increases. In other words, when the gap becomes wide, the charged potential cannot be kept the same unless the applied voltage is increased. As a result, when the charging roller is non-contact, there is a possibility that the gap between the charging roller and the image carrier varies due to vibrations from the machine or environmental changes. However, as shown in FIG. Changes. Therefore, when DC charging is performed, the charging potential changes unless the applied bias is adjusted.

Next, FIG. 13 shows the relationship between Vpp and charging potential when AC charging is performed. From FIG. 13, the charging potential is proportional to Vpp until Vpp is twice the discharge start voltage Vth (1601). When Vpp is twice or more than Vth, the charging potential becomes constant. When the gap changes, the plot of the relationship between Vpp and the charging potential changes when Vpp is twice or less than Vth. However, when Vpp is twice or more than Vth, the charging potential becomes a certain constant value regardless of the gap. That is, in the case of AC charging, by setting Vpp to twice or more than Vth, the charging potential can be kept constant even when the gap changes.
If there are gaps in a static-roller and the image bearing member, who was AC charging it is possible to obtain a stable charging.

By the way, the relationship between the gap and the charging potential can be explained by Paschen's law. In particular, when the gap is in a certain range, the discharge start voltage Vth (V) and the gap d (μm) are expressed by the following empirical formula (1).
Vth = 6.2 × d + 312 40 ≦ d ≦ 120 (μm) (1)
From the above equation (1), the discharge start voltage varies as the gap varies. From the equation, it can be seen that the discharge start voltage Vth changes by 6.2 V when the gap d changes by 1 μm.
Further, the charging potential V is V = V0−Vth (2) where the applied voltage V0 is assumed.
It is expressed. From equations (1) and (2), it can be seen that when the gap varies, the charging potential varies and the variation range is 6.2 V / μm.

表２より、帯電ローラが硬質の材料からなる場合は、環境を変化させてもギャップが変化しないが、ゴムローラの場合は、硬質環境の下でギャップが非常に狭くなってしまうことが分かる。ギャップが狭くなると言うことは、接触している可能性も考えられるため、帯電ローラのトナー汚れが発生してしまう可能性がある。よって、帯電均一性を維持するためにも、帯電ローラは、ギャップ維持が確実となるハードタイプのものを用いるのがよい。また、帯電ローラのトナー汚れを避けるという点では、転写効率の高い球形トナーを用いることも有効である。 [Experiment 4]
In Experiment 4, a problem was observed when a rubber roller (roller with low hardness, JISA 70-80) was used as the charging roller. Considering the working environment, it is considered that the use environment limit where moisture absorption is most promoted in the office is about 30 ° C. and about 80%. Similarly, the low humidity environment limit assumed in an office is considered to be about 20% at a high temperature of about 30 ° C. The present invention is conceived to provide a charging device that is excellent in quality over time under such environmental conditions.
When a small gap is formed as shown in FIG. 3 under the conditions of 30 ° C. and 20% where the influence of moisture absorption is small, if a conventional rubber charging roller is used, the moisture absorption of the middle resistance layer is caused by moisture absorption as shown in FIG. Since the gap member cannot be extended due to expansion, the charging member and the image carrier may come into contact with each other. Further, considering the case where the hygroscopic portion is concentrated in the center due to the airflow design of the apparatus, contact occurs at that portion as shown in FIG. The occurrence of contact as in (a) can be reduced by imparting the stretchability of the gap member, but in the event that contact as in (b) occurs, it cannot be reduced by the method described above.
Here, Table 2 shows the relationship between the environment and the gap when rubber rollers and hard rollers are used.

From Table 2, it can be seen that when the charging roller is made of a hard material, the gap does not change even when the environment is changed, but in the case of a rubber roller, the gap becomes very narrow under a hard environment. When the gap is narrowed, there is a possibility that the gap is in contact with each other, so that there is a possibility that the toner on the charging roller is stained. Therefore, in order to maintain the charging uniformity, it is preferable to use a hard roller that can reliably maintain the gap. In order to avoid toner contamination on the charging roller, it is also effective to use spherical toner with high transfer efficiency.

As described above, according to the present embodiment forms condition, a lubricant rubbing member, lubricants lubricant is coated member on two lubricant applying brush 150 and 151, the second lubricant from the first lubricant applying brush 150 When the lubricant is delivered to the application brush 151, the lubricant is rubbed at the contact portion between the first lubricant application brush 150 and the second lubricant application brush 151. The lubricant is pulverized by rubbing. As a result, the lubricant applied to the photoreceptor 2 from the second lubricant application brush 151 is applied in a fine powder state. By applying the fine powder on the photoconductor 2, the lubricant has a layered structure on the photoconductor 2 and can exhibit lubricity. Further, when the lubricant exhibits lubricity, the cleaning blade 13b can exhibit its cleaning performance.
Further, by providing a solenoid mechanism (not shown) in the solid lubricant 100 so that the solid lubricant 100 can be brought into contact with and separated from the lubricant application brush 150, the amount of lubricant applied to the photoreceptor 2 can be changed. I can do it. Then, by controlling the contact / separation mechanism, the application state of the lubricant from the lubricant application brush 150 to the photoreceptor 2 is controlled from continuous operation to intermittent operation, thereby controlling the amount of lubricant applied to the photoreceptor 2. I can do it.
Further, by using the proximity charging type charging roller 3 as the charging means of the photoconductor 2, the power consumption can be reduced as compared with the charger type, and the contact type photoconductor is not contaminated. When using a system in which discharge is caused in the space between the charging roller 3 and the photoconductor 2 to charge the photoconductor 2, the surface of the photoconductor 2 is likely to deteriorate. The effect as a protective substance of the photoreceptor 2 is also great.
Also, by using a lubricant having a volume resistivity of 1.0 × 10 ^{9 to} 1.0 × 10 ¹⁵ Ω · cm, image flow on the photoreceptor 2 and aggregation of the lubricant can be prevented. I can do it.
Further, by using toner having a circularity of 0.96 or more, unfixed toner hardly remains on the photoconductor 2, so that there is no background stain, and the lubricant is applied on the photoconductor 2. Unevenness can be prevented.
In addition, by supporting the lubricant application brushes 150 and 151 as the lubricant supply means together with at least the photosensitive member 2 to form a process cartridge, it is possible to prevent defective application of the lubricant due to the positional deviation between the photosensitive member and the lubricant application brush. I can do it.

[ Example of implementation ]
Next, instead of a configuration in which a plurality of lubricant application brushes are provided as shown in FIG. 8 and the lubricant is transferred from the brush to the brush, all of the plurality of lubricant application brushes are in contact with the photoreceptor 2 and the lubricant. application brush together also describes a variant embodiment configured to abut.
Figure 15 is a schematic diagram of a variant embodiment. As shown in FIG. 15, the lubricant application brushes 152 and 153 that are in contact with each other are in contact with both the photoreceptor 2 and the solid lubricant 100. As shown in the figure, the rotation direction of the lubricant application brushes 152 and 153 is in contact with other lubricant application brushes on the downstream side of the rotation direction of the lubricant application brush from the location where the lubricant is supplied from the solid lubricant 100. Rotate to. By rotating in this way, the lubricant that is supplied from the solid lubricant 100 to the lubricant application brushes 152 and 153 and adheres to the lubricant application brush reliably passes through the contact portions of the two lubricant application brushes. It will be. When passing through the contact portion of the lubricant application brush, a shearing force is applied to the lubricant adhering to the lubricant application brush, and the particle size of the powder is reduced. Applied to the body. Lubricant applying brush 152 and 153 of the exemplary modification, like the lubricant applying brush 150 and 151 of the exemplary shaped state, also serves the role of both the lubricant application member and the lubricant scraping member.

[ Reference Modification 1 ]
Then, the lubricant applying brush is lubricant application member, the reference modification 1 is a structure in which a rubbing plate which is lubricant rubbing member will be described.
FIG. 16 is a schematic diagram of Reference Modification 1 . As shown in FIG. 16, a flicker 155 as a rubbing plate is provided in contact with the lubricant application brush 154 in a region where the lubricant application brush 154 carries and conveys the lubricant from the solid lubricant 100 to the photoreceptor 2. It is a configuration.
The lubricant that has adhered to the lubricant application brush 154 from the solid lubricant 100 comes into contact with the lubricant application brush 154 and the flicker 155 when the lubricant application brush 154 rotates, so that the lubricant adheres to the lubricant application brush. A shearing force is applied to the agent. As a result, the lubricant becomes a fine powder and is applied to the photoreceptor in a state where the particle size is small.
As the material of the flicker 155, it is desirable that the weight of the member is light, and considering the ease of processing, it is suitable to use a resin such as PET or acrylic.

[ Reference modification 2 ]
Next, a reference modification example 2 in which a lubricant heating member is provided on a lubricant application brush that is a lubricant application member will be described.
FIG. 17 is a schematic diagram of Reference Modification 2 . As shown in FIG. 17, a heater 157 as a heating member is provided inside the lubricant application brush 156. Heat of the heater 157 is transmitted to the lubricant adhering to the lubricant application brush 156 via the lubricant application brush. As a result, it is considered that the lubricant powder is more likely to break and become finer than when used at room temperature, and can be applied to the photoreceptor with a small particle size. However, at this time, the temperature of the heater 157 must be lower than the melting point of the lubricant. This is because if the heater temperature is higher than the melting point of the lubricant, the lubricant may melt on the lubricant application brush 156 and stick to the lubricant application brush 156.
In FIG. 17, the heater 157 is provided inside the lubricant application brush 156, but the arrangement of the heater is not limited to such a configuration, and the lubricant application brush 156 is externally disposed on the lubricant application brush 156. You may provide in the position which heats a lubricant.
Further, as a configuration for pulverizing the lubricant on the lubricant application member, a configuration combining the configurations shown in FIGS. 8, 15, 16, and 17 may be employed.

[ Reference form 1 ]
Next, Reference Embodiment 1 in which a lubricant particle diameter regulating means is provided in the lubricant container will be described. The points other than the point of providing the lubricant micronized means, since the common practice shaped on purpose, description of the features common will be omitted.
FIG. 18 is a schematic configuration diagram of the image forming unit 10 of the copying machine according to the first embodiment . Description of the points common to the image forming unit 10 described with reference to FIG 2. FIG shaped state also the configuration of the imaging units will be omitted. The difference is that the lubricant containing portion is provided with a bar-shaped solid powder lubricant 110 that is bonded to each other with a binding force weaker than an external force and that has one unit of 1 μm or less as a lubricant particle size regulating means. It is in place. The powdered solid lubricant 110 is shaved with a lubricant application brush 160 as an application supply member and applied onto the surface of the photoreceptor 2. The powder solid lubricant 110 is scraped by the shearing force of the lubricant application brush 160 to become powder. At this time, since the powdered solid lubricant 110 is a solid lubricant having a structure that easily becomes a fine powder having a bonding unit of 1 μm or less, the scraped powder becomes a fine powder of 1 μm or less. By using such a powder solid lubricant 110, the lubricant is brushed by the lubricant application brush 160, the particle size of the lubricant becomes small, and the lubricity is exhibited on the photoreceptor 2. A solid powder lubricant with a particle size of 1 μm or less is formed by melting the lubricant once and solidifying it while controlling the cooling rate (for example, rapidly cooling). I think I can do it. Alternatively, the lubricant bar may be formed into a roller shape and used while being rotated.

By the way, in FIG. 18, the lubricant application brush 160 as the lubricant supply means is installed on the upstream side of the cleaning blade 13b in the photosensitive member rotation direction.
For example, as shown in FIG. 25, the lubricant application by the lubricant application brush 160 may be performed downstream of the cleaning blade 13b.
Further, the cleaning may be configured with only the cleaning brush 13a and only the cleaning blade 13b.
Further, as shown in FIG. 26, a blade 161 for applying a lubricant with a lubricant application brush 160 and then uniformly leveling the lubricant may be provided.

As described above, according to the first embodiment , a lubricant having an appropriate particle size is applied to the photoreceptor 2 by using the powder solid lubricant 110 as the lubricant particle size regulating means in the lubricant container. be able to. Thereby, the cleaning property of the cleaning member can be exhibited while maintaining the lubricating action of the photoreceptor 2. Further, since the lubricant is in a solid state until it is scraped off by the lubricant application brush 160, it is possible to prevent the fine powder from flying in the copying machine and improve the handling of the lubricant.

[ Reference modification 3 ]
Next, a lubricant container containing fine powder lubricant is provided in the lubricant container, and a supply port for supplying the lubricant from the lubricant container to the lubricant supply means as a lubricant particle size regulating means. Reference modification 3 having a fine mesh is described.
FIG. 19 is a schematic diagram of Reference Modification 3 . Reference numeral 111 in FIG. 19 denotes a lubricant container that contains a lubricant to be supplied to the lubricant application brush 160 serving as a lubricant supply means, and has a fine mesh at a supply port that supplies the lubricant to the lubricant application brush 160. Is provided. The mesh size varies depending on the particle size of the fine powder lubricant contained therein. However, in Reference Modification 3 , the mesh size is 2 to reduce the particle size of the lubricant to 1 μm or less. It seems that ~ 3 μm is suitable. If the particle size of the fine powder lubricant can be made finer, the mesh size will be made finer accordingly. As described above, by using the lubricant container 111 having the mesh provided at the supply port, only the lubricant having a small particle diameter is supplied to the lubricant application brush 160 and supplied to the photoreceptor 2 by the mesh. Thus, the lubricant can exhibit lubricity on the photoreceptor 2, and the cleaning blade 13b can exhibit cleaning properties.

[ Reference modification 4 ]
Next, a description will be given of a reference modification example 4 in which a porous sponge for holding a lubricant is provided as a lubricant particle diameter regulating means in the lubricant container.
FIG. 20 is a schematic diagram of Reference Modification 4 . Reference numeral 112 in FIG. 20 denotes a porous lubricant holding sponge soaked with a lubricant. As a method of soaking the lubricant in the sponge, the sponge member is soaked in a melted state, and this is cooled to soak the lubricant in the sponge. Alternatively, a sponge may be put into a fine powder lubricant and pressed to soak the lubricant into the holes of the sponge and hold it.
By soaking the lubricant into the sponge, it is considered that the lubricant having a large particle diameter is caught inside the sponge and is hardly supplied to the lubricant supply brush 160.
In FIG. 20, the lubricant holding sponge 112 is drawn in a box shape, but the shape is not limited to this, and the lubricant holding sponge may be formed in a roller shape and used while being rotated.

[ Reference modification 5 ]
Next, Reference Modification 5 will be described, which is a configuration in which a brush 113 having brush fibers provided with a large number of minute irregularities is provided on the surface of the lubricant container that holds the lubricant.
FIG. 21 is a schematic diagram of Reference Modification 5 . Reference numeral 113 in FIG. 21 denotes a lubricant holding brush in which a lubricant is infiltrated into a brush member having brush fibers provided with many minute irregularities on the surface thereof. As a method for soaking the lubricant into the brush member, the brush member is soaked in a melted state, and this is cooled so that the lubricant is soaked into the brush. Alternatively, the lubricant may be infiltrated and held in minute irregularities on the surface of the brush fiber by pressing the brush member in a fine powder lubricant.
Examples of brush fibers having minute irregularities on the surface include porous zeolite and carbon fibers that form a single brush fiber formed by nanometer-order minute fibers.
By soaking the lubricant in a brush with minute irregularities, only the lubricant with a small particle size that can be held with minute irregularities is held by the brush, and only the lubricant with a small particle size is lubricated. It seems that the agent will be supplied to the agent supply brush 160.
Further, the lubricant holding brush 113 may be formed in a roller shape and used while being rotated.

[ Reference modification 6 ]
Next, Reference Modification 6 will be described, which is a configuration in which a low humidity maintaining means is provided in the lubricant accommodating portion in order to make the surrounding space where the lubricant is present a low humidity.
FIG. 22 is a schematic diagram of Reference Modification 6 . The periphery of the lubricant is sealed with a sealed container 600, and silica gel 700 is disposed for dehumidification as a low humidity maintaining means.
If there is moisture in the lubricant container, the fine powder lubricant will aggregate. In addition, when there is moisture, when the lubricant is scraped off by the application member, it does not become a fine powder but is transferred to the application member in a state where the particle size is large.
Therefore, by providing silica gel 700 as a low humidity maintaining means in the lubricant container, the fine powder does not condense with moisture and is scraped with the lubricant application brush 160 as the lubricant supply means. can do.
Therefore, a lubricant having an appropriate particle size can be applied on the photosensitive member 2, and the cleaning performance of the cleaning blade 13b as a cleaning member can be exhibited while maintaining the lubricating action of the photosensitive member 2.
Further, the low humidity maintaining means is not limited to the one provided with a dehumidifying agent such as silica gel, and a heater 701 as a heating means may be provided as shown in FIG. When using a heater, use it below the melting temperature of the lubricant.

[ Reference Modification 7 ]
Next, a description will be given of a reference modification example 7 in which the lubricant container is provided with a container vibrating member that vibrates so that the lubricant does not aggregate.
FIG. 24 is a schematic configuration diagram of Reference Modification 7 . Here, the vibration member 703 is provided in the lubricant container 115 that stores the fine powder lubricant. Examples of the vibration member include a vibrator motor and a piazo element.
If the lubricant is contained in the form of fine powder, it will aggregate over time. Therefore, by providing the vibrating member 703 in the lubricant container 115 and vibrating the lubricant, it is possible to prevent the lubricant from being loosened and causing aggregation.
In the reference modification example 7 , it is not necessary to always operate the vibration member during operation, and the amount of lubricant supplied may be controlled by arbitrarily controlling the vibration time. For example, the operation is performed for 1/10 of the drum rotation time, the operation is performed only when the switch is turned on, and the operation is performed for the time that the drum rotates once when 200 sheets are printed.
If the fine powder continues to vibrate, there is a risk that the powder will rise and soil the inside of the machine. Therefore, the lubricant is vibrated to the extent that the fine powder lubricant does not aggregate. Thereby, aggregation of the lubricant can be prevented without polluting the interior with the fine powder lubricant.

[ Reference form 2 ]
Next, Reference Embodiment 2 will be described in which lubricant finely pulverizing means is disposed against the surface of the image carrier on the downstream side in the moving direction of the image carrier surface of the lubricant supply means. The points other than the point of providing the lubricant micronized means, since the common practice shaped on purpose, description of the features common will be omitted.
FIG. 27 is a schematic configuration diagram of the image forming unit 10 of the copying machine according to the second embodiment . The lubricant pulverizing means in FIG. 27 uses a blade-shaped lubricant pulverizing blade 800, and the counter direction with respect to the image carrier (the angle formed by the blade and the image carrier is downstream in the rotation direction of the image carrier). To spread out). By applying in this way, particles larger than a predetermined particle size (hereinafter referred to as coarse powder) among the particles of the lubricant are dammed so as not to go downstream.
However, fine powder that is smaller than a predetermined particle size cannot be dammed. When the dammed coarse powder and fine powder pass through the blade, the lubricant is supplied as a uniform film on the image carrier. At this time, the particle diameter of the lubricant that has passed through the blade is desirably 1 μm or less. In addition, the method of hitting the blade in the counter direction is excellent in that the coarse powder is dammed up.
Lubricant powder having a large particle size does not exhibit sufficient lubricity on the photoreceptor, and deteriorates the cleaning performance of the image bearing member by the cleaning member. Therefore, a lubricant is carried on the photoreceptor with an appropriate particle size. Further, after being supplied as a fine powder, it is uniformly leveled on the surface of the image carrier to prevent problems such as deterioration of the photosensitive member due to the proximity charging means.

The lubricant fine powder blade 800 may be made of the same material as the cleaning blade 13b. That is, a known material such as polyurethane rubber, silicone rubber, nitrile rubber, or chloroprene rubber may be used as the material. The rebound resilience is preferably 20 to 80%, the thickness is 1 to 6 mm , and the contact angle with the image carrier is preferably about 15 to 45 °.
Further, as shown in the figure, the position of the lubricant pulverizing blade 800 is preferably the downstream side of the lubricant application brush 160 as the lubricant supply means and the upstream side of the static elimination device 8, but the static elimination device 8 is located on the cleaning blade 13b. It may be downstream and upstream of the lubricant application brush 160.
Further, when both the lubricant application brush 160 and the lubricant pulverizing blade 800 as the lubricant supply means are arranged on the upstream side of the charging device 8, problems such as deterioration of the photoreceptor 2 due to proximity charging are prevented or reduced. Is desirable. However, only the lubricant pulverizing blade 800 serving as the lubricant pulverizing means may be disposed on the downstream side of the charging device 8. At this time, as compared with the case where the lubricant pulverizing blade 800 is provided on the upstream side of the charging device 8, there is an inferior point in terms of preventing problems due to proximity charging.

In FIG. 27, the lubricant pulverizing blade 800 is applied in the counter direction with respect to the rotation direction of the photosensitive member 2, but the trailing direction (the angle formed by the blade and the image carrier is downstream in the rotation direction of the image carrier). You may apply to
FIG. 28 is a schematic configuration diagram of a configuration in which the blade is applied to the image carrier in the trailing direction. In this way, by applying the lubricant finely pulverizing blade in the trailing direction, it is easier to form the lubricant film on the image carrier as compared with the counter direction. Here, the blade material, thickness, and the like can be the same as those of the counter-type blade.

As described above, according to the second embodiment , by providing the lubricant fine powder blade 800, the coarse powder applied to the photoreceptor 2 is dammed, and the lubricant particle size downstream of the blade is set to a predetermined particle size. It can be as follows. By setting the diameter of the lubricant to a predetermined particle size or less, the lubricant exhibits lubricity on the photoreceptor 2 and can also improve the cleaning performance of the cleaning blade 13b.

[ Reference modification 8 ]
Next, reference modification 8 of a configuration using a brush instead of the lubricant pulverizing blade 800 of FIG. 27 will be described.
FIG. 29 is a schematic configuration diagram of Reference Modification 8 . The difference from FIG. 27 is that a lubricant pulverizing brush 801 is provided as the lubricant pulverizing means.
In this reference modification example 8 , when the lubricant fine powder brush 801 rotates, the coarse powder of the lubricant on the surface of the photoconductor 2 is rubbed to be fine powder. The rotational direction of the lubricant pulverizing brush 801 is preferably clockwise in the same way as the rotation direction of the image carrier in order to remove the coarse powder of the lubricant, but is opposite to the rotation direction of the image carrier, that is, counterclockwise. It may be rotated. When rotating counterclockwise, it is better to change the speed of the brush tip relative to the speed of the surface of the image carrier. If the speed of the surface of the image carrier is V1, the speed V2 of the brush tip is The range of the following formula is preferable.
0.5 × V1 ≦ V2 ≦ 5.0 × V1 (where V1 ≠ V2) (3)
When rotating clockwise, there is no particular problem within the range of the above formula (3).
The density of the brush is preferably 2000 / cm ² or more and 10,000 / cm ² or less, and more preferably 3000 / cm ² or more and 8000 / cm ² . The lower limit of the above range is a value determined based on the result of no abnormal image appearing on the photoreceptor 2 in the experiment. The upper limit of the above range only indicates a manufacturing limit, but manufacturing technology will increase in the future, and higher densities may be possible. Therefore, the upper limit is not particularly limited. In addition, it is desirable that the charging polarity of the brush is more negative than that of the photoreceptor 2. This is because the photosensitive member 2 is negatively charged and the lubricant is easily negatively charged, so that the lubricant is attracted to the brush when the charging polarity of the brush is positive. That is, it is possible to prevent the supply to the photosensitive member 2 from being unable to be supplied or the supply amount from being reduced even though the supply to the photosensitive member 2 is desired.

[ Reference modification 9 ]
Next, reference modification 9 in which a roller-shaped lubricant pulverizing roller 802 is provided as the lubricant pulverizing means will be described.
FIG. 30 is a schematic configuration diagram of Reference Modification 9 . In this reference modification 9 , the lubricant fine powder roller 802 rotates, so that the coarse powder of the lubricant on the surface of the photoreceptor 2 is rubbed and finely divided. As the material of the roller, metals such as stainless steel and mild steel and reinforced plastics are used for the core metal, and as the rubber material outside the core metal, known materials such as polyurethane rubber, silicone rubber, nitrile rubber, and chloroprene rubber are used. Materials are good. Furthermore, a coating layer on which the toner or lubricant is difficult to adhere may be provided on the surface layer of the rubber material. The characteristics required as the material of the roller are not only that the secretion (oil) from the inside does not ooze out, but also that the quality of the roller is small and the toner and lubricant are difficult to adhere.
The rotation direction of the roller is preferably different from that of the image carrier, but may be rotated in the same direction (clockwise). The speed of the roller surface may be in the range of equation (3).

[ Reference modification 10 ]
Next, reference modification 10 in which a belt-shaped lubricant pulverization belt 803 is provided as the lubricant pulverization means will be described.
31 and 32 are schematic configuration diagrams of Reference Modification Example 10. FIG. In this reference modification example 10 , when the lubricant fine powder belt 803 rotates, the coarse powder of the lubricant on the surface of the photosensitive member 2 is rubbed to be fine powder.
FIG. 31 shows a structure in which one roller side of an endless belt wound around two rollers is brought into contact with the photosensitive member 2. 32 employs a structure in which an endless belt is rotatably supported by three rollers, and two of the rollers are brought into contact with the photosensitive member 2 in order to increase the contact area with the photosensitive member 2. . By adopting such a structure, the coarse powder of the lubricant is reduced as compared with the structure of FIG. 31, and the supply of the lubricant to the photoconductor 2 is accelerated.
The rotation direction of the belt may be configured such that the surface of the endless belt moves along the moving direction of the image carrier surface, or the surface of the endless belt moves against the moving direction of the image carrier surface. It does not matter if it is configured. The moving speed of the belt surface may be in the range shown in Equation (3). In addition, the belt configuration preferably includes at least three layers of a base layer, an elastic layer, and a surface layer, but is not limited to this configuration. For example, an elastic layer may be provided on the support roller side in a two-layer configuration of a base layer and a surface layer.
The belt may be driven from a roller away from the image carrier, but may be driven from a roller in contact with the other photoreceptor 2.

In the configuration in which the lubricant on the photoconductor 2 is pulverized using the rotating body as in Reference Modifications 8 to 10 described above, the particle size of the fine powder is adjusted by changing the surface speed of the rotating body. I can do it. For example, when the surface speed of the rotating body is increased, the opportunity for the lubricant to be rubbed increases, so that a smaller fine powder can be obtained.

By the way, the embodiment , the embodiment modification , the reference embodiment 1 , the reference embodiment 2 and the respective reference modifications are different in the installation position of the pulverizing means, so that a plurality of embodiments , modifications , A reference form or a reference modification may be applied.

Schematic diagram of an image forming unit of the image forming apparatus according to an exemplary shape state. Schematic diagram of the image forming unit according to the embodiment form state. Schematic of a charging roller. FIG. 3 is an explanatory diagram of a minute gap between a charging roller and a photosensitive member. Explanatory drawing of the spacer mounting method of a charging roller. Explanatory drawing of the spacer mounting method of a charging roller. Explanatory drawing of the spacer mounting method of a charging roller. Schematic diagram of lubricant supply means according to the embodiment form state. Explanatory drawing of the layer structure of an amorphous silicon photoconductor. FIG. 2 is a schematic configuration diagram of an image forming unit of a copying machine adopting a revolver type. Schematic view of the process cartridge according to an exemplary shape state. The relationship diagram of the applied voltage and charging potential at the time of DC charging. The relationship diagram of the applied voltage at the time of AC charging, and a charging potential. Schematic configuration diagram explaining the state of hygroscopic expansion of a charging roller made of a rubber roller The schematic diagram of the lubricant supply means which concerns on the implementation modification. The schematic diagram of the lubricant supply means which concerns on the reference modification 1. FIG. The schematic diagram of the lubricant supply means which concerns on the reference modification 2. FIG. FIG. 3 is a schematic configuration diagram of an image forming unit according to Reference Embodiment 1 . FIG. 10 is a schematic diagram of an image forming unit according to Reference Modification 3 . FIG. 10 is a schematic diagram of an image forming unit according to Reference Modification 4 . FIG. 10 is a schematic diagram of an image forming unit according to Reference Modification 5 . FIG. 10 is a schematic diagram of an image forming unit according to Reference Modification 6 . FIG. 10 is a schematic diagram of an image forming unit according to Reference Modification 6 . FIG. 10 is a schematic diagram of an image forming unit according to Reference Modification 7 . FIG. 3 is a first arrangement example of an image forming unit according to Reference Embodiment 1 ; FIG. 6 is a second arrangement example of an image forming unit according to Reference Embodiment 1 ; The schematic block diagram of the image formation unit which concerns on the reference form 2. FIG. FIG. 5 is a second schematic configuration diagram of an image forming unit according to Reference Embodiment 2 . FIG. 10 is a schematic configuration diagram of an image forming unit according to Reference Modification 8 . FIG. 10 is a schematic configuration diagram of an image forming unit according to Reference Modification 9 ; FIG. 11 is a schematic configuration diagram of an image forming unit according to Reference Modification Example 10 . FIG. 10 is a second schematic configuration diagram of an image forming unit according to Reference Modification 10 ;

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 Photoconductor 3 Charging apparatus 4 Exposure apparatus 5 Developing apparatus 6 Intermediate transfer belt 7 Secondary transfer roller 8 Neutralizing apparatus 9 Primary transfer roller 10 Image forming unit 13 Cleaning device 13a Cleaning brush 13b Cleaning blade 100 Solid lubricant 110 Powder solid lubrication Agent 111 Lubricant container 112 Lubricant holding sponge 113 Lubricant holding brush 150 First lubricant application brush 151 Second lubricant application brush 152 Downstream lubricant application brush 153 Upstream lubricant application brush 154 Lubricant application with flicker Brush 155 Flicker 156 Heater-applied lubricant application brush 157 Heater 160 Lubricant application brush 201 Conductive substrate 202 Resistance layer 203 Thin layer 302 Spacer 303 Spring 500 Electrophotographic photoreceptor 501 Support body 502 Photoconductivity Layer 503 Amorphous silicon-based surface layer 504 Amorphous silicon-based charge injection blocking layer 505 Charge generation layer 506 Charge transport layer 600 Sealed container 700 Silica gel 701 Low-humidity holding heater 703 Vibration member

Claims (12)

An image carrier for carrying an electrostatic latent image;
A charging device for charging the surface of the image carrier;
A developing device for carrying a developer on a developer carrying member and transporting the developer to a developing region facing the image carrying member to develop a latent image on the image carrying member to form a toner image;
Cleaning means for removing residual toner remaining on the image carrier after the developed toner image is transferred to a transfer material;
An image having a lubricant supply means for supplying the lubricant from a lubricant accommodating portion for accommodating a lubricant on the surface of the image carrier after being transferred to the transfer material and before being charged by the charging device. In the forming device,
A plurality of lubricant supply brush you feed carrying-transportable the lubricant by the lubricant supply means is rotated,
At least one of the plurality of lubricant supply brushes is supplied with the lubricant from the lubricant container,
An image characterized in that the lubricant supplied from the lubricant container to the lubricant supply brush is supplied onto the surface of the image carrier after passing through a portion where the plurality of lubricant supply brushes rub against each other. Forming equipment. The image forming apparatus according to claim 1.
Image formation characterized in that the lubricant supplied from the lubricant container to the lubricant supply brush is supplied onto the surface of the image carrier via two or more lubricant supply brushes. apparatus. The image forming apparatus according to claim 1.
An image forming apparatus, wherein the plurality of lubricant supply brushes abut on the surface of the image carrier and apply the lubricant supplied from the lubricant container to the surface of the image carrier . The image forming apparatus according to any one of claims 1 to 3 ,
An image forming apparatus characterized in that the lubricant container can be brought into contact with and separated from the lubricant supply brush .   The image forming apparatus according to any one of claims 1 to 4,
An image forming apparatus comprising a lubricant heating member for heating the lubricant carried by the lubricant supply brush.   The image forming apparatus according to any one of claims 1 to 5,
A solid lubricant is disposed in the lubricant container,
At least one of the plurality of lubricant supply brushes is in contact with the solid lubricant and rotates to scrape off a portion of the solid lubricant, whereby the lubricant supply brush is lubricated to the lubricant supply brush. An image forming apparatus, wherein an agent is supplied. The image forming apparatus according to any one of claims 1 to 5,
Image forming apparatus characterized by the lubricant particle size specification system for supplying only fine powder-like lubricant into the lubricant supplying brush provided in the lubricant accommodating unit. The image forming apparatus according to any one of claims 1 to 7,
Image forming apparatus, characterized in that the lubricant lubricant micronized means to fine powder was placed against the image bearing member surface of the image bearing member surface movement direction downstream side of the lubricant supply brush . The image forming apparatus according to any one of claims 1 to 8 ,
An image forming apparatus, wherein the charging device is a charging device using a charging roller in contact with or close to the image carrier. The image forming apparatus according to any one of claims 1 to 9 ,
An image forming apparatus, wherein the lubricant has a volume resistivity of 1.0 × 10 ^{9 to} 1.0 × 10 ¹⁵ Ω · cm. The image forming apparatus according to any one of claims 1 to 10 ,
An image forming apparatus, wherein the toner forming the toner image has a circularity of 0.96 or more. The image forming apparatus according to any one of claims 1 to 11 ,
An image forming apparatus comprising: a process cartridge that supports the lubricant supply unit together with at least the image carrier and is detachable from a main body of the image forming apparatus.

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