JP2008129098A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which securely reduces deterioration of a cleaning blade and an image carrier, and occurrences of cleaning failure and filming, by stably and uniformly supplying a lubricant onto an image carrier even when a large quantity of toner accumulates on the edge part of the cleaning blade. <P>SOLUTION: The image forming apparatus comprises: the image carrier 21 driven in a predetermined direction in a state a toner image is carried; lubricant supply parts 25b and 45 for supplying the lubricant to the surface of the image carrier 21; and the cleaning blade 25a for cleaning the surface of the image carrier 21 while being brought into contact with the image carrier 21. Before the lubricant is supplied onto the image carrier 21 by the lubricant supply parts 25b and 45, the image carrier 21 is driven in the direction (indicated by the arrow) reverse to the predetermined direction with predetermined timing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine thereof, and in particular, supplies a lubricant onto an image carrier such as a photosensitive drum, a photosensitive belt, and an intermediate transfer belt. The present invention relates to an image forming apparatus provided with a lubricant supply unit.

  2. Description of the Related Art Conventionally, in an image forming apparatus using an electrophotographic system such as a copying machine or a printer, an adhering material such as non-transferred toner adhering to an image carrier such as a photosensitive drum is cleaned by a cleaning device, and an image carrier. A technique using a lubricant supply unit (lubricant supply device) for supplying a lubricant onto an image carrier in order to reduce wear of a cleaning blade or a cleaning blade is known (for example, see Patent Documents 1 to 3). .)

  Specifically, the untransferred toner remaining on the image carrier after the transfer process should be completely removed by a cleaning blade (cleaning device) that contacts the image carrier. However, when the cleaning blade deteriorates with time due to contact with the image carrier (abrasion), a cleaning failure may occur due to slipping through the gap between the cleaning blade where the untransferred toner is worn and the image carrier. Even when the cleaning blade is not deteriorated, when spherical toner or small-diameter toner is used, the toner enters a slight gap between the cleaning blade and the image carrier and eventually passes through the gap. A cleaning failure sometimes occurred. Furthermore, if toner or an external additive or paper dust contained in the toner slips through the gap between the cleaning blade and the image carrier, it adheres to the image carrier and forms a film. There was also.

  In response to such a problem, by applying a lubricant on the image carrier, the friction coefficient on the image carrier is reduced, so that deterioration of the cleaning blade and the image carrier is reduced. Since the removability of deposits such as untransferred toner adhering to the toner is improved, it is possible to suppress the occurrence of poor cleaning and filming over time.

  Specifically, in Patent Document 1 and the like, the lubricant supply unit (application member) includes a brush-like rotating member (brush portion) that is in sliding contact with the image carrier, and a solid lubricant that is in contact with the brush-like rotating member (lubricant molded body). ), A spring that urges the solid lubricant toward the brush-like rotating member, and the like. Then, the lubricant is gradually scraped off from the solid lubricant by the brush-like rotating member rotating in a predetermined direction, and the lubricant scraped off by the brush-like rotating member is applied (supplied) to the surface of the image carrier.

JP 2002-62737 A JP 2002-287567 A JP 2002-207397 A

  In the conventional image forming apparatus described above, when a large amount of toner stays at the edge portion of the cleaning blade (the tip portion that contacts the image carrier), the function of the lubricant supply portion is reduced, and the cleaning blade And image carrier deterioration, poor cleaning, and filming. Such a problem cannot be ignored particularly when spherical toner is used.

Details are as follows.
The lubricant supplied onto the image carrier by the lubricant supplier is uniformly thinned on the image carrier by the cleaning blade when passing through the contact position of the cleaning blade. However, when an image with a high image area ratio is printed continuously, a large amount of toner stays at the edge of the cleaning blade, and the lubricant supplied on the image carrier on the upstream side is removed. It was peeled off from the surface of the image carrier. Therefore, the lubricant supplied onto the image carrier is insufficient, and the coefficient of friction on the surface of the image carrier is increased. When the amount of lubricant supplied to the image carrier becomes extremely small, filming may occur on the surface of the image carrier, resulting in white spots on the output image, and a cleaning blade or image carrier. Deterioration of the body was accelerated and cleaning failure occurred.

  Here, if the lubricant supply amount is determined in accordance with the state in which the lubricant is difficult to be supplied to the image carrier, the amount of lubricant supplied to the image carrier is reduced when the toner does not stay at the edge of the cleaning blade. It becomes excessive. In such a case, the life of the solid lubricant may be shortened, or the lubricant that has passed through the cleaning blade may contaminate the charged part and the image carrier may not be sufficiently charged, resulting in a black streak image or the like. Will cause a malfunction.

  The present invention has been made to solve the above-described problems. Even when a large amount of toner stays at the edge of the cleaning blade, the lubricant is stably and uniformly distributed on the image carrier. An object of the present invention is to provide an image forming apparatus in which the deterioration of a cleaning blade and an image carrier, the occurrence of poor cleaning and filming are reliably reduced.

  An image forming apparatus according to a first aspect of the present invention includes an image carrier that is driven in a predetermined direction while carrying a toner image, and a lubricant supply unit that supplies a lubricant to the surface of the image carrier. And a cleaning blade that contacts the image carrier and cleans the surface of the image carrier, and before supplying the lubricant onto the image carrier by the lubricant supply unit, at a predetermined timing. The image carrier is driven in a direction opposite to the predetermined direction.

  The image forming apparatus according to a second aspect of the present invention is the image forming apparatus according to the first aspect, wherein the lubricant supply section is disposed on the opposite side of the cleaning blade. is there.

An image forming apparatus according to a third aspect of the present invention is the image forming apparatus according to the first or second aspect, wherein the cleaning blade and the image are driven with the reverse driving distance of the image carrier as Ra. When the distance from the contact position with the carrier to the position where the lubricant supply unit and the image carrier face each other is Rb,
Ra ≧ Rb
This relationship is established.

  An image forming apparatus according to a fourth aspect of the present invention is the image forming apparatus according to any one of the first to third aspects, wherein the image is not formed when a toner image is not formed on the image carrier. The carrier is driven in the reverse direction, and the lubricant is supplied onto the image carrier by the lubricant supply unit.

  According to a fifth aspect of the present invention, in the image forming apparatus according to the first to fourth aspects of the present invention, the lubricant supply section includes brush hairs that are in sliding contact with the image carrier. A brush-like rotating member provided around and a solid lubricant contacting the brush bristles of the brush-like rotating member, and supplying the lubricant onto the image carrier by rotating the brush-like rotating member It is.

  An image forming apparatus according to a sixth aspect of the present invention is the image forming apparatus according to the fifth aspect, wherein the solid lubricant is pressed against the brush-like rotating member at a pressure of 200 mN or more.

  According to a seventh aspect of the present invention, in the image forming apparatus according to the fifth or sixth aspect, the brush-like rotating member at a sliding contact position between the brush-like rotating member and the image carrier. The linear velocity ratio of the image carrier with respect to is set in the range of 0.8 to 1.2.

  An image forming apparatus according to an eighth aspect of the present invention is the image forming apparatus according to any one of the first to seventh aspects, wherein the linear pressure of the cleaning blade in contact with the image carrier is 0.1 to 10. It is set in the range of 0.5 N / cm.

  An image forming apparatus according to a ninth aspect is the invention according to any one of the first to eighth aspects, wherein the toner relating to the toner image has an average circularity of 0.93 to 1. .00.

  An image forming apparatus according to a tenth aspect of the present invention is the image forming apparatus according to any one of the first to ninth aspects, wherein the toner relating to the toner image has a shape factor SF-1 of 100 to 180. Thus, the shape factor SF-2 is formed to be 100 to 180.

An image forming apparatus according to an eleventh aspect of the present invention is the image forming apparatus according to any one of the first to tenth aspects, wherein the toner associated with the toner image has a length in a major axis direction as r1. When the length in the minor axis direction is r2, and the length in the thickness direction is r3,
0.5 ≦ r2 / r1 ≦ 1.0
0.7 ≦ r3 / r2 ≦ 1.0
r1 ≧ r2 ≧ r3
It is formed so that the following relationship is established.

The image forming apparatus according to a twelfth aspect of the present invention is the image forming apparatus according to any one of the first to eleventh aspects, wherein the toner relating to the toner image has silica fine particles added to the surface of the base particle. The silica fine particles are formed so as to have an average primary particle size of 50 to 300 nm and a bulk density of 0.3 g / cm ³ or more.

  According to a thirteenth aspect of the present invention, in the image forming apparatus according to any one of the first to twelfth aspects, the toner relating to the toner image has at least a functional group containing a nitrogen atom. A toner material liquid in which a polyester prepolymer, polyester, a colorant, and a release agent are dispersed in an organic solvent is formed by crosslinking or / and stretching reaction in an aqueous medium.

  An image forming apparatus according to a fourteenth aspect of the present invention is the image forming apparatus according to any one of the first to thirteenth aspects, wherein the cleaning blade and the lubricant supply unit are integrated. It is provided.

  According to a fifteenth aspect of the present invention, in the image forming apparatus according to any one of the first to thirteenth aspects, the image carrier, the cleaning blade, and the lubricant supply unit are integrated. The process cartridge is provided.

  In the present application, the “process cartridge” refers to a charging unit that charges the image carrier, a developing unit (developing device) that develops a latent image formed on the image carrier, and a cleaning on the image carrier. It is defined as a unit in which at least one of the cleaning unit (cleaning device) and the image carrier are integrated and detachably installed on the image forming apparatus main body.

  In the present invention, since the image carrier is driven in the reverse direction at a predetermined timing before the lubricant is supplied onto the image carrier by the lubricant supplier, a large amount of toner stays at the edge of the cleaning blade. In this case, it is possible to stably supply the lubricant evenly on the image carrier even if it has occurred, etc., and reliably reduce the deterioration of the cleaning blade and image carrier, and the occurrence of poor cleaning and filming. An apparatus can be provided.

Embodiment.
Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

First, the configuration and operation of the entire image forming apparatus will be described with reference to FIG.
In FIG. 1, 1 is an apparatus main body of a color copying machine as an image forming apparatus, 2 is a writing section (exposure section) that emits laser light based on input image information, and 20Y, 20M, 20C, and 20BK are colors (yellow, magenta). , Cyan, and black), 21 is a photosensitive drum as an image carrier accommodated in each of the process cartridges 20Y, 20M, 20C, and 20BK, 22 is a charging unit that charges the photosensitive drum 21, Reference numerals 23Y, 23M, 23C, and 23BK denote developing devices (developing units) that develop the electrostatic latent image formed on the photosensitive drum 21, and 24 denotes a toner image formed on the photosensitive drum 21 to the intermediate transfer belt 27. A transfer bias roller 25 for transferring, a cleaning device (cleaning unit) for collecting untransferred toner on the photosensitive drum 21, Show.

  In addition, 27 is an intermediate transfer belt on which toner images of a plurality of colors are transferred in an overlapping manner, 28 is a second transfer bias roller for transferring the toner image formed on the intermediate transfer belt 27 to the recording medium P, and 29 is an intermediate transfer belt. 27 is an intermediate transfer belt cleaning unit that collects untransferred toner, 30 is a conveyance belt that conveys a recording medium P on which a four-color toner image is transferred, and 32Y, 32M, 32C, and 32BK are developing devices 23Y and 23M. , 23C and 23BK, a toner replenishing unit for replenishing toner of each color, 51 a document conveying unit for conveying the document D to the document reading unit 55, 55 for a document reading unit for reading image information of the document D, 61 for transfer paper, etc. A paper feed unit for storing the recording medium P, and a fixing unit 66 for fixing an unfixed image on the recording medium P are shown.

Here, each of the process cartridges 20Y, 20M, 20C, and 20BK is a unit in which the photosensitive drum 21, the charging unit 22, and the cleaning device 25 (with a lubricant supply device installed therein) are integrated. is there. The process cartridges 20Y, 20M, 20C, and 20BK are exchanged with respect to the apparatus main body 1 in a predetermined exchange cycle. Similarly, the developing devices 23Y, 23M, 23C, and 23BK are also exchanged with respect to the apparatus main body 1 in a predetermined exchange cycle.
Image formation of each color (yellow, magenta, cyan, black) is performed on the photosensitive drum 21 in each of the process cartridges 20Y, 20M, 20C, and 20BK.

Hereinafter, an operation during normal color image formation in the image forming apparatus will be described.
First, the document D is transported from the document table in the direction of the arrow in the drawing by the transport roller of the document transport unit 51 and placed on the contact glass 53 of the document reading unit 55. Then, the document reading unit 55 optically reads the image information of the document D placed on the contact glass 53.

  Specifically, the document reading unit 55 scans the image of the document D on the contact glass 53 while irradiating light emitted from the illumination lamp. Then, the light reflected by the document D is imaged on the color sensor via the mirror group and the lens. The color image information of the document D is read for each RGB (red, green, blue) color separation light by the color sensor, and then converted into an electrical image signal. Further, an image processing unit (not shown) performs color conversion processing, color correction processing, spatial frequency correction processing, and the like on the basis of RGB color separation image signals, so that yellow, magenta, cyan, and black are processed. Get color image information.

  Then, the image information of each color of yellow, magenta, cyan, and black is transmitted to the writing unit 2. Then, laser light (exposure light) based on the image information of each color is emitted from the writing unit 2 toward the photosensitive drums 21 of the corresponding process cartridges 20Y, 20M, 20C, and 20BK.

On the other hand, each of the four photosensitive drums 21 rotates in a predetermined direction (clockwise in FIG. 1). First, the surface of the photosensitive drum 21 is uniformly charged at a position facing the charging unit 22 (a charging process). Thus, a charged potential is formed on the photosensitive drum 21. Thereafter, the surface of the charged photosensitive drum 21 reaches the irradiation position of each laser beam.
In the writing unit 2, laser light corresponding to the image signal is emitted from the light source corresponding to each color. The laser light is incident on the polygon mirror 3 and reflected, and then passes through the lenses 4 and 5. The laser light after passing through the lenses 4 and 5 passes through different optical paths for each of the yellow, magenta, cyan, and black color components (this is an exposure process).

  The laser beam corresponding to the yellow component is reflected by the mirrors 6 to 8 and then irradiated onto the surface of the photosensitive drum 21 of the first process cartridge 20Y from the left side of the drawing. At this time, the yellow component laser light is scanned in the rotation axis direction (main scanning direction) of the photosensitive drum 21 by the polygon mirror 3 that rotates at high speed. Thus, an electrostatic latent image corresponding to the yellow component is formed on the photosensitive drum 21 charged by the charging unit 22.

  Similarly, the laser beam corresponding to the magenta component is reflected by the mirrors 9 to 11 and then irradiated to the surface of the photosensitive drum 21 of the second process cartridge 20M from the left side of the paper, thereby causing an electrostatic latent image corresponding to the magenta component. An image is formed. The cyan component laser light is reflected by the mirrors 12 to 14 and then irradiated onto the surface of the photosensitive drum 212 of the third process cartridge 20C from the left side of the drawing to form a cyan component electrostatic latent image. The black component laser light is reflected by the mirror 15 and then irradiated on the surface of the photosensitive drum 21 of the fourth process cartridge 20BK from the left side of the paper, thereby forming an electrostatic latent image of black component.

Thereafter, the surface of the photosensitive drum 21 on which the electrostatic latent images of the respective colors are formed reaches positions facing the developing devices 23Y, 23M, 23C, and 23BK, respectively. Then, the respective color toners are supplied from the developing devices 23Y, 23M, 23C, and 23BK onto the photosensitive drum 21, and the latent image on the photosensitive drum 21 is developed (this is a developing step).
Thereafter, the surface of the photosensitive drum 21 after the development process reaches the position facing the intermediate transfer belt 27 after passing the position facing the photosensor 41 (see FIG. 2). Here, the transfer bias roller 24 is installed at each facing position so as to contact the inner peripheral surface of the intermediate transfer belt 27. Then, at the position of the transfer bias roller 24, the images of the respective colors formed on the photosensitive drum 21 are sequentially superimposed and transferred onto the intermediate transfer belt 27 (first transfer step).

Then, the surface of the photosensitive drum 21 after the first transfer process reaches a position facing the cleaning device 25. Then, the untransferred toner remaining on the photosensitive drum 21 is collected by the cleaning device 25 (this is a cleaning process).
Thereafter, the surface of the photosensitive drum 21 passes through a static elimination unit (not shown), and a series of image forming processes on the photosensitive drum 21 is completed.

On the other hand, the surface of the intermediate transfer belt 27 on which the images of the respective colors on the photosensitive drum 21 are transferred in an overlapping manner travels in the direction of the arrow in the drawing and reaches the position of the second transfer bias roller 28. Then, the full color image on the intermediate transfer belt 27 is secondarily transferred onto the recording medium P at the position of the second transfer bias roller 28 (this is the second transfer step).
Thereafter, the surface of the intermediate transfer belt 27 reaches the position of the intermediate transfer belt cleaning unit 29. Then, the untransferred toner on the intermediate transfer belt 27 is collected by the intermediate transfer belt cleaning unit 29, and a series of transfer processes on the intermediate transfer belt 27 is completed.

Here, the recording medium P at the position of the second transfer bias roller 28 is transported from the paper feeding unit 61 via the transport guide 63, the registration roller 64, and the like.
Specifically, the transfer paper P fed by the paper feed roller 62 from the paper feed unit 61 that stores the recording medium P passes through the conveyance guide 63 and is guided to the registration roller 64. The recording medium P that has reached the registration roller 64 is conveyed toward the position of the second transfer bias roller 28 in synchronization with the toner image on the intermediate transfer belt 27.

Thereafter, the recording medium P on which the full-color image is transferred is guided to the fixing unit 66 by the conveyance belt 30. In the fixing unit 66, the color image is fixed on the recording medium P at the nip between the heating roller 67 and the pressure roller 68.
Then, the recording medium P after the fixing process is discharged as an output image by the paper discharge roller 69 to the outside of the apparatus main body 1, and a series of image forming processes is completed.

Next, the image forming unit of the image forming apparatus will be described in detail with reference to FIG.
FIG. 2 is a cross-sectional view showing the image forming unit. The four image forming units installed in the apparatus main body 1 have substantially the same structure except that the color of the toner T used in the image forming process is different. Therefore, the alphabet of reference numerals in the process cartridge, the developing device, and the toner replenishing unit. (Y, M, C, BK) is omitted for illustration.
As shown in FIG. 2, the process cartridge 20 mainly contains a photosensitive drum 21 as an image carrier, a charging unit 22, and a cleaning device 25 integrally in a case 26.

Here, the photosensitive drum 21 as an image bearing member is a negatively charged organic photosensitive member, in which a photosensitive layer or the like is provided on a drum-shaped conductive support.
Although not shown, the photosensitive drum 21 has a conductive support as a base layer, an undercoat layer as an insulating layer, a charge generation layer and a charge transport layer as a photosensitive layer, and a protective layer (surface layer) sequentially. Are stacked.

  Referring to FIG. 2, the charging unit 22 is a charging roller formed by covering an outer periphery of a conductive metal core with an intermediate resistance elastic layer. A predetermined voltage is applied to the charging roller 22 from a power supply unit (not shown), thereby uniformly charging the surface of the opposing photosensitive drum 21.

  The developing device (developing unit) 23 mainly faces the first conveying screw 23b via the developing roller 23a facing the photosensitive drum 21, the first conveying screw 23b facing the developing roller 23a, and the partition member 23e. The second conveying screw 23c and a doctor blade 23d facing the developing roller 23a are configured. The developing roller 23a includes a magnet that is fixed inside and forms a magnetic pole on the circumferential surface of the roller, and a sleeve that rotates around the magnet. A plurality of magnetic poles are formed on the developing roller 23a (sleeve) by the magnet, and the developer G is carried on the developing roller 23a.

In the developing device 23, a two-component developer G composed of carrier C and toner T is accommodated. Here, in the present embodiment, a substantially spherical toner T (spherical toner) is used to improve the image quality.
Specifically, the toner T is formed so that the average circularity is 0.93 to 1.00. The “average circularity” is measured by a flow type particle image analyzer “FPIA-2000” (manufactured by Sysmex Corporation). Specifically, 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 9.5 g of a measurement sample (toner) is added. Thereafter, the suspension in which the toner is dispersed is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the dispersion liquid concentration is set to 3000 to 10000 / μl in the above-described analyzer. Then, the shape and distribution of the toner are measured.

The toner T is formed such that the shape factor SF-1 is 100 to 180 and the shape factor SF-2 is 100 to 180.
Here, the shape factor SF-1 indicates the ratio of the roundness of the toner shape, and can be expressed by the following equation.
SF-1 = {(MXLNG) ² / AREA} × (100π / 4)
In the above equation, MXLNG is the maximum length of a shape formed by projecting toner onto a two-dimensional plane, and AREA is a graphic area. When the value of SF-1 is 100, the shape of the toner is a true sphere, and becomes irregular as the value of SF-1 increases.
The shape factor SF-2 indicates the ratio of the unevenness of the toner shape, and can be expressed by the following equation.
SF-2 = {(PERI) ² / AREA} × (100 / 4π)
In the above equation, PERI is a perimeter of a figure formed by projecting toner onto a two-dimensional plane. When the value of SF-2 is 100, there is no unevenness on the toner surface, and as the value of SF-2 increases, the unevenness of the toner surface becomes more prominent.
Specifically, the shape factor is measured by taking a photograph of the toner with a scanning electron microscope “S-800” (manufactured by Hitachi, Ltd.) and using the image analysis apparatus “LUSEX3” (manufactured by Nireco). Analyzed and calculated.
By setting the toner shape factors SF-1 and SF-2 to 100 or more, it is possible to reduce the amount of toner entering the slight gap between the cleaning blade 25a and the photosensitive drum 21. Further, by setting SF-1 and SF-2 to 180 or less, it is possible to suppress the problem that the toner is scattered on the image and the image quality is lowered.

Further, the toner T has a length (major axis) in the major axis direction as r1, a length (minor axis) in the minor axis direction as r2, and a length (thickness) in the thickness direction as r3. ,
0.5 ≦ r2 / r1 ≦ 1.0
0.7 ≦ r3 / r2 ≦ 1.0
r1 ≧ r2 ≧ r3
The relationship is established.
If the ratio of the major axis to the minor axis (r2 / r1) is less than 0.5, the distance from the true spherical shape is lowered, so that the dot reproducibility and transfer efficiency are lowered and high quality image quality cannot be obtained. If the ratio of thickness to short axis (r3 / r2) is less than 0.7, the shape is close to a flat shape and a high transfer rate cannot be obtained. In particular, when the ratio of the thickness to the short axis (r3 / r2) is 1.0, a rotating body having the long axis as the rotation axis is obtained, and the fluidity of the toner can be improved. Note that r1, r2, and r3 were measured with a scanning electron microscope (SEM) while taking and observing photographs while changing the angle of field of view.

Spherical toners are produced by heat-treating irregularly shaped toners (pulverized toners) whose shapes are distorted by a conventionally used pulverization method, or by suspension polymerization methods or emulsion polymerization aggregation methods. Can be used.
The toner manufacturing method in the present embodiment includes a toner material liquid in which at least a polyester prepolymer having a functional group containing a nitrogen atom, a polyester, a colorant, and a release agent is dispersed in an organic solvent. Among them, a toner is formed by crosslinking or / and extension reaction.

  When such a spherical toner is used, conventionally, transfer efficiency is improved, but a slight gap between the cleaning blade 25a and the photosensitive drum 21 enters the gap and eventually causes a cleaning failure. However, in this embodiment, in order to improve the toner peelability (removability) on the photosensitive drum 21 by applying the lubricant to the surface of the photosensitive drum 21 by the lubricant supply devices 25b and 45 to 47. The occurrence of defective cleaning and filming is suppressed.

In this embodiment, silica fine particles are added to the surface of the base particles of the toner T. The silica fine particles are formed so that the average primary particle size is 50 to 300 nm and the bulk density is 0.3 g / cm ³ or more. As a result, the toner is charged well, the transfer efficiency is improved, abnormal images such as firefly images are also suppressed, and high-quality and stable image quality can be obtained.

The toner T used in the present embodiment has a volume average particle diameter of 3 to 8 μm, and a ratio (Dv / Dn) between the volume average particle diameter (Dv) and the number average particle diameter (Dn). The toner has a small particle size in the range of 1.00 to 1.40 and a narrow particle size distribution. By using a toner having a small particle diameter, the toner can be densely attached to the latent image. Further, by narrowing the particle size distribution, the toner charge amount distribution becomes uniform, a high-quality image with little background fogging can be obtained, and the transfer efficiency can be increased.
In the case of using a toner having a small particle diameter, conventionally, the toner enters the slight gap between the cleaning blade 25a and the photosensitive drum 21, and eventually passes through the gap, resulting in poor cleaning. However, in this embodiment, in order to improve the toner peelability (removability) on the photosensitive drum 21 by applying the lubricant to the surface of the photosensitive drum 21 by the lubricant supply devices 25b and 45 to 47. The occurrence of defective cleaning and filming is suppressed.

  The carrier C used in the present embodiment uses spherical ferrite particles having an average particle diameter of 50 μm as a core material, and a silicone resin in which an aminosilane coupling agent is dispersed as a coating material. Specifically, an aminosilane coupling agent and a silicone resin are dispersed in toluene, and after the dispersion is prepared, the core material is spray-coated in a heated state. Further, after firing and cooling, carrier particles having an average coat resin film thickness of 0.2 μm are prepared.

  Referring to FIG. 2, the cleaning device 25 includes a cleaning blade 25 a that comes into contact with the photosensitive drum 21, a brush-like roller 25 b as a brush-like rotating member around which brush bristles that slide in contact with the photosensitive drum 21 are provided, The solid lubricant 45 is in contact with the roller 25b, the compression spring 46 is configured to urge the solid lubricant 45 toward the brush roller 25b, the scraper 47 is in contact with the brush roller 25b, and the like.

  The cleaning blade 25a is made of a rubber material such as urethane rubber, and is in contact with the surface of the photosensitive drum 21 at a predetermined angle and a predetermined pressure. As a result, deposits such as untransferred toner adhering to the photosensitive drum 21 are mechanically scraped and collected in the cleaning device 25.

  The brush-like roller 25b serving as the brush-like rotating member has brush hairs wound around the outer periphery of the core metal, and the brush hairs are in contact with the surface of the photosensitive drum 21 in the clockwise direction of FIG. Rotate. Thus, the lubricant is supplied from the solid lubricant onto the photosensitive drum 21 via the brush-like roller 25b. Thus, the brush roller 25b, the solid lubricant 45, and the compression spring 46 function as a lubricant supply unit (lubricant supply device).

On the other hand, the brush-like roller 25b also functions as a cleaning brush that scrapes off deposits such as untransferred toner that adhere to the photosensitive drum 21. More specifically, deposits such as untransferred toner adhering to the photosensitive drum 21 are scraped off by the brush-like roller 25 b and then scraped off by the scraper 47 and collected in the cleaning device 25. Here, as the deposits adhered to the photosensitive drum 21, in addition to the untransferred toner, paper dust generated from the recording medium P (paper), discharge products generated on the photosensitive drum 21 during discharge by the charging unit 22. And additives added to the toner.
In this embodiment, the photosensitive drum 21 is moved in the reverse direction (counterclockwise in FIG. 2) at a predetermined timing before the lubricant is supplied onto the photosensitive drum 21 by the lubricant supply units 25b and 45-47. The toner staying at the edge of the cleaning blade 25a is removed.
The configuration and operation of the lubricant supply units 25b and 45 to 47 will be described in more detail later.

The image forming process described above will be described in more detail with reference to FIG.
The developing roller 23a rotates in the direction of the arrow in FIG. The developer G in the developing device 23 is supplied from the toner replenishing portion 32 to the toner replenishing port by the rotation of the first conveying screw 23b and the second conveying screw 23c arranged with the partition member 23e interposed therebetween. It circulates in the longitudinal direction while being agitated and mixed with the toner T replenished through 23f (in the direction perpendicular to the plane of FIG. 2).

  Then, the toner T that is frictionally charged and adsorbed on the carrier C is carried on the developing roller 23 a together with the carrier C. The developer G carried on the developing roller 23a then reaches the position of the doctor blade 23d. The developer G on the developing roller 23a is adjusted to an appropriate amount at the position of the doctor blade 23d, and then reaches a position facing the photosensitive drum 21 (developing area).

  Thereafter, in the development region, the toner T in the developer G adheres to the electrostatic latent image formed on the surface of the photosensitive drum 21 (rotated in the clockwise direction in FIG. 2). Specifically, the toner T is latently exposed by the electric field formed by the potential difference (development potential) between the latent image potential (exposure potential) of the image area irradiated with the laser light L and the development bias applied to the development roller 23a. Adhere to the image.

  Thereafter, most of the toner T adhering to the photosensitive drum 21 in the developing process is transferred onto the intermediate transfer belt 27. The untransferred toner T remaining on the photosensitive drum 21 is collected in the cleaning device 25 by the cleaning blade 25a and the brush-like roller 25b.

  Here, a toner replenishing unit 32 provided in the apparatus main body 1 includes a toner bottle 33 configured to be replaceable, and a toner hopper unit 34 that holds and rotates the toner bottle 33 and replenishes the developing device 23 with new toner T. And is composed of. Also, a new toner T (any one of yellow, magenta, cyan, and black) is accommodated in the toner bottle 33. In addition, a spiral protrusion is formed on the inner peripheral surface of the toner bottle 33.

  The new toner T in the toner bottle 33 is appropriately replenished into the developing device 23 from the toner replenishing port 23f as the toner T (existing toner) in the developing device 23 is consumed. . The toner T in the developing device 23 is consumed indirectly or directly by the reflective photosensor 41 facing the photosensitive drum 21 and the magnetic sensor 40 installed below the second conveying screw 23c of the developing device 23. Detected.

  Here, in the present embodiment, the toner density (TC) is controlled to be within a predetermined range. Specifically, toner replenishment is performed so that the detection results of the magnetic sensor 40 and the reflection type photosensor 41 have an output value corresponding to the above-described toner density range (the ratio of the toner T in the developer G). The toner is supplied from the unit 32 to the developing device 23 through the toner supply port 23f.

Hereinafter, the configuration and operation of the lubricant supply device 25b and 45 to 47 in the present embodiment will be described in detail.
As shown in FIG. 2, the lubricant supply units 25 b and 45 to 47 (lubricant supply device) are installed integrally with the cleaning device 25. The lubricant supply device includes a brush-like roller 25b as a brush-like rotating member around which brush bristles that slidably contact the photosensitive drum 21, a solid lubricant 45 that contacts the brush-like roller 25b, and a solid lubricant 45 in a brush shape. The compression spring 46 is urged toward the roller 25b, and the scraper 47 is in contact with the brush-like roller 25b. In addition to the original cleaning function, the cleaning blade 25a also has a function of thinning the lubricant applied to the photosensitive drum 21 by the brush roller 25b.

The brush-like roller 25b rotates so as to come into contact with the photosensitive drum 21 rotating in the clockwise direction in FIG. 2 in the counter direction (clockwise rotation in FIG. 2). The brush-like roller 25b is arranged so as to be in sliding contact with the solid lubricant 45 and the photosensitive drum 21, and the brush-like member 25b rotates to scrape off the lubricant from the solid lubricant 45 and lubricate it. An agent is applied on the photosensitive drum 21. The rotational drive of the brush-like roller 25b is performed by a drive source that performs the rotational drive of the photosensitive drum 21. That is, the rotational drive of the brush-like roller 25b is performed in conjunction with the rotational drive of the photosensitive drum 21 by a single drive source.
A compression spring 46 is disposed behind the solid lubricant 45 in order to eliminate contact unevenness between the brush-like roller 25b and the solid lubricant 45, and urges the solid lubricant 45 to the brush-like roller 25b. Yes.
In the present embodiment, the rotation direction of the brush roller 25b is the clockwise direction in FIG. 2, but the rotation direction of the brush roller 25b may be the counterclockwise direction in FIG. Further, although the drive source of the brush roller 25b is used as the drive source of the photosensitive drum 21, the drive source of the brush roller 25b and the drive source of the photosensitive drum 21 can be provided separately.

In the present embodiment, the solid lubricant 45 is formed of zinc stearate. Specifically, the solid lubricant 45 is preferably prepared by dissolving a lubricating oil additive mainly composed of zinc stearate, having no side effects due to overcoating and having sufficient lubricity.
Zinc stearate is a typical lamellar crystal powder. 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 is slippery. Therefore, the surface of the photosensitive drum 21 can be made low in friction. That is, the surface of the photosensitive drum 21 can be effectively covered with a small amount of lubricant by the lamellar crystal that uniformly receives the shearing force and covers the surface of the photosensitive drum 21.

  In addition to the zinc stearate, the solid lubricant 45 includes stearic acid groups such as barium stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, calcium stearate and the like. The thing which has can be used. In addition, the same fatty acid group zinc oleate, barium oleate, lead oleate, the same compound as stearic acid, zinc palmitate, barium palmitate, lead palmitate, the following compound similar to stearic acid May be used. In addition, caprylic acid, linolenic acid, corinolenic acid and the like can be used as the fatty acid group. In addition, waxes such as candelilla wax, canrunauba wax, rice wax, wax, coconut oil, beeswax, and lanolin can also be used. These easily become organic solid lubricants and have good compatibility with the toner.

When the solid lubricant 45 is applied to the surface of the photosensitive drum 21 via the brush-like roller 25b, a powdery lubricant is applied to the surface of the photosensitive drum 21, but the lubricity is sufficient in this state. Since it is not exhibited, the cleaning blade 25a functions as a member for uniformizing the lubricant. The cleaning blade 25a forms a film of the lubricant on the photosensitive drum 21, and the lubricant exhibits its lubricity sufficiently.
At this time, the finer the powdery lubricant applied by the brush roller 25b, the thinner the thin film on the photosensitive drum 21 by the cleaning blade 25a.

Here, in the present embodiment, the solid spring 45 is pressed against the brush roller 25b by the compression spring 46 at a pressure of 200 mN or more. As a result, the friction coefficient of the surface of the photosensitive drum 21 becomes 0.4 or less, and a stable cleaning property can be obtained.
Note that when the pressure (pressing force) of the solid lubricant 45 against the brush roller 25b increases, the amount of lubricant that the brush roller 25b scrapes off from the solid lubricant 45 increases, and the surface is applied to the surface of the photosensitive drum 21. The amount also increases. If the pressing force is too large, an excessive amount of lubricant is supplied to the surface of the photosensitive drum 21, and the friction coefficient of the surface of the photosensitive drum 21 is decreased more than necessary, or the consumption of the solid lubricant 45 is accelerated. . Therefore, the pressure of the solid lubricant 45 against the brush-like roller 25b is preferably set to 3000 mN or less.

Note that the Euler belt method is used to measure the friction coefficient of the photosensitive drum 21. In the Euler belt system, medium-quality high-quality paper is used as a belt, and the paper sheet is stretched in the longitudinal direction so that it is stretched in a range of 1/4 of the entire circumference of the photosensitive drum. Then, a load of 0.98 N (100 g) is applied to one end of the belt, a force gauge is installed on the other end, and the force gauge is pulled. Then, the load at the time when the belt moves is read and substituted into the following equation to calculate the friction coefficient.
Friction coefficient μs = 2 / π × 1n (F / 0.98)
In the above equation, μ is a coefficient of static friction and F is a measured value.

  In the present embodiment, the linear velocity ratio of the photosensitive drum 21 to the brush roller 25b ((linear velocity of the photosensitive drum) / (brush-like) at the sliding contact position between the brush roller 25b and the photosensitive drum 21. The linear speed of the roller)) is set in the range of 0.8 to 1.2. As a result, the transfer residual toner on the photosensitive drum 21 can be efficiently collected, and the lubricant can be efficiently supplied to the photosensitive drum 21.

  In the present embodiment, the linear pressure of the cleaning blade 25a that contacts the photosensitive drum 21 is set in the range of 0.1 to 0.5 N / cm. When the linear pressure of the cleaning blade 25a is less than 0.1 N / cm, a cleaning failure occurs, and when the linear pressure of the cleaning blade 25a is greater than 0.5 N / cm, the photosensitive drum 21 is abraded so that the life is shortened. It will be shorter.

Hereinafter, characteristic operations of the lubricant supply units 25b and 45 to 47 in the present embodiment will be described with reference to FIGS.
As described above, the rotational drive of the brush-like roller 25b is performed in conjunction with the rotational drive of the photosensitive drum 21 in a predetermined direction (the direction of the arrow in FIG. 3). Therefore, when forming a toner image on the photosensitive drum 21, the lubricant is supplied to the photosensitive drum 21 by the rotational drive of the brush roller 25b.

Further, in the present embodiment, the brush-like roller 25b (and the photosensitive drum 21) is driven to rotate even during non-image formation (when the toner image is not formed on the photosensitive drum 21). A lubricant is actively supplied onto the photosensitive drum 21. The timing of the lubricant supply operation at the time of non-image formation can be performed every time the apparatus main body 1 is activated, or can be performed every time a predetermined number of sheets (or a predetermined time) are printed. it can. The image area of the printed output image may be accumulated by the storage means, and the lubricant supply operation may be performed every time the accumulated image area reaches a predetermined value. Further, the lubricant supply operation may be performed every time a predetermined number of images with a high image area ratio are printed.
When performing the lubricant supply operation during non-image formation, it is preferable not to charge the photosensitive drum 21 by the charging unit 22. Thereby, damage given to the photosensitive drum 21 and the lubricant applied to the photosensitive drum 21 can be reduced.

  Then, before supplying the lubricant onto the photosensitive drum 21 by the lubricant supply portions 25b and 45 to 47 (before the brush-like roller 25b is driven to rotate), the photosensitive drum 21 is moved in the reverse direction (the arrow in FIG. 4). Direction). Thereby, the toner staying at the edge portion (tip portion) of the cleaning blade 25a can be removed, and the supply failure of the lubricant onto the photosensitive drum 21 can be suppressed.

  Specifically, when an image with a high image area ratio is continuously printed, a large amount of toner T stays at the edge of the cleaning blade 25a as shown in FIG. If the lubricant is immediately supplied onto the photosensitive drum 21 by the lubricant supply portions 25b and 45 to 47 after such a state occurs (if the brush roller 25b is driven to rotate), FIG. As shown in FIG. 7, the lubricant S supplied onto the photosensitive drum 21 is peeled off from the photosensitive drum 21 by the toner T staying at the position of the cleaning blade 25a (by movement in the direction of the broken arrow in FIG. 7). is there.).

  However, in this embodiment, even when the state shown in FIG. 3 is reached, the photosensitive drum 21 is rotationally driven in the reverse direction (in the direction of the arrow in FIG. 4). As a result, as shown in FIG. 4, the toner T staying at the edge of the cleaning blade 25a moves from the contact position of the cleaning blade 25a along with the reverse rotation of the photosensitive drum 21. Thereafter, the toner T removed from the edge portion of the cleaning blade 25a passes through the sliding contact position (opposite position) between the brush-like roller 25b and the photosensitive drum 21, and the brush-like shape is generated when the driving of the photosensitive drum 21 is stopped. It reaches the position on the upstream side of the roller 25b (the position shown in FIG. 5).

That is, as shown in FIG. 5, the lubricant supply part (brush-like roller 25b) is on the opposite side to the cleaning blade 25a (on the upstream side in the forward rotation direction of the photosensitive drum 21). It is arranged.
The driving distance in the reverse direction of the photosensitive drum 21 is defined as Ra, from the contact position between the cleaning blade 25a and the photosensitive drum 21 to the position where the lubricant supply unit (brush roller 25b) and the photosensitive drum 21 face each other. When the distance of Rb is Rb,
Ra ≧ Rb
The relationship is established.
Thus, the toner T removed from the edge portion of the cleaning blade 25a can be reliably moved to the upstream position (the position shown in FIG. 5) of the brush roller 25b.

Thereafter, when the lubricant supply operation is started (when the rotational driving of the brush roller 25b is started), the lubricant S is supplied onto the photosensitive drum 21 as shown in FIG. Then, the lubricant S supplied onto the photosensitive drum 21 passes through the position of the cleaning blade 25a, and then becomes a lubricant layer S ′ that is uniformly thinned on the photosensitive drum 21.
On the other hand, the toner T removed from the edge portion of the cleaning blade 25a is removed from the photosensitive drum 21 by the brush-like roller 25b that also functions as a cleaning brush, and then carried on the brush-like roller 25b and cleaned by the scraper 47. It is collected in the device 25 (the movement in the direction of the broken arrow in FIG. 6).
As described above, in this embodiment, even when the toner T stays at the edge portion of the cleaning blade 25a, the staying toner is surely removed and the lubricant S on the photosensitive drum 21 is removed. Supply failure can be suppressed.

  The inventor of the present application conducted the following experiment using the image forming apparatus according to the present embodiment in order to confirm the effects of the above-described embodiment.

Experiment 1.
In Experiment 1, a change in the coefficient of friction on the surface of the photosensitive drum 21 due to the reverse rotation operation of the photosensitive drum 21 was confirmed before the lubricant supply operation. Specifically, in order to increase the amount of toner input to the cleaning blade 25a, 100 solid black images having an image area ratio of 100% are printed continuously, and the reverse rotation operation of the photosensitive drum 21 is not performed. The coefficient of friction on the photosensitive drum 21 after the lubricant supplying operation was measured. The lubricant supply operation was performed by turning off the charging unit 22 and rotating the photosensitive drum 21 for 5 seconds during non-image formation.

Other conditions are as follows.
Image forming part: Image forming part for black Brush roller: Material PET
Density 30,000 / inch
Brush thickness 10 denier
Brush diameter 12.0mm
Solid lubricant: Material Zinc stearate
Initial weight about 37g (including sheet metal)
Compression spring pressing force 550mN (× 2)
Photoconductor drum diameter: 300 mm
Brush roller / photosensitive drum linear speed ratio: 1.05
Lubricant supply operation: Execution time 5 seconds
Reverse rotation distance Ra 7mm
Printing conditions: Image area ratio 100% (A4 size)
Number of prints 100 (continuous print)

In this experiment, when the friction coefficient on the photosensitive drum 21 after the lubricant supplying operation is 0.4 or less, the determination result is “◯”, and when the friction coefficient exceeds 0.4, the determination result is “x”.
As a result, when the reverse rotation operation of the photosensitive drum 21 was not performed, the friction coefficient on the photosensitive drum 21 was 0.42, and the determination result was x. On the other hand, when the photosensitive drum 21 was reversely rotated, the friction coefficient on the photosensitive drum 21 was 0.30, and the determination result was good. From this result, it is understood that the friction coefficient of the photosensitive drum is sufficiently reduced by performing the reverse rotation operation of the photosensitive drum before the lubricant supply operation.

Experiment 2.
In Experiment 2, the change in the friction coefficient of the surface of the photosensitive drum 21 when the reverse rotation distance Ra of the photosensitive drum 21 was changed was confirmed. In Experiment 2, the reverse rotation distance Ra of the photosensitive drum 21 was set to 5 mm, and other experimental conditions were the same as those in Experiment 1. The distance Rb between the cleaning blade 25a and the brush roller 25b was 5 mm.

  As a result, when the reverse rotation distance Ra of the photosensitive drum 21 was 5 mm, the friction coefficient on the photosensitive drum 21 was 0.38, and the determination result was “good”. On the other hand, when the reverse rotation distance Ra of the photosensitive drum 21 is 7 mm (the condition of Experiment 1), the friction coefficient on the photosensitive drum 21 is 0.30, and the determination result is ○. From this result, it is understood that if the condition of Ra ≧ Rb is satisfied, the lubricant is more efficiently applied onto the photosensitive drum 21 when the reverse rotation distance Ra of the photosensitive drum 21 is longer.

  As described above, according to the present embodiment, the photosensitive drum is supplied at a predetermined timing before the lubricant S is supplied onto the photosensitive drum 21 (image carrier) by the lubricant supplier 25b, 45-47. 21 is driven in the opposite direction, so that the lubricant S can be stably and uniformly supplied onto the photosensitive drum 21 even when a large amount of toner T stays at the edge of the cleaning blade 25a. Thus, it is possible to reliably reduce the deterioration of the cleaning blade 25a and the photosensitive drum 21, the occurrence of cleaning failure and filming.

In the present embodiment, the cleaning device 25 is integrated with the photosensitive drum 21 and the charging unit 22 to form the process cartridge 20 to reduce the size of the image forming unit and improve maintenance workability. .
In addition, the cleaning device 25 can be configured to be replaceable in the apparatus main body 1 as a single unit without being a component of the process cartridge. Even in such a case, the same effect as the present embodiment can be obtained.
In the present embodiment, the present invention is applied to an image forming apparatus equipped with a two-component developing type developing device 23 using a two-component developer. However, a one-component developing type using a one-component developer is used. Of course, the present invention can also be applied to an image forming apparatus equipped with the developing device 23.
Furthermore, in the present embodiment, the present invention is applied to a lubricant supply device that supplies a lubricant to a photosensitive drum as an image carrier. However, the photosensitive belt or intermediate transfer belt as an image carrier is lubricated. Naturally, the present invention can also be applied to a lubricant supply device that supplies a lubricant.

  It should be noted that the present invention is not limited to the present embodiment, and it is obvious that the present embodiment can be modified as appropriate within the scope of the technical idea of the present invention, other than suggested in the present embodiment. is there. In addition, the number, position, shape, and the like of the constituent members are not limited to the present embodiment, and the number, position, shape, and the like suitable for implementing the present invention can be achieved.

1 is an overall configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating an image forming unit in the image forming apparatus of FIG. 1. FIG. 6 is a diagram illustrating a state where toner is retained at an edge portion of a cleaning blade. It is a figure which shows the state which rotationally driven the photosensitive drum in the reverse direction. FIG. 5 is a diagram illustrating a state in which the photosensitive drum is rotationally driven in the reverse direction following FIG. 4. It is a figure which shows the state which started supply of the lubricant on a photoconductor drum. FIG. 6 is a diagram illustrating a state where the lubricant is detached from the photosensitive drum.

Explanation of symbols

1 image forming apparatus body (apparatus body),
20, 20Y, 20M, 20C, 20BK Process cartridge,
21 photosensitive drum (image carrier), 22 charging unit,
23, 23Y, 23M, 23C, 23BK Developing device (developing unit),
25 Cleaning device (cleaning part, lubricant supply part),
25a Cleaning blade,
25b brush-like roller (brush-like rotating member),
45 solid lubricant,
46 compression springs, 47 scrapers,
S lubricant, T toner.

Claims (15)

An image carrier that is driven in a predetermined direction while carrying a toner image;
A lubricant supply unit for supplying a lubricant to the surface of the image carrier;
A cleaning blade that contacts the image carrier and cleans the surface of the image carrier,
An image forming apparatus, wherein the image carrier is driven in a direction opposite to the predetermined direction at a predetermined timing before the lubricant is supplied onto the image carrier by the lubricant supply unit.   The image forming apparatus according to claim 1, wherein the lubricant supply unit is disposed on a side opposite to the cleaning blade. The reverse drive distance of the image carrier is Ra, and the distance from the contact position between the cleaning blade and the image carrier to the position where the lubricant supply unit and the image carrier are opposed is Rb. sometimes,
Ra ≧ Rb
The image forming apparatus according to claim 1, wherein the following relationship is established.   When the toner image is not formed on the image carrier, the image carrier is driven in the reverse direction, and the lubricant is supplied onto the image carrier by the lubricant supply unit. The image forming apparatus according to any one of claims 1 to 3.   The lubricant supply unit includes a brush-like rotating member in which brush bristles that are in sliding contact with the image carrier and a solid lubricant that contacts the brush bristles of the brush-like rotating member, The image forming apparatus according to claim 1, wherein a lubricant is supplied onto the image carrier by rotating a rotating member.   The image forming apparatus according to claim 5, wherein the solid lubricant is pressed against the brush-like rotating member with a pressure of 200 mN or more.   The linear velocity ratio of the image carrier to the brush-like rotary member at a sliding contact position between the brush-like rotary member and the image carrier is set in a range of 0.8 to 1.2. The image forming apparatus according to claim 5 or 6.   The image forming apparatus according to claim 1, wherein a linear pressure of the cleaning blade contacting the image carrier is set in a range of 0.1 to 0.5 N / cm.   9. The image forming apparatus according to claim 1, wherein the toner relating to the toner image is formed so that an average circularity thereof is 0.93 to 1.00.   The toner relating to the toner image is formed so that the shape factor SF-1 is 100 to 180 and the shape factor SF-2 is 100 to 180. An image forming apparatus according to claim 1. The toner related to the toner image has a length in the major axis direction as r1, a length in the minor axis direction as r2, and a length in the thickness direction as r3.
0.5 ≦ r2 / r1 ≦ 1.0
0.7 ≦ r3 / r2 ≦ 1.0
r1 ≧ r2 ≧ r3
The image forming apparatus according to claim 1, wherein the image forming apparatus is formed so as to satisfy the following relationship. In the toner relating to the toner image, silica fine particles are added to the surface of the base particle,
The silica fine particles have an average primary particle size of 50 to 300 nm and are formed so as to have a bulk density of 0.3 g / cm ³ or more. The image forming apparatus described.   The toner relating to the toner image is obtained by crosslinking a toner material solution in which at least a polyester prepolymer having a functional group containing a nitrogen atom, polyester, a colorant, and a release agent is dispersed in an organic solvent in an aqueous medium. The image forming apparatus according to claim 1, wherein the image forming apparatus is formed by an extension reaction.   The image forming apparatus according to claim 1, further comprising a cleaning device in which the cleaning blade and the lubricant supply unit are integrated.   14. The image forming apparatus according to claim 1, further comprising a process cartridge in which the image carrier, the cleaning blade, and the lubricant supply unit are integrated.

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