JPH11212398A - Image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably rotate an image carrier and to suppress abrasion of a photoreceptor by forming an image by an image forming device equipped wit a lubricant coating device for coating the image carrier with lubricant in a uniform thin film state by a brush-like rotator arranged to abut on the image carrier. SOLUTION: The image is formed by the image forming device equipped with the lubricant coating device for coating the image carrier with the lubricant in the uniform thin film state by the brush-like rotator arranged to abut on the image carrier, and a coating amount controller for controlling the coating amount of the lubricant. The coating member 201a of the lubricant coating device is a lubricant impregnated member which is impregnated with the lubricant and constituted to abut on a coating brush 201c, which is the brush-like rotator. A case, which holds the member 201a, is equipped with a movable device 201b capable of moving back and forth, and a driving device 203 actuating a solenoid and a controller 204 controlling the device 203 are connected to the device 201b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method in an image forming apparatus such as a facsimile, a printer, and an electrophotographic copying machine. Specifically, a lubricant is applied to an image carrier (photoconductor) by an image forming apparatus using a blade cleaning method.
The present invention relates to an image forming method in which an image is formed while being applied to a substrate and controlled.

[0002]

2. Description of the Related Art Generally, in an image forming apparatus such as a printer, a copying machine, and a facsimile, an image is formed by a series of processes including charging, exposure, development, transfer, and cleaning. In these image forming methods or apparatuses, for the purpose of improving the cleaning property, making the image uniform, improving the transfer efficiency, improving the wear resistance of the image carrier (photoconductor), and the like, the following improvement measures, namely, There are several disclosed examples of a method and an apparatus for forming an image by applying or adding a lubricant to an image carrier (photoreceptor).

(1) Japanese Patent Application Laid-Open No. 8-202226 An image forming apparatus in which a device for applying a lubricant (such as zinc stearate) to an image carrier via a brush while controlling the amount of application thereof is installed in a cleaning unit. (2) Japanese Patent Application Laid-Open No. 8-305233 An image forming apparatus having a control device for detecting a toner image formed on an image carrier and applying a lubricant according to the reference value. Zinc stearate is used as a lubricant. (3) JP-A-6-342236 An image forming apparatus provided with an apparatus for applying a lubricant (such as zinc stearate) to an image carrier via a charging roller. (4) JP-A-54-1630 and JP-A-54-1632.
Nos. 54-143142, 64-35448, 6
Japanese Unexamined Patent Publication No. 3-244039, etc. A photoconductor in which a silicone-based or fluorine-based lubricant is contained or applied to the outermost layer of the photosensitive layer, or a layer containing the lubricant is provided.

Although the main objects of these disclosed examples are slightly different from each other, effects of stabilizing the image quality, prolonging the life of the photoreceptor, improving the cleaning property, preventing filming, etc. by utilizing the action of the lubricant. It is aimed at.

[0005] Regarding the disclosure example (1), by applying a brush once applied to a photoreceptor, uniform coating properties are improved, and this is a preferable method for uniforming an image. When zinc stearate with excellent lubricity is applied, it also has excellent wear resistance. However, zinc stearate is difficult to remove once it has adhered to the photoreceptor, and although it has a long-lasting effect, it often involves corona products (the main cause of image deletion) generated during the charging process when applied in large quantities. It will be easier. Further, when the zinc stearate layer is further formed, the scraping effect is greatly reduced, and there is a risk that local image quality is reduced. Therefore, an accurate coating control function for increasing the SN ratio of the sensor and making the sensor extremely thin is required.

The disclosed example (2) is a method of applying a lubricant to an image carrier while shaving the lubricant (here, zinc stearate) with a cleaning brush constituting a cleaning device. The present invention relates to an apparatus that detects a toner image on a carrier and constantly performs uniform coating so that image quality deterioration (contamination of the photoconductor by toner due to filming or the like) does not occur. Toner filming is likely to occur when the coefficient of friction on the photoreceptor is reduced, and the main causes are corona products and resins, dyes or pigments constituting the toner. Therefore, the coefficient of friction of the photoreceptor surface is reduced, the cleaning performance is increased, and
It can be suppressed by weakening the adhesive force. It is a good method to control the amount of application by judging the image on the photoconductor. Zinc stearate is easy to adhere, has excellent lubricating properties and excellent properties, such as the effect of being applied once applied.
As described above, because of its good adhesion, if it adheres to the contact surface (corner) between the cleaning blade and the photoreceptor, it is difficult to easily remove components such as corona products and toner on the photoreceptor surface due to slippage. is there. Therefore, a problem arises that even if a problem occurs, it cannot be solved immediately. That is, zinc stearate is easy to entrain the corona product, and once entrained, the corona product accumulates and remains on the photoreceptor until the zinc stearate is removed,
There is a problem that problems such as image deletion are prolonged. Therefore, it is necessary to control the coating so as to be extremely thin so that no problem occurs.

[0007] Regarding the disclosure example (3), the lubricant is applied once to a charging roller having a linear speed different from the rotation speed of the photoconductor, and the lubricant is applied again to the photoconductor so that the photoconductor has a lubricating effect. Things. This method eliminates coating unevenness by changing the linear velocity and performs uniform coating. However, since a waxy solid such as zinc stearate is used as in (1), When used in a charging system, if there is any non-uniformity of coating, unevenness in electrical resistance is likely to occur, the charging uniformity of the photoconductor is lost, and image defects (for example, black spots, blurring, etc.) occur. There is an easy risk. However, it involves the same risk of image deterioration as in (1), but since it is limited to the charging roller, the generation of corona products is extremely small as compared with the corona discharge method, and the risk of blurred images is small.

In the disclosure example (4), a silicone-based or fluorine-based oil or powder is contained or dispersed in the surface layer of the organic photoreceptor to provide lubricity. This method has a great merit that the photoreceptor has lubricity and does not require a system change of the apparatus main body. However, when oil is added, the amount is limited to an extremely small amount, and the added oil naturally migrates to the surface layer and is lost during development, transfer, and cleaning, thus maintaining the lubrication effect. However, there is a problem that the effect remains at an early stage, and the effect is lost in about 100 copies. On the other hand, the photoreceptor provided with a layer in which a fluorine-based powder is dispersed near the outermost surface of the photosensitive layer has persistence,
Due to the electric resistance and dispersibility of the powder to be dispersed, the electrophotographic characteristics of the photoreceptor are liable to be impaired, and there is a problem that a rise in the residual potential and, when used over a long period, the generation of minute black spots and blurring occur. In addition, since the effect of suppressing the adhesion of the corona product is not perfect, the increase in the friction coefficient cannot be completely suppressed, and a powder such as polyvinylidene fluoride (made by Kureha Chemical Co., Ltd.) is also used in terms of lubricity. It is also necessary.

[0009]

As described above, although the above disclosed example has advantages, it still has problems and has not yet been solved to solve these problems. Therefore, in view of these problems, an object of the present invention is to provide a lubricating member that does not cause serious defects in an image by using an image carrier (in this case, an organic photoconductor).
By applying means and control method to apply uniformly to the photoreceptor, the photoreceptor is given a stable rotation, suppresses the abrasion of the photoreceptor, improves the cleaning performance, and improves the transfer efficiency of the toner image. An object of the present invention is to provide an image forming method for stably supplying a good image having a high S / N ratio for a long period of time.

[0010]

The above object can be achieved by performing the following image forming method. That is, according to the present invention, (1) an image forming method of forming an electrostatic latent image by charging and image-exposing an image carrier, developing the image with a developer, and transferring and cleaning to form an image. A lubricant applying device for applying a lubricant composed of lubricating oil or lubricating grease on the image carrier in a uniform thin film by a brush-like rotating body arranged so as to abut on the image carrier; and applying the lubricant. An image forming method in which an image is formed by an image forming apparatus having a coating amount control device for controlling the amount, (2) the lubricant is a silicone-based or fluorine-based lubricating oil or lubricating grease. The image forming method according to the above (1), wherein
(3) The viscosity of the lubricant is 50 CS or more at 25 ° C. and 10,000 or more.
The image forming method according to the above (1) or (2), wherein the lubricating oil is CS or less, and (4) the friction coefficient on the image carrier after applying a lubricant and forming a thin film is 0.4. (1) The image forming method according to any one of (1) to (3), wherein (5) a lubricant is uniformly applied immediately before mounting or in advance so that the friction coefficient is 0.4 or less. The image forming method according to any one of (1) to (3) above, wherein the image carrier is attached to the image forming apparatus to perform image formation.

In the image forming method according to the first aspect, the image carrier (here, the organic photoreceptor) has various problems in image formation from the beginning or over time. That is, the blade squeals and the photoreceptor lock at the initial stage, the wear of the photosensitive layer, the poor transfer of the toner image, the non-uniformity of the image, and the like occur with time. This occurs because the coefficient of friction of the photoconductor increases from the beginning or over time. Means for solving or suppressing these problems can be improved by lowering the friction coefficient of the photoconductor. The means includes a lubricant applying means using a brush-like rotating body capable of uniformly applying a lubricant composed of lubricating oil or lubricating grease to the image carrier in a thin film, and constantly grasping the surface state of the photoreceptor. However, this can be achieved by using means for controlling the application of the lubricant according to the surface condition.

The object of the present invention is to provide a method for forming an image by using a silicone-based or fluorine-based oil or grease which has a high lubricating effect, does not decompose or solidify, and has good long-term stability as a lubricant. Problem can be improved.

In the image forming method according to the third aspect, the lubricating effect depends on the viscosity (or molecular weight) of the lubricating oil, and the operability is good when the viscosity is 50 CS or more and 10,000 CS or less at 25 ° C. And a target friction coefficient is obtained.

According to a fourth aspect of the present invention, there is provided an image forming method, wherein a blade squeal which occurs when the photosensitive member is brought into contact with a blade during rotation of the photosensitive member is suppressed, abrasion of the photosensitive layer is improved, transfer efficiency of the toner image is improved,
The friction coefficient of the photoreceptor must be 0.4 or less in order to obtain and maintain an image having a good S / N ratio without background background contamination, improved cleaning properties, and the like.

According to a fifth aspect of the present invention, there is provided the image forming method, wherein the charge transport layer of the organic photoreceptor has a polycarbonate resin ΔA,
When manufacturing a photoreceptor using｝ such as C or Z type (manufactured by Teijin Chemicals Ltd.), a few drops of a leveling agent such as silicone oil may be added to obtain uniformity of the photosensitive layer. Thereby, the friction coefficient of the photosensitive layer is reduced to about 0.5.
In this state, when mounted on a photoreceptor unit, etc., there is no problem if the blade pressure is set low,
Generally, it is set higher in consideration of a decrease in cleaning performance when the photosensitive layer is worn, and in this case, since the frictional resistance between the blade and the photosensitive member is large, the photosensitive member does not rotate, or Even if it rotates, high-frequency friction noise is generated due to friction with the blade, which may make it unusable. In order to prevent this, a fine lubricating powder such as polyvinylidene fluoride or strontium titanate is further applied to a blade or a photoreceptor. However, depending on the surface in contact with the cleaning blade, that is, the material type (for example, the charge transport layer material) constituting the outermost layer of the photoconductor, the lock may not be released. As a means for solving this problem, a lubricant (lubricating oil or lubricating grease) having a friction coefficient of 0.4 or less may be applied to the photosensitive member immediately before mounting or in advance. That is, this operation guarantees smooth rotation of the photoconductor.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to the drawings. The copying process will be described with reference to the schematic diagram of this embodiment (FIG. 1). A charging device (here, a roll-shaped contact charging device is shown) on the image carrier (photoconductor) 101
102 charges (±) 400 to 1400V.
The charging polarity differs depending on the type of material constituting the photoconductor. In recent years, there are organic photoconductors (OPCs), which are the mainstream of photoconductors and are applied photoconductors according to the present invention, which operate with negative charge and those which operate with positive charge.

2 (a) to 2 (d) show a photosensitive member configuration showing a typical embodiment used in the present invention. FIG.
(A) is a single layer type of a photosensitive layer 5 in which an undercoat layer 2 is formed on a conductive support 1 and a charge transporting material and a charge generating material are integrated thereon, and (b) is a conductive support. 1. A function-separated type photoconductor in which a charge generation layer 3 and then a charge transport layer 4 are formed on 1; (c) an undercoat layer 2 is formed between the conductive support 1 and the charge generation layer 3; A function-separated type photoreceptor having a charge transport layer 4 formed thereon, and FIG.
Is a photoconductor on which a protective layer 6 is formed. In the case of positive charging, the configuration of FIG. 2A is used.
Photoconductors having the configurations shown in FIGS. 2B to 2D are often used.
The main reason for forming the charge transport layer 4 on the upper surface is to increase the durability. When the charge generation layer 3 is formed on the uppermost surface, the protection layer 6 is required in most cases. Further, in order to further extend the wear resistance of the function-separated type photoconductor as shown in FIG.
The protective layer 6 may be formed.

As the binder resin of the charge transporting material, various polycarbonate resins are often used, and the donor can increase the hole mobility. The polycarbonate resin is used because it has good properties such as good weather resistance, no polarity dependency, excellent wear resistance, and transparency.

After the positive or negative charge is applied (charged) to the photoconductor, a latent image is formed by the image exposure system 103. In the case of an analog copier, the original image illuminated by the exposure lamp is projected by a mirror on the photoreceptor in the form of an inverted image in the form of a reverse image, and is formed.
The original image read by the (charge coupled device) is 630 to 78
It is converted to a digital signal of a 0 nm LD or LED and formed on a photoconductor. Therefore, analog and digital wavelength ranges are different. By image formation, charge separation is performed in the photosensitive layer, and a latent image is formed on the photosensitive member. The photoreceptor 101 on which a latent image has been formed in accordance with the document is developed by a developer in a developing device 104, and the original image is visualized (toner image).

Next, the toner image on the photosensitive member is transferred to the transfer device 10.
5 is transferred to the copy paper 109 and the fixing device 108
And sent to hard copy. On the other hand, after the transfer of the photoconductor 101, the toner image is cleaned and cleaned by a cleaning device 106 (consisting of a cleaning brush 106b and a cleaning blade 106a). Since the latent image (original image) on which the toner image has been formed is somewhat retained on the photoreceptor after cleaning, a static eliminator (generally, red light is used) 107 for erasing and uniforming the latent image 107 , The preparation for the next latent image formation is completed, and a series of copying processes is completed.

Next, a problem in the copying process, which is an object of the present invention, will be described. As the charging method, at present, a corona charging method of charging a photosensitive member by performing a silent discharge, and moving and charging a conductive member having a resistance of about 10 ² to 10 ¹² Ω · cm while contacting the photosensitive member. The contact charging method has been put to practical use. Any one of the above-described charging methods is used for the photoreceptor. Ozone and nitrogen oxides (= NOx) that degrade the characteristics of the photoreceptor as by-products other than the charge during charging
Corona products such as are generated. There is a big difference between the amount of this generation between plus and minus.
Compared to positive charging, the amount of corona products generated is overwhelmingly large.For example, when looking at the amount of ozone generated by the corona discharge method,
Positive charging is about 1/10 to 1/100 of negative charging. When the amount of generation is compared by the charging method, the contact charging method is much smaller than the corona discharge method, and the amount of generated ozone is 1/100 to 1/200 of the corona discharge method.
And the amount of nitrogen oxide is about 1/50 to 1/100.

As described above, the amount of corona products such as ozone and nitrogen oxides differs depending on the charging device, but these corona products are extremely harmful substances for forming an image. That is, among the corona products, ozone
Although designated as an environmentally dangerous gas species, its chemical properties include bleaching action and strong oxidizing action, so it can break the intermolecular bonds of the components of the photoreceptor, transport the photoreceptor, Decreases photosensitive function. Therefore, at the time of production, a monophenol compound such as 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole,
Bisphenol compounds such as 2,2'-methylene-bis- (4-ethyl-6-t-butylphenol);
Antioxidants such as polymeric phenolic compounds such as 3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, hydroquinones, and organic phosphorus compounds Alternatively, an oxidation inhibitor or a plasticizer is often added in an amount of 1 to 20% by weight. As a result, the penetration of ozone into the layer can be suppressed, but the surface layer of the photosensitive layer is constantly exposed to ozone, so that the function of the antioxidant decreases, the surface resistance decreases, and moisture in the atmosphere is easily adsorbed. And the image quality is degraded.

On the other hand, in the case of nitrogen oxides, it combines with moisture in the atmosphere to form nitric acid, which similarly lowers the electrical resistance of the photosensitive layer. In the case of nitric acid, however, the function of an antioxidant hardly works.
It penetrates into the photosensitive layer to cause a decrease in the resistance of the photosensitive layer, resulting in a decrease in image quality such as image deletion.

As described above, the influence of the corona product is very large, but the generation of these gas species is extremely small in the contact charging method. Therefore, it is desirable to use a contact charging method which is advantageous for image formation.

The problems when the corona product adheres to the photoreceptor are summarized as follows. Image quality degradation such as resolution degradation and sharpness degradation occurs. Further, due to photoreceptor contamination, the coefficient of friction (increase of frictional resistance) increases, local transfer failure of an image, a decrease in cleaning performance, blade squeal (increases the sliding pressure of the blade, the photoreceptor vibrates, and When the noise is severe, the blade is entangled and the photoconductor is locked, and problems such as accelerated wear of the photosensitive layer occur. Therefore, in order to maintain a high-quality image for a long period of time, means for avoiding these problems is required.

Next, as means for suppressing and improving the above problems, means (control) for reducing the coefficient of friction of the photosensitive member and maintaining the state will be described. Generation of corona products and adhesion (adsorption) of corona products to photoconductors
Although it cannot be avoided, the above problem can be suppressed or avoided if the surface is formed with a low friction coefficient such that it can be easily removed even if it adheres. That is, this is achieved by applying a lubricant to the surface of the photoreceptor. The lubricant has physical properties (having sufficient lubricity, an electrical resistance of at least 10 ¹⁴ Ω · cm, a refractive index close to 1.0, a chemical stability and no deterioration, etc.) which does not inhibit the electrophotographic properties, It needs to be applied in a uniform thin layer on the surface of the photoreceptor.

Solid lubricants having the function of a lubricant include lead oleate, zinc oleate, copper oleate, zinc stearate, cobalt stearate, iron stearate, copper stearate, and palmitic acid. A polymer containing metal fatty acids such as zinc, copper palmitate, zinc linolenate, talc (talc), and fluorine. Polytetrafluoroethylene (trade name: Teflon), polychlorotrifluoroethylene, tetrafluoroethylene, and ethylene With polyvinylidene fluoride, copolymer of tetrafluoroethylene and oxafluoropropylene, polychlorotrifluoroethylene, polytrifluorochloroethylene, dichlorodifluoroethylene,
Fluorinated resins such as polytrifluoroethylene, and fibrous fibers made of fluororesin include fibrous materials such as polyfluorocarbon and polytetrafluoroethylene. Examples of the powder type include polyvinylidene fluoride powder, the above-mentioned fluororesin powder, and talc (talc) powder.

The liquid type includes animal oils such as silicone oil, fluorine synthetic oil, whale oil and squalane oil, vegetable oils such as rapeseed oil, safflower oil, sesame oil, camellia oil and bran oil, paraffinic and naphthenic minerals. There are oil, petroleum, ester, polyether, hydrocarbon, silicone, and fluorine synthetic oils. However, considering long-term stability, it is desirable to use synthetic oils such as silicone oils and fluorine-based oils. Silicone oils include methylphenyl silicone oil, dimethyl silicone oil, and silicone polyether copolymer oils, and modified silicone oils include fluorine-modified, epoxy-modified, alcohol-modified, alkyl-modified, and amino-modified silicone oils. It is an oil that shows good lubrication, although there are some differences in its effects. Fluorocarbon oils include fluorocarbon oils,
And perfluoroether oils.

In the present invention, a grease-based lubricant can also be used. It is considered that the lubricating grease has a thickener (thickening agent) dispersed as a fibrous mill and bonded at many points to form a three-dimensional network structure as a whole, in which lubricating oil is retained. As lubricating grease, calcium soap grease, sodium soap grease as a thickener,
In addition to soap-based greases such as lithium soap grease, calcium complex grease, and barium complex grease, non-soap-based greases such as benton, fine silica, and copper phthalocyanine allyl urea are available. These base oils include those using diester oil, silicone oil, fluorocarbon oil, Yukon oil and the like. In view of long-term stability, image quality, etc., the present invention considers fluorine grease, silicone grease , Silicone-fluorine-based silicone, and fluorine-based synthetic lubricating grease are preferred. In addition, any other materials that do not deteriorate the photoreceptor and do not solidify can be used, and are not limited to these types. The consistency is JISK-
Those having a consistency number of 00 to 4 specified in 2200 (1995) can be used.

The means for reducing the friction coefficient of the photoreceptor is to apply the above-described oil system as thinly as possible. If the oil is applied thickly, the photoreceptor becomes dirty due to the adhesion of toner, and the latent image during development is reduced. It affects the resolution during formation and development. Further, the cleaning blade becomes too slippery, the cleaning performance is reduced, and image quality such as image deletion is reduced.

Next, means for applying and maintaining a lubricant will be described. The application unit makes the application member contact the photoconductor, applies the lubricant to the application member continuously or intermittently, and performs the application by rotating at a high speed (100 to 1000 rpm). It is desirable that the coating film is a uniform ultra-thin film. As the application member, a foam material such as a sponge, or a roll having a nonwoven fabric of ultrafine fibers in the outermost layer can be used. However, when used for a long period of time, a material that easily retains a lubricant is not preferred. A preferred material has a brush structure, and the length of the ear is about 2 to 10 mm, and the diameter of the ear of the brush is about 20 to 100 μm. Rabbit hair or tan hair can be used as the material, but it is expensive, and if wet, the ears may stick together, causing uneven coating,
Considering the long-term stability and long-term stability, it is not so preferable, and it is more preferable to use a chemical fiber such as nylon, polypropylene, or polyester alone or a durable one mixed with the above-mentioned fiber or carbon fiber.

As a coating member, it is possible to use a brush in a cleaning device. However, there is a possibility that the toner sticks, and if possible, it is desirable to provide a dedicated coating device. The application method is to apply the lubricant continuously or intermittently while rotating the application member brush, and indirectly apply it to the photoreceptor. Only the brush rotates to evenly spread the lubricant. As a guide, it is only necessary to reproduce a sufficiently glossy surface without distortion. If there is a residue, the coating film will be distorted and the blade will not mechanically be involved, but the frictional resistance will not reach the desired coefficient of friction, and not only the cleaning blade but also the photoconductor will be contaminated with toner, It causes soiling and a decrease in sharpness. This is particularly important when using grease.

The lubricating oil has a viscosity of about 0.1 CS to a viscosity of several million CS, but it is necessary to select a lubricating oil in a suitable range that can be used. If the viscosity is too low, the coefficient of friction cannot be reduced, and it tends to volatilize, the adhesion to the photoreceptor is weak, and it is easily scraped off with a blade, and the effect of suppressing blade squeal is insufficient. On the other hand, if the viscosity is high, the effect of lowering the friction coefficient increases, but if it is too high, application (workability) becomes difficult, and it takes time to form a thin film, which is not practical.

The viscosity of the lubricant changes depending on the temperature. The higher the temperature, the better the fluidity, and the lower the temperature, the worse the fluidity. Therefore, a control temperature is required. Here, the temperature is set to 25 ° C., and the applicable viscosity range at an environmental temperature of 25 ° C. is 5
0 CS or more and 10000 CS or less, preferably 100 to 100 CS
3000 CS. More preferably, 100 to 100
0CS. Even with the same viscosity, the lubricating properties tend to be better in the fluorine type than in the silicone oil type. In molecular weight,
A range of about 700 to 40000 can be used.

The coating amount is set to such an extent that uniform coating can be performed in a short time. If the viscosity is high, it takes time to apply uniformly, so rather than applying many lubricants at once, it is desirable to apply the lubricant intermittently to the application brush and apply it to the photoconductor several times. However, when the brush is used to a certain extent, the lubricant is adapted to the brush, so that the brush can be applied at an interval such that the brush is applied to the photoreceptor half a circle. The smaller the diameter of the photoreceptor, the easier the application.

The thickness of the lubricating layer after coating film formation is 1 μm or less,
It is expected to be several tens to several hundred angstroms (ー ム). The state in which the uniformity is impaired as described above can be seen from distortion of reflected light, which occurs due to excessive attachment of the lubricant and affects image forming properties.

The maintenance of the coefficient of friction is performed by a detection sensor for grasping the surface condition of the photosensitive member. The reason why it is necessary to maintain the friction coefficient is as follows. The surface of the photoreceptor is contaminated by corona products and developer components
The friction coefficient increases due to minute scratches or the like caused by the blade, brush, or developer, and the various problems described above occur. A lubricant is applied to improve or suppress this, but if the lubricant is excessively adhered, a new problem occurs.
For example, there are contamination by unnecessary toner, image disturbance, poor cleaning of contaminants due to sliding of the cleaning blade, and accompanying image deletion. The attached lubricant adheres to the cleaning blade, developer, copy paper, etc., and is gradually removed.However, if the amount of the attached lubricant is large, slippage occurs, and the removal efficiency is reduced. If it occurs, it will not be possible to solve it. Therefore, a means for controlling the application of the lubricant is required.

The surface condition of the photoreceptor surface is measured by a pressure sensor (strain gauge sensor, piezoelectric sensor, etc.) for detecting the frictional resistance of the photoreceptor as pressure or weight. Pressure sensors are distorted when pressure or weight is applied to the sensor. The distortion is converted into a voltage or a current and taken out as an output. The above-mentioned pressure sensor is manufactured by an element maker such as Kyowa Dengyo, TEAC, Okura, and Chino, and is available. There are various sensors with various sensing widths, 10 grf / cm ^{2 to} 500 k
gf / cm ² , which can be selected according to the situation. In the present invention, it may be in the range of 30 to 1000 grf / cm ² . For example, in the case of a piezoelectric type sensor manufactured by Kyowa Dengyo, PGM-G, PSL-A, PD-A and the like can be used. For strain gauge type, P3000
Series ones are available. As a specific example,
Process such that rubber-like elasticity, poor slipperiness, and damage to the photoreceptor that do not easily damage the photoreceptor can be attached to the sensor receiving side (tip),
The contact is placed so that it contacts the photoreceptor surface.

As the surface contamination of the photosensitive member advances or the lubricating oil is depleted, the frictional resistance increases, so that the pressure applied to the sensor (contact) increases and the output voltage increases. That is, the friction coefficient increases. This signal (voltage) is taken into the control device, the drive device is set to operate when the input signal reaches a certain voltage range, and the drive device works to apply the lubricant to the application device.

The controlled coefficient of friction after application of the lubricant is 0.1.
4 or less, and preferably in the range of 0.05 to 0.3. However, it should be noted that even when the friction coefficient is within the above range, for example, when the friction coefficient at a low level of about 0.08 is maintained for a long time, the phenomenon that the developer slips due to slipperiness. May occur, and an image may appear as if the edge portion of the image is blurred. However, in the initial state where the photoconductor is not contaminated, the occurrence of the problem is small. On the other hand, when the low friction coefficient is long, the scraping of the corona product by the blade becomes insufficient, and the corona product accumulates on the photoreceptor, which may cause a phenomenon called image deletion.

Accordingly, a good result can be obtained in that the photosensitive layer cannot be scraped, but if the function of the blade does not work, the blade will not remove the corona product attached to the photosensitive member, and the above-described problem occurs. That is, the blade must maintain a certain effect of shaving the photosensitive layer. For these reasons, a more desirable range of the coefficient of friction is 0.1 to 0.3. Incidentally, the coefficient of friction of the organic photoreceptor when the lubricant is not applied is between 0.5 and 0.6, and 0.6 to 0.7 after using the copying process.
And the rubbing pressure of the cleaning blade is increased to promote blade squeal and abrasion of the photoreceptor.

The coefficient of friction used in the present invention was measured by the following measuring method. Image carrier for measurement (drum shape)
Is fixed on it, and a belt having a width of 30 mm and a length of 29
Produce 0mm high quality paper and put 100g on one end of the high quality paper
lower the weight of r and attach a digital force gauge to the other end to measure the weight.
Pull the gauge slowly, read the weight at the moment the belt starts to move, and calculate the coefficient of static friction by the following equation (Euler-belt method).

[0043]

Μ = 2 / π × 1n (F / W) where μ: coefficient of static friction, F: reading load, W: weight of weight, π: pi The measurement method (Euler belt Related article about the method) is disclosed in Japanese Unexamined Patent Publication No. 9-16691.
No. 9 also shows this.

The components of the lubricating layer coated on the surface of the image carrier are analyzed by infrared spectroscopy (IR), X-ray photoelectron spectroscopy, chromatography and the like.

[0045]

Next, the present invention will be described in more detail with reference to examples. The lubricant application device is provided between the cleaning device and the static elimination device in the copying process, together with the cleaning device or separately. Here, a method in which the cleaning brush is not used as an application device, that is, a method in which a dedicated lubricant application device is installed will be described. If the influence on the image due to toner contamination can be avoided, a method of installing the cleaning device in the cleaning device is also possible. FIGS. 3 (a) and 3 (b) are schematic diagrams of the lubricant application unit. FIGS. 4 (a) and 4 (b) and FIGS. 5 (a) and 5 (b) show schematic diagrams of examples in which a lubricant application device is incorporated at the upper end of the cleaning device.

The application member 201a is a lubricant impregnated member impregnated with a lubricant, and has a structure in contact with the application brush 201c. A foam material such as sponge can be used for the lubricant impregnated member 201a. In the lubricant impregnated member 201a having a coating layer 201d as shown in FIG. 3B, in addition to the foam material, glass wool, felt, cotton, A member having a performance of retaining a lubricant such as carbon fiber and activated carbon fiber is used. The application brush 201c is a brush-like rotating body. The reason for using the application brush 201c is to apply the brush to the brush and to uniformly spread and polish the photoreceptor surface after the application. That is, since the liquid film is thickened and has no uniformity only by the application, the toner easily adheres and the image is easily disturbed.

Therefore, in order to obtain a normal image, a uniform thin film is required, and unnecessary lubricant must be removed (preferably, a method of extending the lubricant with a small amount is preferable. Insufficient eyes give better overall results.) For this purpose, a brush-like rotating body is used. The material of the brush is not particularly limited, but it is preferable that the brush ears are closely planted in order to form a film without unevenness, and that the material of the brush is durable and does not damage the photoreceptor. System) is effective.

After the lubricant is applied to the rotating application member intermittently or continuously over about 1 to 3 turns, the lubricant impregnated member 201a is separated from the application brush 201c and the application member 201c is It rotates to spread the lubricant adhering to the photoreceptor surface evenly and to make it thinner. Therefore, the photoconductor 10
It is preferable that the amount of the lubricant applied to 1 be as small as possible. This coating operation is preferably performed before or after the end of copying, but can be performed even during copying, for example, when several hundred copies are made.

The lubricant impregnated member 201a may be provided with a hole 201e for injecting lubricating oil into the casing. The case holding the lubricant impregnated member 201a has a movable device 201b (mainly a spring 2) that can move back and forth.
012b and a solenoid 2011b), and a movable device 201b is connected to a drive device 203 for operating the solenoid and a control device 204 for controlling the drive device.

The control device 204 is connected to a line from a detection sensor 202 for judging the surface condition (friction coefficient or friction resistance) of the photosensitive member. A chip that comes into contact with the photoconductor is attached to the detection sensor 202, and the pressure received by the chip is transmitted to the detection sensor 202, and the output voltage from the detection sensor 202 changes according to the pressure. The chip of the detection sensor 202 is flexible, and a rubber material (polyurethane rubber or the like) having a frictional resistance with the photoconductor is suitable. Control device 20
4, the output signal is received and transmitted to the driving device 203, but a certain reference voltage is set in the control device 204. If the reference voltage is equal to or lower than the reference voltage, there is no output to the driving device 203 and a certain reference voltage is output. When it exceeds, the drive device 203 functions to operate. The reference voltage is set at a voltage reflecting the friction coefficient of the photoconductor.

As described above, the coefficient of friction is set at 0.4 or less, preferably in the range of 0.05 to 0.3, and more preferably in the range of 0.1 to 0.3. Is desirable. However, even if the operation is performed for about several tens of sheets or more between 0.3 and 0.4, there is almost no effect on the image. For example, if the level of 0.08 is maintained for several tens of sheets, Since a problem arises, it is desirable to set so as not to be smaller than 0.1. Even if it temporarily deviates from this range (about 10 copies), there is almost no effect on the image. As the reference voltage, the coefficient of friction is 0.25 to
What is necessary is just to set in the range of 0.35. In normal use,
It is good if the value around 0.2 is maintained.

As the detection sensor 202, a sensor such as a pressure sensor for measuring pressure or weight is used.
Pressure sensors include strain gauge sensors, piezoelectric sensors, etc. When pressure or weight is applied to the sensor,
Causes distortion. The distortion is converted into a voltage or a current and taken out as an output. The pressure sensor is manufactured by a manufacturer such as Kyowa Denki Co., Ltd. or TEAC Co., and is available. Kyowa Electric's piezoelectric sensor uses P
There are model numbers such as GM-G, PSL-A, and PD-A, and the sensitivity is at least about 10 grf.
It is selected from the range of 1000 grf / cm ² according to the situation. In the strain gauge type, a P3000 series or the like can be used as a model.

The drive unit 203 is set so that the drive unit operates when the signal from the detection sensor 202 is larger than the reference voltage, and does not operate when the signal is lower. The reference voltage is set based on the required friction coefficient of the photoconductor.
What is necessary is just to set so that it may not rise above. As an example of the setting condition, the reference voltage may be set so that the driving device operates in the range of the friction coefficient in the range of 0.32 to 0.38.

FIG. 4B shows another example in which the fur brush is removed from the cleaning device, and the cleaning device can be reduced in size as much as the fur brush is removed, which is advantageous in terms of space.
If the transfer efficiency is high and the cleaning performance is sufficient, the fur brush is not necessarily required. FIG.
(A) is still another example, in which a blade 201d is attached to the static eliminator of the application member 201a, and the detection sensor 202 is installed on the static eliminator side. The blade 201d is provided to promote uniform application of the lubricant, and a width of 3 to 5 mm is sufficient. FIG. 5B shows an example in which the detection sensor 202 is returned to the original position.

FIG. 6 shows the operation timings of the sensor output, the control device, and the drive device. The reference voltage is as described above. FIG. 7 shows the relationship between the viscosity of the lubricating oil and the coefficient of friction. The photoreceptor sample is an example of measuring the friction coefficient of silicone oil and fluorine oil having different product numbers and viscosities on an organic photoreceptor of φ30 mm having the configuration shown in FIG. 2B, and the friction coefficient decreases as the viscosity increases. . From this figure, the viscosity of the lubricant (at 25 ° C.) at which a friction coefficient of 0.4 is obtained is 10 CS
However, it is preferably about 50 CS or more, and more preferably 100 CS or more, because the dispersion due to the application amount becomes large.
The viscosity may be at least about that.

Examples 1 to 9 A photoreceptor was produced by the following method as a constitution of a photoreceptor for confirming the effects. φ100
mm aluminum drum with the following composition for the undercoat layer coating solution, the charge generation layer coating solution, the charge transport layer coating solution,
By coating and drying, an undercoat layer having a thickness of 3.5 μm was obtained.
A 2 μm charge generation layer and a 25 μm charge transport layer were each formed to prepare an electrophotographic photosensitive member.

[Coating liquid for undercoat layer] Alkyd resin 6 parts (Beccosol 1307-60-EL, manufactured by Dainippon Ink and Chemicals, Inc.) Melamine resin 4 parts (Super Beckamine G-821-60, Dainippon Ink and Chemicals, Inc.) (Manufactured by Industry Co., Ltd.) Titanium oxide 40 parts Methyl ethyl ketone 200 parts

[Coating solution for charge generation layer] 2.5 parts of trisazo pigment having the following structure

Embedded image Polyvinyl butyral (UCL: XYHL) 0.5 parts Cyclohexanone 200 parts Methyl ethyl ketone 80 parts

[Coating solution for charge transport layer] Bisphenol A type polycarbonate 10 parts (manufactured by Teijin Limited: Panlite K1300) Low molecular charge transport material having the following structure 10 parts

Embedded image Methylene chloride 100 parts Methylphenyl silicone oil (50CS) Several drops

An experimental electrophotographic copying machine (roller contact charging system) modified to attach a lubricating device to the upper end of the cleaning device was prepared. The conceptual diagram is as shown in FIG. The outer diameter of the rotating brush of the application member is φ
The ear is 20 mm in length and made of polyester fiber, and is wound spirally around an axis. The length of the ear is 4 mm, and the diameter of the ear is about 30 to 40 μm. The coating amount range is 305m which can cover almost the photosensitive layer
m. The rotation speed of the brush-like rotating body (coating member) is 1
It was set to 80 rpm.

The lubricant is silicone oil, 10CS ｛S
H200 (Toray Dow Corning)｝, 300CS
{KF96 (Shin-Etsu Chemical Co., Ltd.)}, 1000CS @ SH2
00 (manufactured by Dow Corning Toray), 3000CS
｛KF50 (Shin-Etsu Chemical Co., Ltd.)｝ 10000CS｝ SH
200 (manufactured by Dow Corning Toray), 20000C
S {KF96 (manufactured by Shin-Etsu Chemical Co., Ltd.)} (Examples 1 to 6 in order), fluorosilicone 100CS @ FLS50
No. 7 (manufactured by Asahi Kasei Corporation) 1 type (Example 7), silicone grease SH111 (manufactured by Toray Silicone Co., Ltd.) 1 type (Example 8), and fluorine grease IEL / V (manufactured by NOK Kluber) 1 Seeds (Example 9) were prepared.

A PGM-G type sensor manufactured by Kyowa Dengyo Co., Ltd. was used as a sensor for detecting the surface condition of the photoreceptor, and was processed so that the contact pressure could be varied. The mounting position was the position shown in FIG. The control device for applying the lubricant was set so that the lubricant was not applied too much, and the on / off condition was set so that the friction coefficient, which was confirmed in an experiment in advance, was operated between 0.27 and 0.3. In order to confirm the effect, the charging potential was set to about -850 V and the image area potential was set to about -130 V.

Evaluation was carried out in an environment of 24 to 25 ° C./65% RH, 2,000 sheets / day, A-3 size copy, timely measurement of friction coefficient, and after completion of each condition, images (resolution, image Bokeh) confirmation and measurement of the thickness of the photosensitive layer (abrasion). The number of evaluation sheets was 40,000 sheets (operated for about 20 hours). At the start of the experiment, a powder of polyvinylidene fluoride (manufactured by Kureha Chemical Co., Ltd.) was applied to the tip of the cleaning blade, and it was confirmed that the photosensitive member could be rotated smoothly.

Examples 10 and 11 About 100 CS of squalane oil (animal oil, product number unknown, manufactured by Tomomisha) and about 200 CS of vegetable oil (product number unknown, manufactured by Nisshinsha) were prepared as lubricants. 1-9
The same experiment was performed. These are Examples 10 and 11.

Comparative Example 1 The same apparatus as in Examples 1 to 9, except that the lubricant application brush was removed, and the same photosensitive member and evaluation were carried out. This is referred to as Comparative Example 1 of Examples 1 to 11.

COMPARATIVE EXAMPLE 2 A malt plain (urethane) having high oil resistance and high tensile strength was prepared by punching a lubricant into 300 CS {KF96 (manufactured by Shin-Etsu Chemical Co., Ltd.)} lubricating oil instead of rotating the brush. The effect was confirmed by using a foam (manufactured by Inoac Co., Ltd.) as a coating member (outer dimension φ20 mm). This is referred to as Comparative Example 2 of Examples 1 to 11.

Examples 1 to 11 and Comparative Examples 1 and 2
Table 1 shows the characteristic results of Examples 1, 2, 5, 8,
FIG. 8 shows changes in the coefficient of friction for Comparative Examples 1 and 2. When the lubricant was applied, it was clearly confirmed that the friction coefficient was lower than that in Comparative Example 1 where the lubricant was not applied. However, if the viscosity is as low as 10 CS, it is considered that the result was easily removed and the result of poor persistence of the effect was reflected. As a result, the effect of the lubricant is poor, and the film shaving increases. On the other hand, as the viscosity increases, problems tend to occur in the smoothness after application, and at a high viscosity of 10,000 CS, unlike gel-like grease, the smoothness of the coating film in a short time is inferior, and image deterioration easily occurs. . Further, when the application member was replaced with urethane foam, the result was that the image was easily deteriorated because the uniformity of the coating film was not good. Regarding transferability, a problem occurred in Comparative Example 1 and Examples 10 and 11. When animal and vegetable oils were used as the lubricant, a lubricating effect was clearly obtained, but the resolution was degraded, which was considered to be a decrease in electric resistance, after about 30,000 copies were made. From these facts, it was confirmed that the properties were improved by applying the lubricant. As shown in Table 1, the application effect of the silicone oil-based, fluorine oil-based lubricant and brush rotating body was good.

[0068]

[Table 1]

Examples 12 to 16 Average coefficient of friction when copying 10 to 1000 sheets was 0.52
(0.53-0.48), 0.43 (0.36-0.4)
5), 0.33 (0.32-0.38), 0.22
(0.14-0.17), 0.18 (0.06-0.1
5) Five types of lubricating oils (SH200, KF
96) was selected, and the effect was similarly confirmed using the experimental machines used in Examples 1 to 9 and equivalent photoconductors. These are referred to as Examples 12 to 16 in order. Table 2 shows the results. In addition, before the cleaning, powder of polyvinylidene fluoride (manufactured by Kureha Chemical Co., Ltd.) was applied to the tip of the cleaning blade, and it was confirmed that the rotation of the photoconductor could be performed smoothly.

Even if the friction coefficient of the lubricating oil is high, there is almost no effect on the image, but the abrasion of the photosensitive layer increases. It is apparent from the comparison with Comparative Example 1 that the amount of wear is surely reduced by applying the lubricating oil.
If it is about (0.53 to 0.48), the abrasion of the photosensitive layer will be large, and if 200,000 copies are made, the scraping will be about 3 μm on average (expected).

[0071]

[Table 2]

Examples 17 to 20 The friction coefficient after coating on a photoreceptor and making it uniform was 0.5 to
0.1 lubricating oil. All are silicone oils SH200 (manufactured by Dow Corning Toray) or K
50CS, 300C from F96 (Shin-Etsu Chemical Co., Ltd.)
S, 1000CS and 3000CS were selected, and the rotation of the photoconductor after being applied to the photoconductor in an extremely thin layer was 1
~ 500 sheets were confirmed. The apparatus used was the same experimental machine and the same photoreceptor as in Examples 1 to 9. The type of photoreceptor used here is [Type A]. The lubricating oil is made uniform by first applying it to the entire surface of the photoreceptor with Heize gauze (manufactured by Asahi Kasei Corporation), wiping off excess lubricating oil, and then applying a thin and uniform spread with artificial leather Exaine (manufactured by Toray Industries, Inc.). In this confirmation, the application brush was not operated, and the photosensitive member and the cleaning blade were sufficiently cleaned with ethyl alcohol.
These are referred to as Examples 17 to 20 in order.

Examples 21 to 24 Coefficient of friction after application to photoreceptor and homogenization was 0.5 to 0.5.
0.1 lubricating oil. All are silicone oils SH200 (manufactured by Dow Corning Toray) or K
50CS, 300C from F96 (Shin-Etsu Chemical Co., Ltd.)
S, 1000CS and 3000CS were selected, and the rotation of the photoconductor after being applied to the photoconductor in an extremely thin layer was 1
~ 500 sheets were confirmed. In addition, the resolution of the images before and after and the coefficient of friction were also measured. Apparatuses of Examples 1 to 9
The same experimental machine as in Example 1 was used, and the photoreceptor used for confirmation was a photoreceptor using a polymer donor having the following constitution in the charge transport layer. The type of photoreceptor used here is [Type B].
The lubricating oil is made uniform by first applying it to the entire surface of the photoreceptor with Heize gauze (made by Asahi Kasei Corporation), then wiping off the excess lubricating oil.
Spread thin and even with artificial leather Exaine (made by Toray Industries). In this confirmation, the application brush was not operated, and the photosensitive member and the cleaning blade were sufficiently cleaned with ethyl alcohol. These will be referred to as Examples 21 to 24 in order.

A coating liquid for the undercoat layer, a coating liquid for the charge generation layer, and a coating liquid for the charge transport layer having the following compositions were sequentially applied to an aluminum drum having a diameter of 100 mm and dried to obtain 3.5.
An electrophotographic photosensitive member was prepared by forming an undercoat layer of μm, a charge generation layer of 0.2 μm, and a charge transport layer of 25 μm, respectively.

[Coating liquid for undercoat layer] Alkyd resin (Beccosol 1307-60-EL; 6 parts, manufactured by Dainippon Ink and Chemicals, Inc.) Melamine resin (Super Beckamine G-821-60; 4 parts, Dainippon Ink and Chemicals (Manufactured by Industry Co., Ltd.) Titanium oxide 40 parts Methyl ethyl ketone 200 parts

[Coating Solution for Charge Generating Layer] 2.5 parts of trisazo pigment having the following structure

Embedded image Polyvinyl butyral (UCL: XYHL) 0.5 parts Cyclohexanone 200 parts Methyl ethyl ketone 80 parts

[Coating Liquid for Charge Transport Layer] Polymer charge transport material having the following structure: 10 parts

Embedded image Methylene chloride 100 parts Methylphenyl silicone oil (50CS) Several drops

Table 3 shows the results.

Comparative Examples 3 and 4 Using the above [Type A] and [Type B] photoreceptors, in operation, the application brush was not operated, and the cleaning blade was thoroughly cleaned with ethyl alcohol. A powder of vinylidene chloride (produced by Kureha Chemical Co., Ltd.) was sufficiently applied, and the effect was confirmed as in Example 1. These will be referred to as Comparative Examples 3 and 4 in order as Comparative Examples.

Table 3 summarizes the results.

[0081]

[Table 3]

As is apparent from the above results, the rotation coefficient of the photoreceptor is affected by the friction coefficient, and the lower the friction coefficient, the smoother the rotation. If the coefficient of friction is high, the photoconductor is locked, or blade squeal occurs even if the lock is not performed. Whether or not the photoreceptor rotates smoothly depends on the material type of the outermost layer of the photoreceptor, but the problem can be solved by setting an appropriate friction coefficient. More preferably, the coefficient of friction is at least 0.4 or less.

[0083]

As described above, according to the image forming method of the present invention, the brush-like rotating body is lubricated with the lubricant made of oil or grease in order to reduce the friction coefficient of the image carrier (photoreceptor). A lubricant application amount control device is installed in the lubricant application device so as to be able to always maintain an appropriate friction coefficient, and these are always operated to form an image. A detection sensor (pressure sensor) that determines the surface condition of the
And several are arranged to transmit the magnitude of the sliding state (friction resistance) to the control device. In carrying out this method, if it is determined that the coefficient of friction is high, the drive unit is operated and a lubricant is applied to appropriately adjust the coefficient of friction of the photoconductor surface. If the coefficient of friction of the photoreceptor decreases due to the application of the lubricant, the signal from the sensor decreases, and if the control device determines that the voltage is equal to or lower than the reference voltage, the operation of the drive device is stopped and the lubrication is stopped. The application of the agent is stopped. Therefore, according to this method, by repeating the above operation, the amount of decrease in the thickness of the photosensitive layer is suppressed, the blade squeal is eliminated, and an image with good resolution can be maintained for a long time.

According to the image forming method of the present invention, since a silicone-based or fluorine-based lubricating oil or grease is used as the lubricating oil, a good image can be maintained for a long time according to the present method. .

According to the image forming method of the present invention, a (low to high molecular weight) lubricating oil having a viscosity of 50 to 10,000 CS at 25 ° C. is used as a lubricant.
The operability is good, the rotation of the photoconductor is good, and a good image can be maintained for a long time.

According to the image forming method of the present invention, since the coefficient of friction on the image carrier after forming a thin film by applying a lubricating oil is set to 0.4 or less, according to the present method, the abrasion resistance of the photosensitive layer is improved. The transferability of the toner image, the cleaning property, and the like are improved, the blade squeak and the like do not occur, and a good image can be stably maintained for a long time.

According to the image forming method of the present invention, an image carrier is attached to an image forming apparatus immediately before mounting or beforehand with a uniform application of a lubricating oil so that the coefficient of friction is 0.4 or less. Even in the case of a combination of an organic photoreceptor having extremely high frictional resistance and a cleaning blade, the photoreceptor is not locked, the blade does not squeal, and it is possible to provide a better image than at the beginning.
At the initial stage, there is no adhesion of the corona product to the photoreceptor, so that there is no problem even if the friction coefficient of 0.1 or less is continued for 10 or 20 copies.

According to the method of the present invention, by performing the above operation, the rotation of the photosensitive member is not suppressed, and the friction coefficient of the image carrier (photosensitive member) is lower than in the prior art. Level, the photoreceptor is reduced in wear, the transfer efficiency of the toner image is increased, and the deterioration of the image is suppressed, so that a good image can be maintained for a long time.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a copying process according to an embodiment.

FIGS. 2A to 2D are diagrams showing examples of a layer configuration of a photoreceptor used in the present embodiment.

FIGS. 3A and 3B are explanatory diagrams of a mechanism of a lubricant application section.

FIGS. 4A and 4B are schematic diagrams of an apparatus for applying a lubricant to a photoconductor.

FIGS. 5A and 5B are schematic views of another type of apparatus for applying a lubricant to a photoreceptor.

FIG. 6 is an explanatory diagram showing timing for applying a lubricant.

FIG. 7 is a diagram showing the relationship between the viscosity of a lubricating oil and the coefficient of friction.

FIG. 8 is a diagram showing a transition of a friction coefficient depending on the number of copies.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 conductive support 2 undercoat layer 3 charge generation layer 4 charge transport layer 5 photosensitive layer 6 protective layer 101 image carrier (photoreceptor) 102 contact charging device 103 image exposure system 104 developing device 105 transfer device 106 cleaning device 106a Cleaning blade 106b Cleaning brush 107 Static eliminator (lamp) 108 Fixing device 109 Copy paper 201 Lubricant applying device 202 Detection sensor 201a Lubricant impregnating member 201b Moving device 2011b Solenoid 2012b Spring 201c Coating brush (rotating brush) 201d Coating layer 201e Lubrication Injection hole 203 Drive device 204 Control device

Continued on the front page (72) Inventor Iwa ▲ saki ▼ Yukiko 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Akiyo Nakajima 1-3-6 Nakamagome, Ota-ku, Tokyo No. Ricoh Co., Ltd. (72) Inventor Hiroyuki Fushimi 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd.

Claims (5)

[Claims] 1. An image forming method comprising: forming an electrostatic latent image by charging and image-exposing an image carrier, developing the image with a developer, and performing image formation through a transfer and cleaning process. A lubricant application device for applying a lubricant composed of grease on the image carrier in a uniform thin film by a brush-like rotating body arranged so as to contact the image carrier, and an application amount for controlling the application amount of the lubricant An image forming method, wherein an image is formed by an image forming apparatus including a control device. 2. The image forming method according to claim 1, wherein the lubricant is a silicone-based or fluorine-based lubricant or lubricant grease. 3. The lubricant has a viscosity of at least 50 CS at 25 ° C.
The image forming method according to claim 1, wherein the lubricating oil is 0000 CS or less. 4. The image forming method according to claim 1, wherein a coefficient of friction on the image carrier after applying a lubricant and forming a thin film is 0.4 or less. 5. The image forming apparatus according to claim 1, wherein the image carrier is mounted on an image forming apparatus immediately before mounting or beforehand with a uniform application of a lubricant so that the friction coefficient is 0.4 or less. The image forming method according to any one of the above.