JP2000206839A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an image forming device in which an image carrier can be highly durably and highly stably used over a long period and by which an excellent image can be obtained over a long period. SOLUTION: The image forming device using the image forming process of an electrophotographic system is provided with a lubricant supplying means 33 supplying lubricant 34 on the image carrier 11, and at least the lubricant supplying means 33 and a part whose life is the shortest out of the lives of consumables used in the image forming process are integrated. For instance, the lubricant supplying means 33 is integrated inside a housing case 36 housing an electrifying roller 32, so that it is integrated as an electrifying and lubricant integrated type unit 12'. Thus, the lubricant supplying means is provided so as to be integrated with an existing part, so that the lubricant supplying means is inexpensively installed with a simple constitution, and the life of the image carrier can be prolonged by reducing the wear of the image carrier by supplying the lubricant, and the image carrier can be highly durably and highly stably used over a long period.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrophotographic image forming process, such as a copying machine, a facsimile, and a printer.

[0002]

2. Description of the Related Art In an image forming apparatus using an electrophotographic image forming process, such as a copying machine, a facsimile, and a printer, latent images such as optical writing and exposure of a document image are placed on an image carrier charged by a charging unit. An electrostatic latent image is formed by an image forming means, and the electrostatic latent image is developed with a developer of a developing means to become a visible image, and then the visible image is transferred to a recording material such as recording paper by a transfer means. Then, the visible image transferred to the recording material is fixed by a fixing unit to form an image.

In such an image forming apparatus, various methods have been tried for reducing the friction coefficient of the photosensitive member surface by supplying a lubricant to the surface or inside of the photosensitive member (for example, Japanese Patent Application Laid-Open No. 56-07423). No.). With respect to the amount of the lubricant applied, if the lubricant is applied excessively, there occurs a problem that the amount of the toner adhered to the background portion increases or the amount of the attached character of the image portion decreases, resulting in background smear and deterioration in image quality. If the amount is too small, the lubricant is soft and easily worn, so it is difficult to maintain the effect of preventing the fine powder in the toner, which causes the filming layer and black spots, from adhering to the photoreceptor. Is a problem.

In order to solve the above-mentioned problems, various image forming apparatuses provided with a mechanism for controlling the amount of lubricant applied have been proposed (for example, Japanese Patent Application Laid-Open No. Hei 7-311531). Further, in an image forming apparatus using an electrophotographic image forming process, a photoreceptor serving as an image carrier and at least one of a charging unit, a developing unit, and a cleaning unit are integrated to be detachable from the image forming apparatus. There have been many proposals relating to cartridges (for example, see Japanese Patent Application Laid-Open No.
No. 0600), and those in which a unit of parts constituting an image forming process and a lubricant are integrated have not been proposed.

[0005]

In recent years, personalization of copiers, facsimile machines, printers, and the like has been progressing, and downsizing and high durability (maintenance free) of an image forming apparatus using an electrophotographic image forming process have been realized. , High stability and low cost are required. In image forming apparatuses, a small-diameter, thin-film organic photoconductor is often used as an image carrier in order to reduce the size and cost. However, with respect to a thin organic photoreceptor, there is a problem in that the surface of the photoreceptor is shaved when used for a long period of time. The details will be described below.

As the photoreceptor used in the electrophotographic system, an organic photoreceptor has been widely used because of its low cost, high degree of freedom in photoreceptor design, and no pollution. . Organic photoconductors include a photoconductive resin represented by polyvinyl carbazole (PVK), PVK-T
Charge transfer complex type typified by NF (2,4,7-trinitrofluorenone), pigment dispersion type typified by phthalocyanine-binder, function-separated type photoconductor using a combination of a charge generating substance and a charge transporting substance And the like, and particularly, a function-separated type photoreceptor has been receiving attention.

The mechanism of the formation of an electrostatic latent image in the function-separated type photoreceptor is as follows. When the photoreceptor is charged and irradiated with light, the photoreceptor passes through a light-transparent charge transport layer and is charged by a charge generating substance in the charge generating layer. The absorbed charge-generating substance, which has absorbed light, generates charge carriers. The charge carriers are injected into the charge transport layer, move through the charge transport layer according to the electric field generated by the charge, and charge the photoreceptor surface. Thus, an electrostatic latent image is formed by adding them together. In such a function-separated type photoreceptor, it is known and useful to use a charge transport material having absorption mainly in the ultraviolet region and a charge generation material having absorption mainly in the visible region. is there.

On the other hand, it is known that the weak points of the organic photoreceptor are poor mechanical and chemical durability and short life. That is, most charge transport substances have been developed as low molecular weight compounds, but since low molecular weight compounds alone do not have film-forming properties, they are usually used by being dispersed and mixed with an inert polymer. However, the charge transport layer composed of a low molecular charge transport material and an inert polymer is generally soft, and in the electrophotographic process, various contact members (contact type charging means (charging roller etc.), developing means such as developing roller etc.) are repeatedly used. The film is likely to be scraped by a mechanical load received from a recording material such as a recording paper or a cleaning means such as a cleaning brush or a cleaning blade.

The present invention has been made in view of the above circumstances, and provides an image forming apparatus that can use an image carrier with high durability and high stability for a long period of time and can obtain a good image for a long period of time. It is intended to be. It is another object of the present invention to provide an image forming apparatus in which a replacement member such as a consumable used in an electrophotographic image forming process can be more easily replaced and the cost can be reduced.

[0010]

In order to achieve the above-mentioned object, the present invention forms an electrostatic latent image on an image carrier charged by a charging means by a latent image forming means, and forms the electrostatic latent image on the image carrier. After developing with a developer of a developing unit to form a visible image, the visible image is transferred to a recording material by a transfer unit, and the visible image transferred to the recording material is fixed by a fixing unit to form an image. In an image forming apparatus using an electrophotographic image forming process,
A lubricant supply unit for supplying a lubricant onto the image carrier, wherein at least the lubricant supply unit and a component having the shortest life among consumables used in the image forming process are integrated. (Claim 1).

Here, the component having the shortest life is, for example, an image carrier, or a component around the image carrier such as a charging unit, a developing unit, and a cleaning unit. As an example, a configuration is conceivable in which the lubricant supply means is integrated into a unit of the charging means (Claim 3). A relatively short-life component such as a charging roller and a lubricant are integrated into the unit. If it is detachably provided in the image forming apparatus main body, the lubricant can be replaced at the same time when the charging roller is replaced. Further, if the lubricant supply means is composed of, for example, a solid lubricant and a pressure member for pressing the solid lubricant against the image carrier to make sliding contact, the lubricant supply means can be simplified. Cost can be reduced.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the structure, operation and operation of the present invention will be described in more detail. In the present invention, in order to achieve the above-mentioned object, in order to achieve the above-mentioned object, abrasion of the thin-film photoreceptor due to friction between a thin-film photoreceptor (for example, an organic photoreceptor) and members around the photoreceptor and a film thickness on the surface Means for reducing scraping were studied. As a means for achieving the above-mentioned object, a method for reducing the surface friction coefficient of the thin-film photoreceptor was adopted. It is for the following reasons. In an electrophotographic image forming process, many members are in contact with the periphery of a photoconductor. Among them, the cleaning blade is said to be the one that contributes the most to the shaving of the photosensitive member surface.

Here, problems in the conventional cleaning process will be described. Deterioration of the photoreceptor is a factor that determines the life of the photoreceptor. If the wear amount of the photoreceptor layer of the photoreceptor is reduced by a certain amount, the electrical characteristics of the photoreceptor change, and a predetermined amount of the wear is reduced. This is because the image forming process cannot be performed. This abrasion occurs in all portions of the image forming process where the photoconductor and other image forming units come into contact with each other. However, the most problematic unit is a cleaning unit provided with a cleaning blade for mechanically removing the toner particles remaining on the photoreceptor. Although there is abrasion by other units, it does not affect the real life.

The abrasion generated in the cleaning section is mainly classified into two forms. One is abrasion due to the shearing force generated on the photosensitive member and the cleaning blade, and the other is rough wear in which the toner acts like a grindstone when the toner is sandwiched between the cleaning blade and the photosensitive member. Factors that determine these abrasions are the structural strength of the photoreceptor,
The contact pressure of the cleaning blade, the composition of the toner particles, the surface friction coefficient of the photoreceptor, and the like are given. Among them, the present inventors are studying a means for reducing the surface friction coefficient of the photoreceptor.

Here, a method of reducing the coefficient of friction of the thin-film photosensitive member will be described. By supplying a lubricant for maintaining the surface characteristics of the photoconductor and various stabilizers for protecting the characteristics of the photoconductor, wear of the photoconductor layer and deterioration of the photoconductor characteristics can be suppressed. A forming device can be obtained. For example, by adding a lubricant to the photoconductor, the friction coefficient between the photoconductor and the cleaning blade can be reduced.

The present invention is characterized in that a lubricant supply means is used to reduce the friction coefficient. Applying a lubricant to the photoreceptor to reduce the coefficient of friction on the photoreceptor surface can prevent unnecessary toner adhesion and provide an image free from background contamination. Body surface is constantly refreshed, photoconductor life is extended,
The life of the image forming apparatus itself is prolonged, the cost can be reduced, and the amount of toner adhering to the non-image area can be reduced, so that the advantages of effective use of toner and resource saving can be achieved.

Here, the Euler belt method which is a method for measuring the coefficient of friction of the photosensitive member surface in the present invention will be described.
The Euler belt method is a method of measuring a coefficient of friction between paper and a photoconductor. FIG. 3 shows an example of a specific measurement method. In FIG. 3, the belt 2 is 30 mm × 250 mm
Medium-thick high-quality paper (# 6200 paper (T-th)), hooks are attached to both ends, and a load (for example, 10
5), a digital force gauge 1 is installed on the other side, a cylindrical photoreceptor 3 is used as a photoreceptor, and the digital force gauge is fixed in a 90 ° direction using a photoreceptor support 4. 1, the value F at the time when the belt 2 started to move was read and substituted into the following equation (1) to calculate the photoconductor surface friction coefficient μ. μ = ln (F / W) / (π / 2) (1) where F: value indicated by digital force gauge W: load (100 g weight in this experiment) π: pi

Generally, when the lubricant is not actually used, the surface friction coefficient μ of the organic photoreceptor (when not used) is 0.5.
After performing an electrophotographic image forming process, the pressure rises to about 0.6 to 0.7, the sliding pressure of the cleaning blade increases, and blade squeal and photoreceptor wear are reduced. The likelihood of being promoted increases. On the other hand, when the surface friction coefficient μ of the photoconductor becomes 0.1 or less,
It can be expected that the wear resistance is improved and the cleaning property is improved. However, if the lubricant adheres unnecessarily on the photoreceptor, it slips too much, causing the developer or toner to slip, resulting in a blurred character edge. In this case, the resolution appears to be improved at first glance, but the sharpness is deteriorated, and the uniformity of the halftone image is reduced, resulting in a rough image. Therefore, it does not mean that the lower the surface friction coefficient μ of the photoreceptor, the better, and the preferable range of the friction coefficient is 0.4 or less, more preferably 0.1.
It is desirable to be in the range of 0.3 to 0.3, and if it is 0.1 or less, the image quality tends to be deteriorated. From these facts, the supply amount of the lubricant is determined by setting the surface friction coefficient μ of the photoconductor to 0.1.
It is desirable to set the amount so that it can be maintained in the range of 1 to 0.3.

Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. Note that a drum-shaped photoconductor is used as a representative example of the image carrier, but the same applies to a photoconductor of another shape, an intermediate transfer belt, and the like. Absent.

First, an example of the configuration and operation of an image forming apparatus using an electrophotographic image forming process according to the present invention will be described. FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention. In the image forming apparatus 10, each unit of a charging unit 12, an optical writing unit 13, a developing unit 14, a transfer unit 19, a charge removing unit 25, and a cleaning unit 26 is provided around a drum-shaped photoconductor 11 as an image carrier. A fixing unit 24 is provided downstream of the transfer unit 19 in the conveyance direction of the recording paper 18.

When the image forming process is executed, the image forming apparatus 10 rotates the drum-shaped photosensitive member 11 serving as an image carrier in a clockwise direction, and charges the photosensitive member 11 to a charging unit (for example, a charging unit 12). An optical writing unit 13 (for example, a laser scanning device that performs optical writing by scanning a laser beam or an optical writing device that uses an LED array or the like) that is a latent image forming unit after being uniformly charged by a charging roller or the like. Irradiates an electrostatic latent image forming light modulated with image data to form an electrostatic latent image on the photoconductor 11.
Then, a developing unit 14 is placed on the photoconductor 11 on which the electrostatic latent image is formed.
Of the developer 1 in the developing unit 17 by the developing roller 16
Then, the toner of No. 5 is adhered and developed to form a visible image. The image forming apparatus 10 further rotates the photoconductor 11 on which the toner is adhered by the developing unit 14 to form a toner image.
The toner image is transferred onto the recording paper 18 transported between the photoconductor 11 and the transfer belt 20. The transfer belt 20 of the transfer unit 19 is wound around conveyance rollers 21a and 21b and rotates in the direction of the arrow in the figure to convey the recording paper 18 to transfer the toner image on the photoconductor 11 to the recording paper 18 and ,
The recording paper 18 to which the toner image has been transferred is conveyed to the fixing unit 24. Then, the recording paper 18 conveyed to the fixing unit 24 is heated and pressed by the fixing roller 22 and the pressure roller 23 to fix the toner image on the recording paper 18 onto the recording paper 18.
The paper is discharged onto a paper discharge tray (not shown).

On the other hand, the image forming apparatus 10 further rotates the photoconductor 11 on which the toner image has been transferred onto the recording paper 18 by the transfer unit 19, removes the charge by the charge removing unit 25, and then removes the cleaning unit 2.
The toner remaining on the surface of the photoreceptor 11 is scraped off by a cleaning blade 6 and the like, and the cleaned photoreceptor 11 is uniformly charged again by the charging unit 12, and then subjected to the next image formation as described above. .

In the present invention, it is assumed that the image forming apparatus has a configuration in which a lubricant is applied to the surface of the photoconductor 11.
Therefore, the image forming apparatus according to the present invention includes a lubricant supply unit (not shown in FIG. 1) for supplying a lubricant to the surface of the photoreceptor 11, and further includes a lubricant supply unit and an image forming process. It is characterized by integrating parts having the shortest life among the consumables used in the above. Here, typical examples of the lubricant supplied to the photoconductor surface include:
Examples include the following, but are not limited thereto. Hereinafter, specific examples of the lubricant will be described.

Solid type lubricants include lead oleate, zinc oleate, copper oleate, zinc stearate, cobalt stearate, iron stearate, copper stearate, zinc palmitate, copper palmitate, zinc linolenate. Metal salts such as fatty acids, talc (talc), polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polytrifluorochloroethylene, dichlorodifluoroethylene, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene- Fluorinated resins such as oxafluoropropylene copolymers and natural waxes such as carnauba wax.

Liquid type lubricants include synthetic oils such as silicone oil and fluorine-based oil, animal oils such as squalane oil, vegetable oils such as rapeseed oil, and mineral oils. Are both valid,
In consideration of long-term stability, it is preferable to use a synthetic oil such as a silicone oil or a fluorine-based oil.

FIG. 4 is a graph showing the time-dependent changes in the friction coefficient μ of the photoconductor surface when the lubricant is supplied to the photoconductor surface and when the lubricant is not supplied to the surface of the photoconductor by the Euler belt method (FIG. 3). The photoreceptor surface friction coefficient μ increases as the time for performing the image forming process elapses.
It is known that it rises rapidly in the early stage as shown in FIG. Further, when the lubricant is supplied, the surface friction coefficient of the photosensitive member can be kept low as long as the supply is continued.

As the lubricant, the above-mentioned liquid, semi-solid, and solid substances are commercially available, and any of them can be used, but solids are best in consideration of easy handling. If powder is used among solids, it is difficult to handle because powder easily scatters in the image forming apparatus. Therefore, a solid lubricant obtained by solidifying powder is the easiest to handle, has good transferability to an image carrier such as a photoconductor, and does not adversely affect image formation.

The life of the lubricant supplied onto an image carrier such as a photoreceptor depends on the conditions such as the material, shape and thickness of the lubricant. The life of components used in the image forming process arranged around the image carrier varies depending on conditions such as the material, structure, shape, and rotational speed. Therefore, in a normal image forming apparatus, the components and the lubricant disposed around the image carrier are selected in accordance with the target product specifications. The present invention proposes an integrated structure in which at least the lubricant and the component having the shortest life among components arranged around the image carrier have the same life. The life of the lubricant can be adjusted relatively easily by changing the above conditions such as shape and material. Further, the smaller the amount of the lubricant combined with the component having the shortest life, the smaller the integrated unit can be made, which is suitable for miniaturization of the device.

As described above, the image carrier such as the photoreceptor is mechanically received from various contact members (charging roller, developing roller, recording material, cleaning brush, cleaning blade, etc.) by repeated use. Since the load is applied, even if the life is extended by supplying the lubricant, the life is not extended forever, and replacement is necessary according to the frequency of use. If the life of the lubricant is shorter than the life of the image carrier, the lubricant cannot be supplied before the image carrier is replaced, and the surface friction coefficient of the image carrier increases, so that the life of the image carrier is shortened. Therefore, unless the lubricant is changed more frequently than the replacement timing of the image carrier, or if the lubricant is not replaced according to the replacement timing of the image carrier, the life of the image carrier is maximized. Can not be used.

According to the intensive studies of the present inventors, since the lubricant supplied to the surface of an image carrier such as a photoreceptor is excellent in transferability to the image carrier, a member such as a thin sheet or plate is used. Have proven to be suitable. However, when a thin sheet-like or plate-like lubricant is used, the sheet is scraped by sliding with the image carrier, and the life is substantially shortened. However, when a thin sheet-like or plate-like lubricant is used, the transferability is good when the lubricant is replaced, so that the lubricant can be efficiently supplied. Further, since the sheet-like or plate-like shape is advantageous in terms of space, the size of the image forming apparatus can be reduced.

As described above, the amount of the lubricant can be changed according to the required life. Of course, if the required amount is large, a place for storing is required, which leads to an increase in the size of the machine. That is, lubricants that can save space and can be supplied in a sufficient amount are desirable, but because they are conflicting requirements, they cannot be satisfied at the same time, or it is very difficult, if at all.

Next, each unit constituting the image forming apparatus according to the present invention, the life thereof, and the replacement time will be described. The component having the shortest life used in the image forming apparatus according to the present invention is, specifically, an image carrier such as the photoconductor 11 in FIG. 1 or a charging unit 12, a developing unit 14, and a transfer unit 1.
Reference numeral 9 denotes a component of each unit such as the cleaning unit 26 and the components around the image carrier. However, since the recording paper 18 passes between the transfer portion and the photoconductor 11, it is not suitable for integrating the lubricant.

As the photoreceptor currently used as an image carrier, there are various types such as an inorganic photoreceptor such as a selenium photoreceptor and the above-mentioned organic photoreceptor. Among them, the organic photoreceptor has advantages such as low cost, high degree of freedom in designing the photoreceptor, and non-pollutability. For this reason, the organic photoreceptor has been widely used. However, since the organic photoreceptor is a thin film, it has a disadvantage that its life is short. If an organic photoconductor having a longer life is manufactured in the future, the life of the image carrier may be equal to or longer than the life of the image forming apparatus. When the life of the image carrier is prolonged, the image carrier is used up to the life of the apparatus, and other parts having a shorter life than the image carrier and the machine are replaced. In the electrophotographic image forming process, it is preferable that the component parts have as long a life as possible from the viewpoint of energy saving and cost reduction. At present, however, there are many parts that do not last until the life of the apparatus, and these parts are replaced by service personnel or users.

As mentioned above, the amount of lubricant can be varied according to the required life. Of course, if the required amount is large, a place for storing is required, which leads to an increase in the size of the machine. In other words, lubricants that can save space and can be supplied in a sufficient amount are desirable, but they are conflicting requirements and cannot be satisfied at the same time, or it is very difficult even if they can be achieved. Therefore, in the present invention, the amount of the lubricant is adjusted and integrated with the shortest-life parts so that they can be replaced at the same time, so that the image forming apparatus can be reduced in space and cost. This also improves user maintenance and makes it easy for ordinary users to replace the battery.

In the past, components constituting the image forming process were replaced independently according to their lifespan. Recently, however, a mechanism called a process cartridge (an image carrier and a unit for charging, developing and cleaning have been integrated). Since the mechanism has been put to practical use, the replacement is performed once and replaced with the component having the shortest life. However, in this configuration, when the process unit is replaced, parts that can still be used are also replaced at the same time, so that there is a problem that resources are wasted and the environment is adversely affected. For example, when the lubricant is integrated in the process cartridge, when the image carrier is replaced, the replacement is performed in spite of the surplus lubricant, and there is a problem that the material is wasted.
It can cause adverse effects on environmental problems.

Therefore, the present invention proposes a unit integrating at least a lubricant supply unit and a component having the shortest life among components used in an electrophotographic image forming process, and an image forming apparatus provided with the unit. are doing. In addition, if there are other parts having the same life, other parts may of course be integrated. The unit integrated with the lubricant supply means is detachably provided in the main body of the image forming apparatus to facilitate replacement. In addition, a mechanism that can be attached and detached from the front of the apparatus is preferable in consideration of maintainability. In consideration of the superiority of handling, if the lubricant supply means is combined with a component having the shortest life to form a unit, and a mechanism is provided with a handle or the like to make the unit easy to hold, the portability is simplified. As an example, a configuration is conceivable in which the lubricant supply means is combined with a charging roller or the like having a relatively short life to form a unit and is detachably provided on the apparatus main body, and a handle or the like is attached to this unit to make it easier to hold. Can be

As a unit around the image carrier, a unit provided with a lubricant supply unit in the cleaning unit has been proposed, but there is no unit in which the charging roller and the lubricant supply unit are integrated in the unit. . In order to extend the life of the image carrier, there is a method of indirectly supplying a lubricant from the charging roller onto the image carrier. In the present invention, the lubricant is directly supplied to the image carrier. And is not necessarily supplied onto the image carrier via the charging roller. That is, in the configuration in which the lubricant is supplied via the charging roller, the charging unit is limited to the charging roller, but if the charging unit and the lubricant supplying unit are integrated into one unit, the charging unit is Alternatively, non-contact type charging means other than the charging roller may be used. Further, in the configuration in which the lubricant is supplied via the charging roller, there is a problem that dirt or the like easily adheres to the charging roller and causes uneven charging. That is, among the members constituting the image forming process, if the charging roller used in contact with the image carrier particularly has uneven charging due to surface dirt or the like, it adversely affects image formation. Therefore, in order to use the charging roller used in contact with the image carrier in a good state for a long period of time, it is better to apply the lubricant directly to the image carrier without passing through the charging roller.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, as a specific embodiment of the present invention, a unit (in which the charging roller and the lubricant supply means which are considered to have a relatively short life in the image forming apparatus shown in FIG. 1) are integrated. Hereinafter, the charging / lubricating unit is shown in FIG.
In the configuration of FIG. 2, the charging unit 12 of FIG. 1 is a charging / lubricating integrated unit 12 ′, and a lubricant supply unit 33 is integrated into a storage case 36 that stores the charging roller 32. The charging roller 32 is fixed to the charging / lubricating integrated unit 12 ′ by a charging roller pressing member 31 formed of a spring or the like.
The photosensitive member 1 serving as an image bearing member is supported by the storage case 36 of FIG.
1 and is brought into contact therewith, and the surface of the photoconductor 11 is uniformly charged. The lubricant supply means 33 is provided with a plate-like solid lubricant 3.
4 and a lubricant pressing member 35. The lubricant 34 is also charged and charged by the lubricant pressing member 35 such as a spring.
The lubricant is supported by the storage case 36 of the lubricant-integrated unit 12 ′ and slidably contacts the photoconductor 11 in a state where the lubricant is pressed by the lubricant pressing member 35 to supply the lubricant.

During operation of the image forming apparatus, when the photoconductor 11 rotates clockwise as indicated by an arrow in the figure, the lubricant 34 is pressed against the photoconductor 11 by the lubricant pressing member 35 and In order to make the sliding contact, the lubricant at the sliding contact portion is scraped and transferred onto the photoconductor 11. Thereafter, the charging roller 32 rotates around the photoconductor 11 to uniformly charge the photoconductor 11. Thereafter, image formation is performed by the image forming process (latent image forming, developing, transferring, and fixing steps) described with reference to FIG.

In the charging / lubricating unit 12 ′ having the structure shown in FIG. 2, the life of the lubricant 34 in the storage case 36 is set to be the same as that of the charging roller 32.
The charging roller 32 is pressed by the pressing member 31 and is used in sliding contact with the photoreceptor 11. However, since the lubricant supply speed is set to match the life of the charging roller 32, the amount of the lubricant supplied is limited by the lubricant pressing member. It is controlled by adjusting the pressing force of 35. In addition, by supplying an appropriate amount of lubricant before charging, a favorable image can be obtained without adversely affecting image formation as compared with the case where lubricant is supplied via a charging roller. Further, since the lubricant supply means 33 is integrated in the case 36 accommodating the existing charging roller 32, the lubricant supply means can be installed with a simple configuration, and the cost can be reduced.

[0041]

As described above, since the image forming apparatus of the present invention is provided with the lubricant supply means for supplying the lubricant onto the image carrier, the wear of the image carrier due to the supply of the lubricant is provided. , The life of the image carrier can be extended, and the image carrier can be used with high durability and high stability for a long period of time. Further, the life of the image carrier can be made substantially the same as or longer than the life of the lubricant, so that the life of the image carrier can be maximized and used, and good image formation can be performed. it can. Also, the lubricant supply means and the parts having the shortest life among the consumables used in the image forming process, for example, the image carrier, or the parts around the image carrier such as the charging means, the developing means, and the cleaning means are integrated. With this, the lubricant supply means can be installed at a low cost with a simple configuration, and the number of parts replacement can be reduced.
Time and cost can be reduced. Further, when exchanging the lubricant with the image carrier or other parts having the shortest life, there is no wasted material, so that the environment is not adversely affected and resources can be saved. Further, the user can exchange the lubricant with the image carrier having reached the end of its life or other parts having the shortest life, thereby improving the maintainability. In this case, for example, the lubricant supply unit is replaced with a unit (storage case) such as a charging unit.
By integrating the unit, the unit can be detached from the image forming apparatus main body and easily replaced.
Further, if the lubricant supply means is composed of, for example, a solid lubricant and a pressing member for pressing the solid lubricant against the image carrier to make sliding contact, the configuration of the lubricant supply means can be simplified and the cost can be reduced. In addition, integration with components used in the image forming process is facilitated.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present invention.

FIG. 2 is a view showing one embodiment of the present invention, and is a schematic cross-sectional view showing a configuration example of a charging / lubricating integrated unit in which a charging roller and a lubricant supply unit are integrated.

FIG. 3 is an explanatory diagram of a method of measuring a photoreceptor surface friction coefficient by the Euler belt method.

FIG. 4 is a diagram showing a change over time of a photoconductor surface friction coefficient depending on whether a lubricant is supplied or not.

[Explanation of symbols]

 1: Digital force gauge 2: Belt 3: Photoconductor 4: Photoconductor mounting table 5: Load 10: Image forming apparatus 11: Photoconductor (image carrier) 12: Charging unit (charging means) 12 ': Charging / lubricant Integrated unit 13: Optical writing unit (latent image forming unit) 14: Developing unit (developing unit) 15: Developer 16: Developing roller 17: Developing unit 18: Recording paper (recording material) 19: Transfer unit (Transfer unit) 20: Transfer belts 21a, 21b: Conveying roller 22: Fixing roller 23: Pressure roller 24: Fixing unit (fixing unit) 25: Static elimination unit 26: Cleaning unit (cleaning unit) 31: Charging roller pressing member 32: Charging Roller (charging means) 33: Lubricant supply means 34: Lubricant 35: Lubricant pressing member 36: Storage case for integrated charging and lubricant unit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor: Adult Kojima 1-3-6 Nakamagome, Ota-ku, Tokyo / Ricoh Co., Ltd. (72) Inventor Hiroshi Nagame 1-3-6 Nakamagome, Ota-ku, Tokyo Ricoh Co., Ltd. (72) Inventor Yota Sakon 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (reference) 2H027 HB04 HB13 HB14 HB16 2H034 AA07 2H071 BA03 BA13 BA32 DA06 DA08 DA13 DA15

Claims (4)

[Claims] An electrostatic latent image is formed by a latent image forming means on an image carrier charged by a charging means, and the electrostatic latent image is developed into a visible image by developing with a developer of a developing means. An image forming apparatus using an electrophotographic image forming process, wherein the visible image is transferred to a recording material by a transfer unit, and the visible image transferred to the recording material is fixed by a fixing unit to form an image. In the above, there is provided a lubricant supply means for supplying a lubricant onto the image carrier, and at least the lubricant supply means and a part having the shortest life among consumables used in the image forming process are integrated. An image forming apparatus comprising: 2. The image forming apparatus according to claim 1, wherein the component having the shortest life is an image carrier or a component around the image carrier such as a charging unit, a developing unit, and a cleaning unit. Characteristic image forming apparatus. 3. An image forming apparatus according to claim 1, wherein said lubricant supply means is integrated within a unit of a charging means. 4. An image forming apparatus according to claim 1, wherein said lubricant supply means comprises a solid lubricant and a pressure member which presses said solid lubricant against an image bearing member to make sliding contact. An image forming apparatus comprising: