JP2001343861A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of obtaining an excellent image from the initial stage of outputting by preventing the consumption of lubricant from temporarily lowering in the initial stage in the case of exchanging a process cartridge for the new one. SOLUTION: An image carrier 1, lubricant coating means 100 and 101 and a toner checking member 15A are integrated and constituted as the process cartridge which can be attached to/detached from a device main body. Then, the image forming device is provided with a substance supply means 6 for supplying substance capable of achieving absorbing force to the lubricant to the surface of the image carrier. Then, the lubricant coating means and the substance supply means are controlled so that the surface of the image carrier may be coated with the lubricant and the substance may be supplied to the surface of the image carrier by the time image forming operation is started after exchanging the process cartridge for the new one.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a printer and a facsimile, and more particularly, to an image carrier and a toner image forming a toner image on the surface of the image carrier. Forming means, a transfer means for transferring the toner image formed on the surface to a transfer-receiving body, a blocking member for blocking or closing the toner at the time of image formation by approaching or in contact with the surface of the image carrier; A process cartridge including a lubricant application unit for applying a lubricant, wherein at least the image carrier, the lubricant application unit, and the damming member are integrated and detachably mountable to the apparatus main body. And an image forming apparatus.

[0002]

[Prior art]

Conventionally, as this type of image forming apparatus, for example, an image forming apparatus which transfers a toner image formed on the surface of a photoreceptor as an image carrier to a transfer receiving body is known. Further, after the toner image formed on the surface of the photoreceptor is primarily transferred to an intermediate transfer body as an image carrier, the primary transfer image on the surface of the intermediate transfer body is secondarily transferred to a transfer material as a transfer object. An apparatus using an intermediate transfer method for obtaining a final image is also known.
In particular, since the intermediate transfer method is advantageous in terms of miniaturization and less restrictions on the type of transfer material onto which the toner image is finally transferred in recent years, the intermediate transfer method is particularly advantageous for each color toner image in a color image forming apparatus. Is adopted as a superposition transfer method.

In this type of image forming apparatus, local transfer omissions occurring in the primary transfer process and the secondary transfer process cause
An abnormal image called a so-called insect-eating image may occur. This bug-like image tends to occur in a color image forming apparatus having a large total amount of adhered toner. This is because, for example, due to the contact pressure between the developing roller as a toner carrier constituting the toner image forming means and the surface of the image carrier, there is mechanical non-coulomb force between the surface and the toner. Strong adhesion, filming phenomenon in which toner adheres to the surface of the image carrier in the form of a film in the process of repeatedly executing the image forming process, and strong adhesion between the surface and the toner. Is also conceivable.

In order to reduce the adhesive force between the surface of the image carrier and the toner, it has been conventionally proposed to apply a powdery lubricant such as zinc stearate to the surface of the image carrier. Has already been put to practical use on market machines. For example, a lubricant applying means for applying a lubricant to the surface of the image carrier, and a thinning means for thinning the lubricant applied to the surface, which are disposed in contact with the surface via the lubricant as the thinning means There is known an image forming apparatus provided with a blade-shaped lubricant thinning member.

In an image forming apparatus provided with the above-mentioned lubricant applying means and the above-mentioned lubricant thinning member, a cleaning member as a damming member for damping toner at the time of image formation by approaching or contacting the surface of an image carrier. Is also known which is also used as a lubricant thinning member. In such an image forming apparatus, for example, a powdery lubricant is thinned by a blade-like cleaning member (damming member) and residual toner remaining on the surface of the image carrier after transfer is damped by the member. Stop and remove.

On the other hand, heretofore, there has conventionally been used an image bearing member, a cleaning member as the damming member, and a lubricant applying means, which use a process cartridge detachably mountable to an apparatus body. Are known.

[0008]

By the way, the thinner lubricant applied to the surface of the image carrier is gradually peeled off from the surface in the image forming step and consumed.
Specifically, when the toner image formed on the surface of the image carrier is transferred to the transfer member, the toner image is absorbed by the toner, transferred to the transfer member together with the toner and consumed, and the residual toner after transfer is removed. At the time of cleaning, there are a type that is absorbed by the residual toner and is removed and consumed together with the toner, and a type that is transferred to the roller side and consumed when contacting the developing roller. Since the lubricant is consumed as described above, it is necessary to set the lubricant application conditions within a range in which the supply and consumption of the lubricant can be balanced.

However, when the process cartridge is replaced with a new one, an abnormal image such as white streaks on the black portion of the image or an abnormal image such as black streaks on the white portion of the image, contrary to the abnormal image in the form of white streaks. It has been found that images may occur. The present inventors have conducted intensive research to find out the cause, and found that in the initial image forming process after replacing the process cartridge with a new one, the amount of the lubricant consumed when cleaning the residual toner is reduced. However, it has been found that the cause is that the amount of the lubricant consumed when cleaning is performed after the image forming process is repeated for a certain amount or more after the replacement is less than a certain amount. That is, after the replacement, after the image forming process is repeated for a certain amount or more, the toner temporarily blocked and retained by the cleaning member adsorbs the lubricant,
Lubricant is consumed. On the other hand, in the initial image forming process after replacing the process cartridge with a new one, the consumption of the lubricant is reduced because the toner blocked by the cleaning member does not exist or is small. Would. As a result, the balance between supply and consumption of the lubricant is lost.

If the balance between the supply and consumption of the lubricant is lost, the lubricant thinning member may not be able to make the lubricant thinner. When the lubricant adhered to the surface of the image carrier without being thinned comes into contact with the toner carrier, the lubricant sometimes adheres to the thin layer toner carried on the surface of the toner carrier. When the lubricant adheres to the thin layer toner on the surface of the toner carrier, triboelectric charging between the toner (hereinafter referred to as “new toner”) newly supplied to the surface of the toner carrier and the thin layer toner, or a new toner The toner is thinned by contact with the toner carrier. For example, a frictional charge between a blade-shaped toner thinning member or the like is inhibited, and a toner image is not sufficiently formed on the surface of the image carrier. May occur. As a result, an abnormal image in which white stripes occur in the black portion of the image occurs. Further, when the lubricant adheres to the thin toner on the surface of the toner carrier, the lubricant adheres to the toner thinning member, thereby causing a thinning failure of the toner. Contrary to the white streak-shaped abnormal image, an abnormal image such as a black streak occurring in a white portion of the image may occur.

In order to control the amount of lubricant attached when the process cartridge is replaced with a new one, it is conceivable to set the initial amount of lubricant applied after replacement to be small. Specifically, for example, a brush roller is used as a lubricant applying means, and the lubricant attached to the brush roller is applied to the surface by rotating the brush roller while making contact with the surface of the image carrier. In such a case, the brush roller may be separated from the surface of the image carrier for a predetermined time. However, the method of separating the brush rollers is not preferable from the viewpoint of space saving and cost reduction since it is necessary to provide a brush roller contact / separation mechanism.

The present invention has been made in view of the above problems, and an object of the present invention is to prevent an initial temporary decrease in consumption of lubricant when a process cartridge is replaced with a new one. Accordingly, it is an object of the present invention to provide an image forming apparatus capable of obtaining a good image from the beginning of output.

[0013]

In order to achieve the above object, the present invention is directed to an image bearing member, a toner image forming means for forming a toner image on the surface of the image bearing member, and a toner image forming means on the surface. Transfer means for transferring the formed toner image to a transfer-receiving member, a damming member for damping toner at the time of image formation by approaching or in contact with the surface of the image carrier, and a lubricant application for applying a lubricant to the surface And an image forming apparatus, wherein at least the image carrier, the lubricant applying means, and the damming member are integrated and configured as a process cartridge detachably mountable to the apparatus main body. A substance supply means for supplying a substance capable of exhibiting an adsorbing force to a lubricant to the surface of the image carrier is provided, and after the process cartridge is replaced with a new one, the image forming operation is started until the image forming operation is started. Image bearing A lubricant applying means for applying a lubricant to the surface and a control means for controlling the lubricant applying means and the substance supplying means so as to supply the substance to the surface of the image carrier. It is.

In the image forming apparatus according to the present invention, after the process cartridge is replaced with a new one, a lubricant is applied to the surface of the image carrier before the image forming operation is started. Supplies the substance to the surface of the image carrier. By applying this lubricant, the frictional force on the surface of the image carrier in the subsequent image forming operation is reduced in advance. Further, the substance supplied to the surface of the image carrier is blocked by the blocking member, adheres to the surface of the blocking member, or stays between the surface and the surface of the image carrier. Even when the process cartridge is replaced with a new one due to the above-mentioned attached or retained substance,
When the process cartridge has been replaced with a new one,
It is possible to prevent a temporary decrease in the consumption amount of the lubricant at the initial stage and to obtain a good image from the beginning of the output.

According to a second aspect of the present invention, in the image forming apparatus of the first aspect, a toner is used as the substance.

In the image forming apparatus of the present invention, toner used for actual image formation is used. Therefore, it is not necessary to prepare the above-mentioned substance.

According to a third aspect of the present invention, in the image forming apparatus of the first or second aspect, the damming member is a cleaning means for cleaning the surface of the image carrier or a thin film formed of a lubricant applied to the image carrier. The toner image forming means is also used as the substance supply means.

According to a third aspect of the present invention, in the image forming apparatus, a toner image forming means is used as the substance supplying means for supplying the toner as the substance, and a cleaning means or a lubricant thinning means is used as the damming member. Use means. By thus sharing, it is not necessary to separately provide the substance supply means, and cost can be reduced.

According to a fourth aspect of the present invention, in the image forming apparatus of the third aspect, an initial lubricant application mode is provided separately from an actual image formation mode.
The control unit is configured to execute the respective operations of the lubricant applying unit and the toner image forming unit.

In the image forming apparatus according to the present invention, when the image carrier is replaced with a new one, the initial lubricant application mode is operated to automatically form a toner image and lubricate with the toner. Remove the agent.

According to a fifth aspect of the present invention, in the image forming apparatus of the fourth aspect, the tone brightness of the toner image in the initial lubricant application mode is set lower than the maximum tone brightness in the actual image forming mode. It is characterized by the following.

According to the image forming apparatus of the present invention, the gradation lightness of the toner image in the initial lubricant application mode is
By lowering the maximum gradation brightness in the actual image forming mode, it is possible to minimize an increase in toner consumption in the initial lubricant application mode.

Here, if the tone brightness of the toner image in the initial lubricant application mode is too low, the toner adhesion density per unit area in the toner image becomes too low, and the amount of the lubricant removed together with the toner, That is, the consumption of the lubricant is also reduced. When the consumption of the lubricant decreases, the function of preventing the lubricant from being excessively applied may not be sufficiently exhibited.

According to a sixth aspect of the present invention, in the image forming apparatus of the fifth aspect, the gradation brightness of the toner image in the initial lubricant application mode is set to 50% or more of the maximum gradation brightness in the actual image forming mode. Is set.

In the image forming apparatus of the present invention, the gradation lightness of the toner image in the initial lubricant application mode is determined by:
Set to 50% or more of the maximum gradation brightness in the actual image forming mode. According to the experiments by the present inventors, the function of preventing excessive application of the lubricant is sufficiently exhibited if the gradation lightness in the initial lubricant application mode is 50% or more of the maximum gradation lightness in the image forming mode. It turned out to be. Therefore, in this image forming apparatus, it is possible to prevent the lubricant from being excessively applied while suppressing the toner consumption.

According to a seventh aspect of the present invention, in the image forming apparatus of the fourth, fifth or sixth aspect, when the initial lubricant application mode is operated, the toner image formed on the surface of the image carrier is transferred to the transfer member. And a control means configured to prevent the transfer of the image data.

In the image forming apparatus according to the present invention, since the toner image on the surface of the image carrier is not transferred to the transfer body during the operation of the initial lubricant application mode, all the toners constituting the toner image are lubricated. It can contribute to the consumption of the agent. Therefore, since the lubricant can be efficiently consumed, the operation time of the initial lubricant application mode can be reduced.

According to an eighth aspect of the present invention, in the image forming apparatus of the fourth, fifth, sixth, or seventh aspect, a new article detecting means for detecting a new article of the image carrier or the process cartridge, and the image forming means by the new article detecting means. After detecting a new carrier or a process cartridge, a control means for controlling the initial lubricant application mode to operate is provided.

In the image forming apparatus according to the present invention, when the image carrier or the process cartridge is replaced with a new one, the necessity of activating the initial lubricant application mode is automatically recognized by the new part detecting means. At the same time, the mode can be automatically activated.

[0030]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a color printer as an image forming apparatus will be described below. In the color printer according to the present embodiment, a one-component developer (hereinafter, referred to as toner) mainly including only toner is used.

First, the overall configuration of the color printer according to the present embodiment will be described. FIG. 1 is a cross-sectional view illustrating a schematic configuration of the entire color printer of the present embodiment. In this color printer, a flexible belt-shaped photoconductor (hereinafter, referred to as a photoconductor belt) 1 as an image carrier is provided in a state of being stretched between rotating rollers 2 and 3. The photosensitive belt 1 is driven by the rotation of the rotating rollers 2 and 3.
It rotates in the direction of arrow A (clockwise) in the figure.

Around the photoreceptor belt 1, a charging charger 4 as a charging unit for uniformly charging the surface of the photoreceptor belt 1 and an exposure unit as an exposure unit for forming an electrostatic latent image on the photoreceptor belt surface. A laser writing unit (hereinafter referred to as a writing unit) 5, a photoreceptor belt cleaning unit 15 as cleaning means for cleaning the surface of the photoreceptor belt 1, and yellow, cyan, magenta, and black color toners, respectively. A color developing device 6 as a rotary developing device integrally provided with the four developing devices described above is provided. The writing unit 5, the charging charger 4, and the color developing device 6
Thus, a toner image forming means for forming a toner image on the surface of the photoreceptor belt 1 is constituted.

On the right side of the photoreceptor belt 1 in the figure,
An intermediate transfer belt 10 as an intermediate transfer member is disposed so as to be in contact with the photosensitive belt. The intermediate transfer belt 10 is stretched between rotating rollers 11 and 12, and is rotated in the direction of arrow B (counterclockwise) in the figure by driving these rotating rollers. In FIG. 1, the intermediate transfer belt 10 is disposed in a state of being inclined to the upper left, and an extended portion on the lower left side is in contact with a portion of the photoreceptor belt 1 wound around the rotating roller 3. At this contact portion, the toner image formed on the photosensitive belt 1 is primarily transferred onto the intermediate transfer belt by a bias roller 13 provided as a primary transfer unit provided inside the intermediate transfer belt 10. The bias roller 13 is in contact with the back surface of the intermediate transfer belt 10 under predetermined conditions.

A portion of the intermediate transfer belt 10 wrapped around the upper rotation roller 11 among the rotation rollers 11 and 12 is provided with a secondary transfer member that can be brought into contact with and separated from the intermediate transfer belt. Transfer roller 14 as a cleaning unit and an intermediate transfer belt cleaning unit 1 for cleaning the secondary transfer residual toner remaining on the surface of the intermediate transfer belt
6 are provided. By the secondary transfer roller 14, the toner image formed on the intermediate transfer belt 10 is secondarily transferred onto a transfer paper 17A as a recording medium.

Further, the color printer according to the present embodiment includes a paper feed cassette 17 containing the transfer paper 17A,
Paper feed roller 18 for taking out the transfer paper from the paper feed cassette
A pair of transport rollers 19A and 19B for transporting the transfer paper taken out by the paper feed roller, and a pair of registration rollers 2 for feeding the transfer paper to the secondary transfer area at a predetermined timing.
0A and 20B, a fixing device 80 for fixing the toner image on the transfer paper after the completion of the secondary transfer, a pair of discharge rollers 81A and 81B for discharging the transfer paper passing through the fixing device, and a discharged transfer. A paper discharge stack unit 82 for stacking paper is provided.

In the present embodiment, the photoreceptor belt 1, the charging charger 4, the intermediate transfer belt 10, the belt cleaning device 16 and the like are integrally incorporated as a process cartridge 31, and the process cartridge 31 is a color printer. It is configured to be removable from the main body. The waste toner collecting container 15C is exchangeably incorporated into the process cartridge 31. Further, the cartridge exterior part of the registration roller 20B of the process cartridge 31 also has a function as a transfer paper transport guide.

The main body structure of the color printer includes a main body frame 9 as a stationary housing and a front frame 8 as a front housing. A paper feed cassette 17 is arranged below the main body frame portion 9, and as shown in FIG. 2, the front frame 8 is rotatably supported around a rotation support shaft 9a and has a structure that can be opened. This facilitates replacement of the process cartridge and the revolver developing device 6 based on their life, and further facilitates processing of jammed paper. At this time, the other imaging units are immobile, and no problems such as toner scattering and leakage occur.

Next, the constructions of the photosensitive belt cleaning unit 15 and the intermediate transfer belt cleaning unit 16 will be described with reference to FIG. Table 1 below shows a specific configuration of each member shown in FIG.

[0039]

[Table 1]

In FIG. 3, the photoreceptor belt cleaning unit 15 includes a cleaning blade 15A which is in constant contact with the surface of the photoreceptor belt 1 and scrapes off the primary transfer residual toner on the surface, and a cleaning blade 15A for scraping off the toner. And a waste toner collecting container 15C for collecting the waste toner.

In the photoreceptor belt cleaning unit 15, a brush roller 1 for the photoreceptor belt as a lubricant applying means for applying a lubricant to the surface of the photoreceptor belt is provided.
00 and a solid lubricant bar 101 are provided. The solid lubricant bar 101 is obtained by dissolving a lubricating oil additive containing zinc stearate as a main component, followed by cooling and solidification.
It is molded into a bar shape. The solid lubricant bar 101 is urged toward the brush roller 100 by a coil spring 102 and is in contact with the brush roller 100. In the present embodiment, in order to reduce the size and cost of the apparatus, there is no contact / separation mechanism for controlling the brush roller 100 so as to be able to contact / separate from the photosensitive belt 1. Is always in contact with the surface of the photoreceptor belt 1. After the primary transfer, the brush roller 100 is rotationally driven by a drive unit (not shown) to scrape the solid lubricant and apply the powdered lubricant to the photoreceptor belt 1. The lubricant applied to the photoreceptor belt 1 is thinned by the cleaning blade 15A which is also used as a lubricant thinning means for thinning the lubricant.

The intermediate transfer belt cleaning unit 16 includes a cleaning blade 16A which comes into contact with the surface of the intermediate transfer belt 10 and scrapes off the secondary transfer residual toner on the surface. This cleaning blade 16
A is provided by a solenoid (not shown) as a contact / separation mechanism.
During image formation, it is maintained at a position separated from the surface of the intermediate transfer belt 10, and is configured to come into contact with the surface of the intermediate transfer belt 10 as shown in the drawing only during cleaning after secondary transfer.

In the cleaning unit 16 for the intermediate transfer belt, a brush roller 110 for the intermediate transfer belt and a solid lubricant bar 111 are provided as a lubricant applying means for applying a lubricant to the surface of the intermediate transfer belt. Have been. The solid lubricant bar 111 is the same as the solid lubricant bar 101 for the photoreceptor belt, and is in contact with the brush roller 110 by its own weight. Also, the brush roller 1
After the secondary transfer, the secondary transfer is rotationally driven by a driving unit (not shown) to scrape off the solid lubricant bar 111 and apply the powdered lubricant to the intermediate transfer belt 10. The lubricant applied to the intermediate transfer belt 10 is applied to the cleaning blade 1 which is also used as a lubricant thinning means.
The film is thinned by 6A.

Next, the image forming operation of the printer will be described. In FIG. 1, after the surface of a photoreceptor belt 1 is uniformly charged by a charger 4, it is scanned and exposed by a writing unit 5 based on image information to carry an electrostatic latent image. This image information is monochrome image information obtained by decomposing a desired full-color image into yellow, cyan, magenta, and black color information. Further, the scanning exposure,
A laser beam L emitted from a semiconductor laser (not shown) based on the image information is scanned and optical path adjusted by an optical device.

The single-color electrostatic latent image carried on the surface of the photoreceptor belt 1 is developed in a single color with a yellow, cyan, magenta or black toner by a color developing device 6, and a predetermined color is formed on the photoreceptor belt 1. Images are sequentially formed. The toner images of each color formed on the photosensitive belt 1 are transferred to the intermediate transfer belt 1 that rotates in synchronization with the rotation of the photosensitive belt 1.
On the other hand, the image is sequentially transferred onto a single color of yellow, cyan, magenta, and black with a predetermined transfer bias applied to the bias roller 13.

The superimposed toner image on the intermediate transfer belt 10 is transferred onto the transfer paper 17a from the paper supply cassette 17 via the paper supply roller 18, the conveyance roller pairs 19A and 19B, and the registration rollers 20A and 20B to the transfer section. Are collectively transferred by the secondary transfer roller 14. After the transfer, transfer paper 1
7a is fixed by the fixing device 80 to complete a full-color image, and the print image is discharged to the discharge stack unit 82 via the discharge roller pairs 81A and 81B.

After the primary transfer, the surface of the photoreceptor belt 1 is cleaned of residual toner by the cleaning blade 15A.
0 means that the lubricant is applied. After the secondary transfer, the surface of the intermediate transfer belt 10 is cleaned of residual toner by the cleaning blade 16A abutting on the belt surface by a solenoid (not shown), and a lubricant is applied by a brush roller 110 for the intermediate transfer belt. Is done.

The conditions for applying the lubricant to the photoreceptor belt 1 in the above-described image forming process are as follows.
The amount is set so that the amount of the lubricant attached to the surface can always be kept within a certain range, that is, within a range in which the supply and consumption of the lubricant can be balanced. The amount of the lubricant attached can be indirectly determined by measuring the static friction coefficient of the surface of the photoreceptor belt 1. In the present embodiment, the lubricant application conditions are set so that the static friction coefficient of the surface of the photoreceptor belt 1 is in the range of 0.21 to 0.3, more preferably 0.21 to 0.25. I have. By setting in this manner, the occurrence of a bug-like image due to an excessively large adhesive force between the surface of the photoreceptor belt 1 and the toner when the amount of adhesion of the lubricant is too large as described above is prevented. In addition, when the amount of the lubricant attached is too small, poor development due to poor charging of the toner can be prevented, and a good image can be obtained.

However, the process cartridge 31
When the is replaced with a new one, as described above, the lubricant may be temporarily over-applied.

Therefore, in the color printer according to the present embodiment, the image forming mode in which the above-described image forming step is performed, and separately from the image forming mode, when the photosensitive belt 1 is replaced with a new one, An initial lubricant application mode for applying a lubricant is provided. This mode switching
For example, the operator can select an image forming mode or an initial lubricant application mode by operating a mode changeover switch (not shown) provided on the operation panel. This mode changeover switch is connected to a system control board shown in FIG.

The system control plate controls the entire color printer, and includes a photosensitive belt driving motor for the rotating rollers 2 and 3 of the photosensitive belt 1, a charging charger 4, the writing unit 5, The drive unit of the color developing device 6, the brush roller 10 for the photosensitive belt
0, an intermediate transfer belt drive motor for the rotating rollers 11 and 12 of the intermediate transfer belt 10, a solenoid as a mechanism for contacting and separating the belt cleaning blade 16A, a power supply for applying a transfer bias to the bias roller 13, Various driving units in the color printer are connected. In the present embodiment, the drive motor for the photoreceptor belt brush roller 100, the color developing device 6, the fixing device 80, and the paper transport unit that transports the transfer paper 17a to the fixing device 80 are the same. The rotating rollers 2 and 3 of the photoreceptor belt and the rotating rollers 11 and 12 of the intermediate transfer belt are connected to the same driving motor.

Next, the control operation in the initial lubricant application mode will be described. In the initial lubricant application mode, a lubricant is applied to the photoreceptor belt 1 by the photoreceptor belt brush roller 100, and then the writing unit 5, the charging charger 4, the color developing device 6, and the like are applied to the surface of the photoreceptor belt 1. A toner image having a predetermined pattern is formed, and then the lubricant is removed together with the toner by the cleaning blade 15A. In the present embodiment, a solid image pattern having a width of 330 mm (A3 width) × a length of 420 mm is used as the predetermined pattern, and a toner image of the pattern is formed for each of the four colors of yellow, cyan, magenta, and black. Specifically, when the initial lubricant application mode is started, first, the rotational drive of the photosensitive belt 1 and the rotational drive of the brush roller 100 for the photosensitive belt are started, and the lubricant is applied to the surface of the photosensitive belt 1. Is done.
In synchronization with this, the surface of the photoreceptor belt 1 is uniformly charged by the charger 4. Next, the writing unit 5 forms yellow, cyan, magenta, and black electrostatic latent images based on the predetermined pattern on the surface of the photoreceptor belt where the lubricant is applied. Next, each electrostatic latent image is converted into yellow,
Monochromatic development is performed with cyan, magenta, or black toner, and the toner images of the predetermined pattern are sequentially formed on the surface of the photoreceptor belt 1. The surface of the photoreceptor belt 1 on which the toner image has been formed is placed on the cleaning blade 15.
Cleaning is performed by A. In the present embodiment,
The above operation is set to be performed twice consecutively. It should be noted that normal process control may be set so as to be continuous with the initial lubricant application mode.

In the above initial lubricant application mode,
By applying the lubricant, the frictional force on the photoreceptor belt surface in the subsequent image forming operation is reduced in advance. The toner supplied to the surface of the photoreceptor belt 1 is blocked by the cleaning blade 15A, and the toner is supplied to the cleaning blade 15A.
Attach to the surface, or this surface and photoreceptor belt 1
Keep between the surface. The adhered or retained toner is a substance capable of exerting an adsorbing force on the lubricant, and therefore, a part of the lubricant passing through the cleaning blade 15A is adsorbed and removed from the surface of the photoreceptor belt 1. . That is, this part of the lubricant is consumed. As a result, even when the process cartridge is replaced with a new one, the same state as when the image forming process is repeated for a certain number of times or more, and the initial temporary consumption of lubricant when the process cartridge is replaced with a new one. And a good image can be obtained from the beginning of output.

From the viewpoint of suppressing the toner consumption,
In the initial lubricant application mode, the gradation brightness of the toner image formed as the predetermined pattern is adjusted to a maximum value of the toner image formed in the image forming mode within a range in which the supply amount and the consumption amount of the lubricant can be balanced. It is desirable to set lower than the gradation lightness. In the color printer according to the present embodiment, an experiment was performed in which the gradation brightness was changed in the latent image forming step by the writing unit 5.
It has been confirmed that the above balance can be maintained even when the brightness is reduced to 50% of the maximum gradation brightness in the image forming mode. Therefore, for example, by adjusting the exposure amount so that the gradation brightness of the toner image in the initial lubricant application mode is 50% or more of the maximum gradation brightness in the actual image forming mode, the toner consumption is suppressed. While
It is possible to prevent the lubricant from being excessively applied.

In the initial lubricant application mode, it is desirable to turn off a power supply (see FIG. 4) for applying a transfer bias to the bias roller 13. As a result, the toner image on the surface of the photoreceptor belt 1 is not transferred, so that all the toner constituting the toner image can contribute to the consumption of the lubricant. Therefore, since the lubricant can be efficiently consumed, the operation time of the initial lubricant application mode can be reduced.

In the above embodiment, the case where the operator selects the image forming mode and the initial lubricant application mode has been described as an example. However, a new article detecting means for detecting a new process cartridge in the color printer is provided. It is also possible to adopt a configuration in which the initial lubricant application mode is controlled based on the new product detection signal. As the detecting means, for example, a fin may be provided on the photoconductor brush roller 100, and a one-tooth gear (not shown) provided on a roller shaft of the brush roller 100 and a photo interrupter may be used. More specifically, the fin and the gear are engaged with each other. If the gear does not rotate, it is determined that the fin is new. FIG. 5 shows a flowchart for detecting the process cartridge (PCU). When a new process cartridge is detected, the operation after the detection of a new PCU, that is, the initial lubricant application mode is automatically started. According to this method, when a new process cartridge is mounted, the necessity of executing the initial lubricant application mode is automatically recognized, and the mode can be automatically operated.

Hereinafter, a new process cartridge is mounted on the color printer of the present embodiment, and the amount of toner adhering to the cleaning blade 15A during the operation of the initial lubricant application mode is changed. The result of evaluating the rank of white streaks will be described. Since it is difficult to accurately measure the actual amount of toner adhering to the cleaning blade 15A, the amount of toner removed and collected by the cleaning blade 15A, specifically, the brush roller for the photosensitive belt The amount of toner adhering to 100 (hereinafter, referred to as the amount of toner soiled) was measured.

In FIG. 6, the horizontal axis of the graph indicates the amount of brush toner contamination (g), and the vertical axis indicates the rank of white stripes on the image at the beginning of output. The higher the number of white streaks, the smaller the number of white streaks, indicating a better image. The larger the brush soiling amount, that is, the cleaning blade 15
It can be seen that the greater the amount of toner attached to A, the less the occurrence of white stripes in the image at the beginning of output. It should be noted that since the toner image pattern for determination used in this evaluation is a very fine dither pattern, there is no problem even in actual user use if the rank is about 3.5 or more in this evaluation. From the above results, in the color printer of the present embodiment, when the initial lubricant application mode is activated after the detection of a new process cartridge, the amount of the brush stain is 10%.
By setting the lubricant application conditions to about g, it was confirmed that white streak-like abnormal images were prevented from occurring from the initial stage of image output, and good images could be obtained.

In the above embodiment, the case where the toner is supplied to the surface of the photoreceptor belt 1 by providing the initial lubricant application mode and forming a toner image has been described as an example. However, the present invention is not limited to this. For example, a substance supply means for supplying a substance capable of exerting an adsorption force to the lubricant to the surface of the image carrier is separately provided, and after the process cartridge is replaced with a new one, until the image forming operation is started. The lubricant application means and the substance supply means may be controlled so that a lubricant is applied to the surface of the image carrier, and the substance is supplied to the surface of the image carrier. . In this case, it is preferable to use, for example, a transparent polyol-based powder having the same component as that of the toner, as the substance capable of exhibiting the adsorbing power to the lubricant. Such a powder is not noticeable even if scattered. In addition, various types of materials (such as polyester) used for toner and the like can be considered.

[0060]

According to the image forming apparatus of the first to eighth aspects, when the process cartridge is replaced with a new one, a temporary decrease in the consumption of the lubricant at the initial stage is prevented, and a good output is obtained from the beginning of the output. Images can be obtained. In particular, claim 2
According to the image forming apparatus described above, there is no need to specially prepare the above substance. Further, according to the image forming apparatus of the third aspect, it is not necessary to separately provide the substance supply means and the like, and the cost can be reduced. Further, according to the image forming apparatus of the fourth aspect, when the image carrier is replaced with a new one, the application of the lubricant and the formation of the toner image for appropriately consuming the lubricant can be automatically performed. it can. According to the image forming apparatus of the fifth aspect, it is possible to minimize an increase in toner consumption in the initial lubricant application mode. According to the image forming apparatus of the sixth aspect, it is possible to prevent the lubricant from being excessively applied while suppressing the toner consumption. According to the image forming apparatus of the seventh aspect, since the lubricant can be efficiently consumed, the operation time of the initial lubricant application mode can be shortened. Further, according to the image forming apparatus of the eighth aspect, it is possible to automatically recognize the necessity of operating the initial lubricant application mode and to automatically operate the mode.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a schematic configuration of a color printer according to an embodiment.

FIG. 2 is a cross-sectional view illustrating a state in which a front frame of the color printer is opened.

FIG. 3 is an enlarged view around a photoreceptor belt and an intermediate transfer belt.

FIG. 4 is a control block diagram of the color printer.

FIG. 5 is a detection flowchart of a process cartridge (PCU).

FIG. 6 is a graph showing the relationship between the amount of soiled brush toner and the rank of white stripes on an image.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photoconductor belt 2, 3 rotation roller 4 charging charger 5 writing unit 6 color developing device 8 front frame 9 main body frame section 10 intermediate transfer belt 11, 12 rotation roller 13 bias roller 14 secondary transfer roller 15 for photoconductor belt Cleaning unit 15A Cleaning blade 16 Intermediate transfer belt cleaning unit 16A Cleaning blade 17 Paper feed cassette 17A Transfer paper 18A, B paper feed roller 19A, B transport roller 20A, B Registration roller 31 Process cartridge 80 Fixing device 81A, B paper discharge roller 82 Discharge Stack 100 Brush Roller for Photoconductor Belt 101 Solid Lubricant Bar for Photoconductor Belt 102 Coil Spring 110 Brush Roller for Intermediate Transfer Belt 111 Solid Lubricant for Intermediate Transfer Belt Agent bar

Claims (8)

[Claims] An image carrier, a toner image forming means for forming a toner image on the surface of the image carrier, a transfer means for transferring the toner image formed on the surface to a transfer object, and the image carrier. A damming member for damping toner at the time of image formation in proximity to or in contact with the surface, and a lubricant applying means for applying a lubricant to the surface; and at least the image carrier, the lubricant applying means, In an image forming apparatus in which a damming member is integrated and configured as a process cartridge that can be detachably attached to an apparatus main body, a substance capable of exhibiting an adsorption force with respect to the lubricant is provided on the surface of the image carrier. After supplying the substance supply means, and after replacing the process cartridge with a new one, by the time the image forming operation is started, a lubricant is applied to the surface of the image carrier, and the substance is transferred to the image carrier. Supply to body surface An image forming apparatus provided with control means for controlling the lubricant application means and the substance supply means. 2. An image forming apparatus according to claim 1, wherein a toner is used as said substance. 3. The image forming apparatus according to claim 1, wherein said damming member is a cleaning means for cleaning a surface of said image bearing member or a lubricant thin film for thinning a lubricant applied to said image bearing member. Wherein the toner image forming means is also used as the substance supply means. 4. An image forming apparatus according to claim 3, wherein an initial lubricant application mode is provided separately from an actual image formation mode, and in said initial lubricant application mode, said lubricant applying means and said toner image forming means are provided. An image forming apparatus, wherein the control unit is configured to execute each operation. 5. The image forming apparatus according to claim 4, wherein the tone brightness of the toner image in the initial lubricant application mode is set lower than the maximum tone brightness in the actual image forming mode. Forming equipment. 6. The image forming apparatus according to claim 5, wherein the tone brightness of the toner image in the initial lubricant application mode is set to 50 times the maximum tone brightness in the actual image forming mode.
%. 7. The image forming apparatus according to claim 4, wherein the toner image formed on the surface of the image carrier is not transferred to the transfer body during the operation of the initial lubricant application mode. An image forming apparatus comprising a control unit configured as described above. 8. An image forming apparatus according to claim 4, wherein said new detecting means detects a new product of said process cartridge, and said initial lubrication after detecting the new product of said process cartridge by said new product detecting means. An image forming apparatus, comprising: a control unit that controls so as to operate the agent application mode.