JP2011064735A - Apparatus and system for forming image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which includes a cleaning device which can reduce wear to necessary minimum while suppressing filming on a photoreceptor in a high speed electrophotographic device used for printing on continuous paper, and to provide an image forming system. <P>SOLUTION: The image forming apparatus includes the photoreceptor, a charger for charging the photoreceptor, an exposure device for forming a latent image by exposing the photoreceptor, a developing device for forming a visible image by developing a latent image on the photoreceptor with toner, a transfer device for transferring the visible image to paper, a fixing device for applying heat to paper with the visible image transferred thereto, thereby fixing the visible image, and the cleaning device for cleaning the photoreceptor. In the image forming apparatus, the cleaning device includes the function of rotating a cleaning brush in a reverse direction to a photoreceptor, thereby removing residual transfer toner on the photoreceptor, and the function of sliding against the surface of the photoreceptor. The number of rotations of the cleaning brush is varied according to a condition for a printing process. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an image forming apparatus and an image forming system.

An electrophotographic apparatus performs development by electrostatically attaching toner to a latent image formed on the surface of a photoreceptor with a laser beam or the like, transferring the toner to a recording material such as paper, and heating the transferred toner. The image is fixed and printed by this.
In such an electrophotographic apparatus, a cleaning brush or a cleaning blade is used to remove unnecessary toner and foreign matters adhering to the photoreceptor.

  Since these cleaning devices have the force to mechanically rub the surface of the photoreceptor, they also have the ability to suppress filming.

  Similarly, the magnetic brush of the developing roll has the ability to suppress filming by mechanical rubbing force.

  Here, “filming” is a phenomenon in which an additive such as silica contained in the toner is released from the toner main body due to mechanical stress or the like during the image forming process, and is thinly adhered to the surface of the photoreceptor.

  According to the observations by the present inventors, it is understood that the conditions under which filming is likely to occur are cases where the toner concentration in the developer is high, the photoconductor temperature is high, and the amount of toner attached to the photoconductor is large. Yes. When this filming occurs, the adhesion force of the toner on the surface of the photoreceptor is weakened, and problems such as white spots appear in the image.

  The filming suppression effect of the cleaning brush and the developing roll is that the relative circumferential speed difference is increased by rotating the photosensitive brush in the opposite direction at the portion opposite to the rotation direction of the photosensitive member, and the rubbing force against the photosensitive member surface is increased. Thus, the ability to suppress filming becomes higher.

  Conventionally, as a method for preventing filming of a photoconductor, a method of preventing filming by rotating a cleaning brush and a developing roll in a direction opposite to the photoconductor in the opposite direction is disclosed (Patent Document 1). .

  However, if the rubbing force with respect to the surface of the photoconductor is increased, the amount of the film on the photoconductor is also increased. Therefore, if filming is suppressed, there arises a problem that the life of the photoconductor is shortened.

High-speed electrophotographic apparatuses that use continuous paper with a printing speed of 700 mm / sec or more have mainly used a photoreceptor in which a selenium-based material is deposited on an aluminum alloy drum-shaped tube. Since the selenium-based photoreceptor has a metal photosensitive layer, it has a hard surface and excellent wear resistance compared to an organic photosensitive layer, and is advantageous for abrasion of the photosensitive layer.
However, recently, there is a tendency to change the material of the photosensitive layer from selenium to organic in the electrophotographic method in the high-speed field from the viewpoint of environment.

  Therefore, it is necessary to consider the wear of the organic photoreceptor along with preventing filming.

  The lifetime of the selenium-based photoconductor of a high-speed electrophotographic apparatus using continuous paper is 3 million pages or more. Even if the material is changed to an organic photoconductor, the base part of the aluminum alloy does not change, and the manufacturing cost of the photoconductor does not vary greatly.

  Here, as disclosed in Patent Document 1, it is possible to reinforce the rubbing force and prevent filming by rotating the developing roll and the cleaning brush in the direction opposite to the photoconductor. In the case of a medium and low speed cut sheet printer, the life of the photoreceptor is generally several hundreds of thousands of pages. As disclosed in Patent Document 1, it is possible to achieve both the prevention of filming and the life due to wear. .

  However, for a high-speed electrophotographic apparatus using continuous paper, abrasion of the photosensitive layer becomes a problem in order to have a life of 3 million pages or more.

  An electrophotographic apparatus using continuous paper includes a system in which two continuous printers are connected to print one continuous paper. In that case, since the paper that has been heat-fixed in the first unit contacts the second photoconductor, the temperature of the second photoconductor is necessarily higher than that of the first photoconductor. There is a problem that filming is easy under the same cleaning conditions as the first stage.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to prevent wear in a high-speed electrophotographic apparatus for printing continuous paper while suppressing filming of the photoreceptor. An object of the present invention is to provide an image forming apparatus and an image forming system including a cleaning device that can be minimized.

  In order to solve the above-mentioned problems, an invention according to claim 1 is an electrophotographic apparatus comprising: a drum-shaped photoreceptor having a photosensitive layer of an organic material; a charging device that charges the photoreceptor; and the photoreceptor. An exposure device that forms a latent image by exposure, a developing device that develops the latent image on the photoconductor with toner to form a visible image, a transfer device that transfers the visible image onto a sheet, and the movable device. An image forming apparatus having a fixing device that heats and fixes a sheet onto which a visual image has been transferred, and a cleaning device that cleans the photoreceptor after the transfer, the cleaning device including a cleaning brush, The cleaning brush is rotated in the opposite direction with respect to the photoconductor to remove transfer residual toner on the photoconductor and to rub the surface of the photoconductor. Characterized in that varying the rotation speed of over training brush.

  Here, the toner concentration is a mixing ratio of the toner in the carrier in the two-component development using the carrier and the toner which are magnetic particles.

  According to a second aspect of the present invention, in the first aspect of the present invention, the cleaning device varies the number of rotations of the cleaning brush based on the toner concentration of the developer in the developing device. To do.

  According to a third aspect of the present invention, in the first aspect of the invention, the cleaning device varies the number of rotations of the cleaning brush based on the temperature of the developer in the developing device or the temperature of the photoconductor. It is characterized by that.

  Note that the photoconductor is always in contact with the developer via the magnetic brush of the developing roll, and the developer is constantly circulating in the developing device during printing. Therefore, the temperature of the photoreceptor is almost the same as the temperature of the developer. Therefore, the temperature of the developer may be detected instead of the photoreceptor.

  According to a fourth aspect of the present invention, in the first aspect of the invention, the cleaning device may vary the number of rotations of the cleaning brush based on the amount of toner adhered per unit area of the photoconductor. Features.

  According to a fifth aspect of the present invention, in the first aspect of the present invention, the cleaning device is configured such that the number of rotations of the cleaning brush, the toner concentration of the developer in the developing device, the temperature of the developer, or the photosensitivity. It is characterized by being variable based on a combination of body temperatures.

  Here, the temperature of the developer may be detected instead of the photoconductor.

  According to a sixth aspect of the present invention, in the first aspect of the present invention, the cleaning device is configured such that the number of rotations of the cleaning brush, the toner concentration of the developer in the developing device, and the toner on the photoconductor. It is variable based on the combination of the amount of adhesion.

  According to a seventh aspect of the present invention, in the first aspect of the invention, the cleaning device is configured such that the number of rotations of the cleaning brush, the temperature of the developer in the developing device or the temperature of the photoconductor, and the photoconductor. It is characterized in that it can be varied based on the combination of the above toner adhesion amounts.

  Here, the temperature of the developer may be detected instead of the photoconductor.

  According to an eighth aspect of the present invention, in the first aspect of the invention, the cleaning device is configured such that the number of rotations of the cleaning brush, the toner concentration of the developer in the developing device, and the developer in the developing device. Or the temperature of the photosensitive member, and a combination of the toner adhesion amount on the photosensitive member.

  Here, the temperature of the developer may be detected instead of the photoconductor.

  The invention described in claim 9 is characterized in that printing is performed on a single sheet of continuous paper in the invention described in claim 1.

  According to a tenth aspect of the present invention, the image forming apparatus according to the first aspect is arranged in series, and after one sheet of continuous paper is printed on one side of the image forming apparatus, the continuous paper is formed on the image forming apparatus. Printing is continuously performed on the other side of the apparatus.

  According to the present invention, since the rotation speed of the cleaning brush is adjusted according to the printing process conditions, the amount of wear of the photoconductor can be minimized while suppressing filming, and the life of the photoconductor is extended. Can be achieved.

1 is an explanatory diagram showing a schematic configuration of an example of a main part of a printer as an image forming apparatus according to an embodiment of the present invention. 1 is a conceptual diagram illustrating an example of an image forming system according to the present invention.

[Characteristic]
In the present invention, based on the minimum number of rotations of the cleaning brush that can remove unnecessary toner on the surface of the photoconductor with a cleaning brush, the toner density of the developer, the temperature of the photoconductor, and the unit area per unit area of the photoconductor Depending on the toner adhesion amount or a combination thereof, the number of rotations of the cleaning brush is increased to an appropriate number of rotations that can prevent filming under conditions where filming is likely to occur. Therefore, it is possible to minimize the wear of the photosensitive member due to the prevention of filming.

[Embodiment 1]
FIG. 1 is an explanatory diagram showing a schematic configuration of an example of a main part of a printer as an image forming apparatus according to an embodiment of the present invention.
This printer includes a drum-shaped organic photoreceptor (hereinafter referred to as “photoreceptor”) 1, a charger 2, a laser exposure device 3, a developing device 4, a developing roll 5, a transfer device 6, a charge eliminating device 7, A cleaning device 10 and a fixing device 30 are included. The cleaning device 10 includes a case 9 and a cleaning brush 8.

  The photoreceptor 1 rotates in the clockwise direction in the figure, and the surface is charged by the charger 2, and a latent image is formed on the photoreceptor 1 by exposure from the laser exposure device 3. A toner 11 is attached to the latent image by the developing roll 5 of the developing device 4 and is transferred onto the paper 12 by the transfer device 6. Then, the paper 12 is conveyed to the heating type fixing device 30 to fix the image.

  On the other hand, the photoreceptor 1 after image transfer is neutralized by the neutralization device 7 and the unnecessary toner 17 remaining on the surface without being transferred is removed by the cleaning brush 8.

The toner removed by the cleaning brush 8 is collected in a waste toner bottle (not shown) by an exhaust system (not shown).
In the present embodiment, the developing device 4 has a toner concentration detecting device 13 for detecting the toner concentration in the developer (not shown), and a thermometer 15 connected to a thermocouple 14 for detecting the developer temperature. Further, a toner adhesion amount detection device 16 for detecting the toner adhesion amount per unit area on the photoreceptor 1 is provided.

  The toner density is adjusted to obtain a predetermined printing density according to the printing pattern, ambient temperature and humidity, and the like. The method for detecting the toner concentration is not particularly limited, but the magnetic permeability detection method is used here. A method for detecting the developer temperature is not particularly limited, but a thermocouple is used here. Since the magnetic brush is in contact with the photosensitive member 1, the developer 18 has substantially the same temperature as the photosensitive member 1.

  The temperature of the photosensitive member 1 varies depending on the ambient temperature around the printer, or the second unit in the case of an image forming system that connects two printers for printing passes through the fixing device 30 of the first printer. Therefore, the sheet 12 is naturally heated, and the heat is transmitted to the photosensitive member 1 of the second printer, and the temperature of the second printer becomes higher.

  Similarly, a method for detecting the toner adhesion amount per unit area on the photosensitive member 1 is not particularly limited, but here, a method for detecting light reflectance is used.

  The toner concentration detection device 14 that detects the toner concentration and the thermocouple 14 that detects the temperature of the developer are positioned substantially in the center in the width direction of the paper 12.

  On the other hand, the toner adhesion amount detection device for detecting the toner adhesion amount per unit area on the photosensitive member 1 is located near the end in the width direction of the paper 12. This is because, as a feature of a printer that prints on continuous paper, a dummy for measuring the amount of adhesion cannot be printed in the gap between the papers 12 like cut papers. Print.

  The rotation direction of the developing roller 5 is the same as that of the photosensitive member 1 at the facing portion, and keeps a predetermined distance from the photosensitive member 1, and rubs the photosensitive member 1 while the magnetic brush of the developing roller 5 rotates to remove the toner 11. Adhere. The cleaning brush 8 has a positional relationship in which the brush tip contacts the photoconductor 1 and rotates in the opposite direction to the photoconductor 1 at the opposing portion to remove unnecessary toner 17 remaining after transfer and to rub the photoconductor 1. .

  As a material for the cleaning brush 8, there can be considered a method in which unnecessary toner is mechanically or potentialally attracted and removed. However, when the toner is mechanically removed, an insulating polyester is used. Nylon is generally used. Here, a brush made of 100% nylon was used.

  There are two mechanisms for suppressing filming: the developing roll 5 and the cleaning brush 8. Among these, the developing roll 5 has a role of adhering toner to the photosensitive member 1 and has a certain effect of suppressing filming. The developing condition is the rotation speed, magnetic force, or distance from the photosensitive member. Thus, the filming suppression effect can be adjusted.

  However, since changing these development conditions leads to a change in image quality, it is necessary to fix it in effect. Further, the higher the filming suppression effect, the faster the photoconductor 1 is worn, and the life of the photoconductor 1 is shortened. Therefore, it is necessary to fix the photoconductor 1 to an appropriate condition.

On the other hand, since the cleaning brush 8 is not directly related to the image quality, the rotation speed can be changed even during printing by minimizing the rotation speed at which unnecessary toner 17 remaining after transfer can be removed. Here, as an example, the lower limit of the rotational speed at which unnecessary toner can be removed is 1300 rpm.
Therefore, as an example, the number of rotations of the cleaning brush 8 is variable in two stages of 1500 and 2500 rpm, and can be adjusted according to the printing process conditions.

  Further, the toner is mainly composed of a general polyester resin, and a material mainly composed of a general polycarbonate resin is used for the surface of the photoreceptor. In this example, the printing speed was 1650 mm / sec, the photosensitive member size was φ260 mm, and the cleaning brush size was φ90 mm.

[Embodiment 2]
The image forming apparatus according to the present embodiment is the image forming apparatus having the configuration shown in FIG. 1. When the toner density is detected by the toner density detecting device 13 and the toner density is high, the rotation speed of the cleaning brush 8 is set. There is a method of increasing the speed and decreasing the rotational speed of the cleaning brush 8 when the toner density is low. Table 1 shows an example of the relationship between the toner density that does not cause filming and the rotational speed of the cleaning brush 8.

However, the temperature of the developer 18 is 38 ° C., and the toner adhesion amount per unit area on the photoreceptor 1 is 0.5 mg / cm ² . As shown in Table 1, when the toner concentration is 4% to less than 6%, filming does not occur when the rotational speed of the cleaning brush 8 is 1500 rpm, and when the toner concentration is 6 to 8%, filming occurs at 1500 rpm. However, it does not occur at 2500 rpm.

  Therefore, the rotation speed of the cleaning brush 8 is preferably controlled to 1500 rpm when the toner concentration is less than 4% to 6%, and 2500 rpm when the toner concentration is 6 to 8%.

[Embodiment 3]
The image forming apparatus according to the present embodiment is the image forming apparatus having the configuration shown in FIG. 1. When the temperature of the developer is detected by the thermocouple 14 and the thermometer 15 and the temperature is high, the cleaning brush 8 A method of increasing the number of rotations and decreasing the number of rotations of the cleaning brush 8 when the temperature is low is provided. However, the toner concentration is 5%, and the toner adhesion amount is 0.5 mg / cm ² .
Table 2 shows an example of the relationship between the temperature of the developer 18 and the number of rotations of the cleaning brush 8 that does not cause filming.

As shown in Table 2, when the developer temperature is 35 ° C. to less than 40 ° C., the cleaning brush 8 rotates at 1500 rpm and no filming occurs. Filming occurs at 1500 rpm when the developer temperature is in the range of 40 ° C. to 45 ° C., but does not occur at 2500 rpm.
Therefore, the rotation speed of the cleaning brush 8 is preferably controlled to 1500 rpm when the developer temperature is 35 ° C. to less than 40 ° C. and 2500 rpm when the developer temperature is 40 ° C. to 45 ° C.

[Embodiment 4]
The image forming apparatus of the present embodiment is an image forming apparatus having the configuration shown in FIG. 1, and the toner adhesion amount per unit area on the photosensitive member 1 is detected by the toner adhesion amount detection device 16. When the amount is large, the number of rotations of the cleaning brush 8 is increased, and when the amount of adhesion is small, the number of rotations of the cleaning brush 8 is decreased.
However, the toner concentration is 5% and the developer temperature is 38 ° C.
Table 3 shows an example of the relationship between the toner adhesion amount per unit area and the rotation speed of the cleaning brush 8 that does not cause filming.

As shown in Table 3, when the toner adhering amount is less than ^{0.4mg / cm 2 ~0.6mg / cm 2} , the rotational speed of the cleaning brush 8 does not occur filming at 1500 rpm, the toner adhering amount is 0.6 mg / cm ² ~0.8mg / cm ² in filming at 1500rpm occurs, but does not occur in 2500rpm.

Therefore, the rotation speed of the control of the cleaning brush 8, the toner adhering amount is set to 1500rpm less than ^{0.4mg / cm 2 ~0.6mg / cm 2} , when the 0.6mg / cm ² ~0.8mg / cm ² to 2500rpm .

[Embodiment 5]
The image forming apparatus of the present embodiment is an image forming apparatus having the configuration shown in FIG. 1, and the toner concentration in the developer and the temperature of the developer 18 are respectively determined by the toner concentration detecting device 13 and the thermocouple 14. It is detected, the ease of filming is calculated from both values, and fed back to the rotational speed of the cleaning brush 8.
However, the toner adhesion amount is 0.5 mg / cm ² .
Table 4 shows an example of the relationship between the combination of toner density and developer temperature and the lower limit of the rotational speed of the cleaning brush 8 that can prevent the occurrence of filming.

[Embodiment 6]
The image forming apparatus of the present embodiment is an image forming apparatus having the configuration shown in FIG. 1, and the toner concentration detecting device 13 detects both the toner concentration in the developer and the toner adhesion amount per unit area on the photoreceptor 1. And the toner adhesion amount detection device 16, the ease of filming is calculated from both values, and fed back to the rotational speed of the cleaning brush 8.
Table 5 shows an example of the relationship between the toner density, the combination of the amount of toner adhering to the photoreceptor 1 per unit area, and the lower limit of the rotational speed of the cleaning brush 8 that prevents filming.

[Embodiment 7]
The present embodiment is an image forming apparatus having the configuration shown in FIG. 1, wherein the temperature of the developer and the amount of toner adhered to the photosensitive member 1 per unit area are determined by a thermocouple 14, a toner adhesion amount detecting device 16, and the like. , And the ease of filming is calculated from both values and fed back to the rotational speed of the cleaning brush 8.
However, the toner density is 5%.
Table 6 shows an example of the relationship between the developer temperature, the combination of the amount of toner adhering to the photoreceptor 1 per unit area, and the lower limit of the rotational speed of the cleaning brush 8 that prevents filming.

[Embodiment 8]
The present embodiment is an image forming apparatus having the configuration shown in FIG. 1, and the toner density is determined by three points: the toner density in the developer, the temperature of the developer, and the toner adhesion amount per unit area. This is detected by the detection device 13, the thermocouple 14, and the toner adhesion amount detection device 16, and the ease of filming is calculated from three values and fed back to the rotational speed of the cleaning brush 8.
Table 8 shows an example of the relationship between the toner concentration in the developer, the temperature of the developer, the amount of toner adhesion to the photoreceptor 1 per unit area, and the rotation speed lower limit of the cleaning brush 8 that prevents filming. Show.

[Embodiment 9]
FIG. 2 is a conceptual diagram showing an example of an image forming system according to the present invention.
The image forming system shown in FIG. 1 includes a first printer 20 and a second printer 21 which are image forming apparatuses having the configuration shown in FIG. The flowing paper 12 is first printed by the first printer 20, continuously printed by the second printer 21, and taken up by the rewinder 22.

  Since the paper 12 that has passed through the fixing device of the first printer 20 is carried into the second printer 21, the temperature of the photosensitive member, that is, the temperature of the developer is higher than that of the first printer 20. As shown in the fourth and seventh embodiments, each of the first printer 20 and the second printer 21 has a rotational speed of the cleaning brush 8 that can prevent filming at each temperature. Therefore, it is possible to minimize the lifetime reduction due to the abrasion of the photosensitive layer of the photoreceptor 1.

  By arranging two image forming apparatuses, double-sided printing, two-color printing, and the like are possible.

[Function and effect]
In the present embodiment, since the rotation speed of the cleaning brush is adjusted according to the printing process conditions, when the toner density is high, the rotation speed of the cleaning brush is increased, and when the toner density is low. Since the number of rotations of the cleaning brush is lowered, filming can be suppressed, the amount of wear of the photoconductor can be minimized, and the life of the photoconductor can be extended.

  In this embodiment, since the toner density in the developer is detected and the rotation speed of the cleaning brush is adjusted, when the toner density is high, the rotation speed of the cleaning brush is increased and the toner density is increased. When the toner is low, the rotational speed of the cleaning brush is lowered, so that the filming can be suppressed and the amount of wear of the photoconductor can be minimized, and the life of the photoconductor can be extended.

  Further, in this embodiment, since the temperature of the developer is detected and the rotation speed of the cleaning brush is adjusted, when the developer temperature is high, the rotation speed of the cleaning brush is increased and the developer temperature is increased. If it is low, the rotational speed of the cleaning brush is lowered, so that filming can be suppressed, the amount of wear of the photoconductor can be minimized, and the life of the photoconductor can be extended.

  In this embodiment, the toner adhesion amount per unit area is detected and the rotation speed of the cleaning brush is adjusted. Therefore, when the toner adhesion amount is large, the rotation speed of the cleaning brush is increased and the toner is When the amount of adhesion is small, the number of rotations of the cleaning brush is lowered. Therefore, the amount of wear of the photoconductor can be minimized while suppressing filming, and the life of the photoconductor can be extended. .

  In this embodiment, since both the toner concentration in the developer and the temperature of the developer are detected, the ease of filming is calculated from both values, and fed back to the rotation speed of the cleaning brush. In addition, the amount of wear of the photoconductor can be minimized and the life of the photoconductor can be extended.

  In this embodiment, both the toner concentration in the developer and the toner adhesion amount per unit area are detected, the ease of filming is calculated from both values, and the cleaning brush rotates. Since the number is fed back, the filming can be suppressed, the amount of wear of the photoconductor can be minimized, and the life of the photoconductor can be extended.

  In this embodiment, both the temperature of the developer and the amount of toner adhered to the photoconductor per unit area are detected, and the ease of filming is calculated from both values, and the number of rotations of the cleaning brush is calculated. Since the feedback is performed, filming can be suppressed, the amount of wear of the photoconductor can be minimized, and the life of the photoconductor can be extended.

  In this embodiment, three points of the toner concentration in the developer, the developer temperature, and the toner adhesion amount per unit area are detected, and the ease of filming is determined from the three points. Since it is calculated and fed back to the number of rotations of the cleaning brush, the amount of wear of the photoconductor can be minimized while suppressing filming, and the life of the photoconductor can be extended.

  Further, in the present embodiment, even when printing one or two image forming apparatuses on one continuous sheet, the amount of wear of the photosensitive member is reduced after suppressing filming of each of the two image forming apparatuses. It can be minimized and the life of the photoreceptor can be extended.

  Here, the embodiment described above shows an example of a preferred embodiment of the present invention, and the present invention is not limited thereto, and various modifications can be made without departing from the scope of the invention. It is.

  INDUSTRIAL APPLICABILITY The present invention can be used in an electrophotographic apparatus that records on sheet-like continuous paper by an electrophotographic system such as a laser printer, and particularly in an apparatus that cleans a drum-shaped photoconductor.

DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Charging device 3 Laser exposure device 4 Developing device 5 Developing roll 6 Transfer device 7 Static eliminating device 8 Cleaning brush 9 Cleaning device case 10 Cleaning device 11 Toner (before transfer)
12 Paper 13 Toner Concentration Detection Device 14 Thermocouple 15 Thermometer 16 Toner Adhesion Amount Detection Device 17 Unnecessary Toner (Transfer Residual Toner)
18 Developer 19 Unwinder 20 First Printer 21 Second Printer 22 Rewinder 30 Fixing Device

JP 2005-266697 A

Claims (10)

In an electrophotographic apparatus,
A drum-shaped photoreceptor having a photosensitive layer of an organic material;
A charging device for charging the photoreceptor;
An exposure device that exposes the photoreceptor to form a latent image;
A developing device for developing a latent image on the photoreceptor with toner to form a visible image;
A transfer device for transferring the visible image to paper;
A fixing device that heats and fixes the sheet onto which the visible image is transferred; and
A cleaning device for cleaning the photoconductor after transfer,
The cleaning device includes a cleaning brush, and rotates the cleaning brush in a reverse direction with respect to the photoconductor to remove transfer residual toner on the photoconductor and a function of rubbing the surface of the photoconductor. And an image forming apparatus characterized in that the rotational speed of the cleaning brush is varied in accordance with printing process conditions.   The image forming apparatus according to claim 1, wherein the cleaning device varies the number of rotations of the cleaning brush based on a toner density of a developer in the developing device.   The image forming apparatus according to claim 1, wherein the cleaning device varies the number of rotations of the cleaning brush based on a temperature of a developer in the developing device or a temperature of the photosensitive member.   The image forming apparatus according to claim 1, wherein the cleaning device varies the number of rotations of the cleaning brush based on a toner adhesion amount per unit area of the photoconductor.   2. The cleaning device according to claim 1, wherein the number of rotations of the cleaning brush is varied based on a combination of a toner density of the developer in the developing device and a temperature of the developer or a temperature of the photoconductor. The image forming apparatus described in 1.   2. The cleaning device according to claim 1, wherein the number of rotations of the cleaning brush is varied based on a combination of a toner density of the developer in the developing device and a toner adhesion amount on the photoconductor. The image forming apparatus described.   The cleaning device may vary the number of rotations of the cleaning brush based on a combination of the temperature of the developer in the developing device or the temperature of the photosensitive member, and the amount of toner adhering to the photosensitive member. The image forming apparatus according to claim 1.   The cleaning device determines the rotation speed of the cleaning brush, the toner concentration of the developer in the developing device, the temperature of the developer in the developing device or the temperature of the photosensitive member, and the adhesion of toner on the photosensitive member. The image forming apparatus according to claim 1, wherein the image forming apparatus is varied based on a combination of amounts.   The image forming apparatus according to claim 1, wherein printing is performed on a single sheet of continuous paper.   The image forming apparatus according to claim 1 is arranged in series, and after printing one sheet of continuous paper on one side of the image forming apparatus, the continuous paper is continuously printed on the other side of the image forming apparatus. An image forming system characterized by the above.

Images