JPH09281865A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain the chipping of the edge part of a cleaning blade and to form an excellent image by specifying the physical characteristic of the cleaning blade. SOLUTION: This device is provided with a drum-like photoreceptor 11 being an image carrier. Then, an electrifying roller 21 functioning as an electrifying device, a developing device 31, a transfer roller 41 functioning as a transfer device, a discharging needle 51 functioning as a device for discharging and separating the recording material and a cleaning device 61 are arranged around the drum 11. The cleaning device 61 is provided with the cleaning blade 611 made of polyurethane resin, and the edge part of the blade 611 is press-contacted with the drum 11. The hardness of the blade 611 is set to 60-80 deg., desirably, 60-75 deg., the Young's modulus of the blade 611 is set to 30-120[kg/cm<2> ], desirably, 30-80[kg/cm<2> ], and the tensile strength of the blade 611 is 100-600[kg/cm<2> ], desirably, 100-450[kg/cm<2> ].

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 such as an electrophotographic copying machine, a facsimile, and a printer, and more particularly, to a method for transferring a toner image formed on an image carrier such as a photoreceptor or a dielectric to a recording material. The present invention relates to an image forming apparatus including a cleaning device including a cleaning blade pressed against the image carrier for removing toner remaining on the image carrier after transfer.

[0002]

2. Description of the Related Art Electrophotographic copying machines, facsimiles,
2. Description of the Related Art In an image forming apparatus such as a printer, an electrostatic latent image is formed on an image carrier such as a photoreceptor or a dielectric, and the electrostatic latent image is developed with a toner as a developer. The image is transferred to the recording material. At this time, most of the toner is transferred to the recording material, but some of the toner remains on the image carrier. If the residual toner is not removed, a defect such as an image defect occurs, and thus the residual toner is removed by the cleaning device.

[0003] Various types of cleaning devices have been proposed. For example, in a cleaning device using a cleaning blade, an edge portion of the cleaning blade is pressed against an image carrier, and an image is formed by the edge portion. The residual toner on the carrier is scraped off. In the case of this type of cleaning device, when the edge portion of the cleaning blade is used in pressure contact with the image carrier, a frictional force with the image carrier is applied to the edge portion as the surface of the image carrier moves. An inversion phenomenon occurs in which the edge portion is gradually dragged in the moving direction of the surface of the image carrier and deformed. This reversal phenomenon shortens the life of the cleaning blade, and also causes poor cleaning and, consequently, poor image quality.

In order to prevent the reversal phenomenon, for example, in the cleaning device taught in Japanese Patent Laid-Open No. 1-21489, the cleaning blade has a roughness of 1 μm or more and 0.5 times or less of the average particle diameter of the toner. It is proposed to provide the unevenness. In the cleaning device taught by Japanese Utility Model Laid-Open No. 2-55270, it is proposed that the cleaning blade has a surface roughness of 3 to 7 [μmRz]. It teaches that this device can prevent chattering and comets in addition to the reversal phenomenon.

[0005]

However, when the edge portion of the cleaning blade is used in pressure contact with the image bearing member, the edge portion may be chipped, and the chipping of the edge portion causes poor cleaning. As a result, it causes a defective image. The chipping of the edge portion is likely to occur due to the physical characteristics of the cleaning blade, the characteristics of the toner, and the like.
No mention is made of Japanese Patent No. 489 or Japanese Utility Model Laid-Open No. 55270/1990.

Therefore, the present invention is an image forming apparatus for forming an electrostatic latent image on an image carrier, developing the latent image with toner to form a visible toner image, and transferring and fixing the toner image onto a recording material. In an image forming apparatus including a cleaning device including a cleaning blade for removing the toner remaining on the image bearing member after transfer, the edge portion is pressed against the image bearing member at a predetermined pressure contact angle and pressure contact force. Therefore, it is an object of the present invention to provide an image forming apparatus capable of sufficiently suppressing chipping of the edge portion of the cleaning blade and performing good image formation.

[0007]

According to the present invention, an electrostatic latent image is formed on an image carrier, and the latent image is developed with toner to form a visible toner image. Is an image forming apparatus for transferring and fixing a recording material onto a recording material.
An image forming apparatus, comprising: a cleaning device including a cleaning blade for removing a toner remaining on the image bearing member, the edge portion of which is pressed against the image bearing member at a predetermined pressure contact angle and force. The hardness of the cleaning blade is 60 to 80 degrees, preferably 60 to 75 degrees, and the Young's modulus of the cleaning blade is 30 to 120.
[Kg / cm ² ], preferably 30 to 80 [kg / cm 2
² ] and the tensile strength of the cleaning blade is 10
0 to 600 [kg / cm ² ], preferably 100 to 45
Provided is an image forming apparatus characterized by being 0 [kg / cm ² ].

The hardness of the cleaning blade is measured according to JIS-K6301 according to JIS-A.
It is measured using a mold hardness tester. Examples of the image carrier include a photoconductor and a dielectric. As the photoreceptor, organic photoreceptor, selenium arsenide photoreceptor,
Known materials such as a selenium tellurium photoconductor, a selenium photoconductor, a CdS photoconductor, and an amorphous silicon photoconductor can be exemplified. Further, examples of the dielectric material include polycarbonate, polyester, polyamide, acetate, acrylic, polyethylene, polyimide, polyurethane and the like. In any case, the shape of the image carrier may be a drum shape or a belt shape.

The toner has an average particle size of 3 to 15 [μ
m] and the absolute value of the charge amount (particularly the charge amount of the residual toner) is preferably 5 to 50 [μC / g]. This is a characteristic of a commonly used toner. When the average particle diameter of the toner is smaller than 3 [μm], it is extremely difficult to scrape off the toner with a cleaning blade, and cleaning failure and image failure occur. Cheap.
Further, when the average particle size is larger than 15 [μm], the image quality becomes poor and it is not practical. On the other hand, when the absolute value of the charge amount is less than 5 [μC / g], the toner is often scattered, which causes toner fogging on the image and stains in the image forming apparatus. Also, the absolute value of the charge amount is 50 [μC / g]
When it is larger than the above range, the developability is deteriorated and the image density is insufficient, which is not practical.

Examples of the material of the cleaning blade include polyurethane resin and tetrafluoroethylene resin.
This is not the case. . As a method of pressing the cleaning blade against the image carrier, any of a counter method and a trailing method can be adopted. The predetermined press contact angle of the cleaning blade is such that the tangent line of the surface of the image carrier and the surface of the cleaning blade on the downstream side in the moving direction of the surface of the image carrier at a position where the cleaning blade contacts the image carrier. It refers to the angle to make, this press contact angle is 5 to 20
It is preferably in the range of [°]. The pressure contact angle is 5
When it is smaller than [°], the blocking force of the toner is significantly reduced, and the toner easily slips through. Therefore, in the charging device or the like, the inside of the image forming apparatus may become dirty, or streak-shaped or band-shaped noise may occur in the image. When the pressure contact angle is larger than 20 °, the cleaning blade is likely to be turned over. Therefore, in the charging device or the like, the inside of the image forming apparatus may become dirty, or streak-shaped or band-shaped noise may occur in the image.

The predetermined pressure contact force of the cleaning blade is preferably in the range of 0.5 to 5 [g / mm]. When the pressure contact force is less than 0.5 [g / mm], it is difficult to prevent the residual toner, and cleaning failure and image failure are likely to occur. Further, the pressure contact force is 5 [g /
[mm], the frictional force between the image bearing member and the cleaning blade is too large, and the cleaning blade is likely to wavy or turn over (turn over), and the edge portion is chipped, resulting in poor cleaning and eventually defective images.

As described above, the hardness of the cleaning blade is in the range of 60 to 80 degrees, preferably 60 to 75 degrees. The Young's modulus of the cleaning blade is in the range of 30 to 120 [kg / cm ² ], preferably 30 to 80 [kg / cm ² ]. The tensile strength of the cleaning blade is 10
0 to 600 [kg / cm ² ], preferably 100 to 45
It is desirable to be in the range of 0 [kg / cm ² ]. The hardness, Young's modulus, and tensile strength values of the cleaning blade are based on the findings of experiments to be described later that it is possible to suppress chipping of the cleaning blade when it is within the above range.

In the above-mentioned image forming apparatus of the present invention, it is also considered that the permanent elongation of the cleaning blade is 5% or less, preferably 2% or less. The value of the permanent elongation of the cleaning blade is also based on the finding that it is possible to suppress chipping of the cleaning blade when it is within the above range by an experiment described later.

According to the image forming apparatus of the present invention, the cleaning blade has a hardness of 60 to 80 degrees, a Young's modulus of 30 to 120 [kg / cm ² ] and a tensile strength of 100.
Since each of them is as small as ~ 600 [kg / cm ² ], it has a tenacity against a relatively large deformation of the edge portion pressed against the image carrier, and the edge portion is suppressed from being chipped, so that good image formation is achieved. It can be performed. Further, when the permanent elongation of the cleaning blade is 5% or less, the intermolecular bonding force of the blade material becomes strong,
As a result, chipping of the edge portion can be further suppressed, and better image formation can be performed.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention. This device is
A drum-shaped photoconductor 11 serving as an image carrier, which is rotated counterclockwise in the figure, is provided. A charging roller 21 as a charging device, a developing device 31, a transfer roller 41 as a transfer device, and a recording device are provided around the photoconductor drum 11. A static elimination needle 51 and a cleaning device 61 are arranged in this order as a material static elimination and separation device.

A power source capable of superimposing a negative DC voltage on an AC voltage is connected to the charging roller 21, and the surface of the photosensitive drum 11 can be charged to a negative potential. The recording image light L is emitted from between the charging roller 21 and the developing device 31 to a region on the surface of the photoconductor 11 that is uniformly charged by the charging roller 21. In the case where the image forming apparatus is an analog copying machine, the recording image light L is the light reflected from the original image guided by an optical scanning system including an illumination lamp, a reflection mirror, an imaging lens, and the like. When the image forming apparatus is a digital copying machine, the original image read by the optical scanning system is photoelectrically converted by an image sensor such as a CCD, and is temporarily stored in a storage unit such as a memory, and the data stored in the storage unit is temporarily stored. Irradiation is performed by exposure means including a semiconductor laser or the like based on. When the image forming apparatus is a printer or a facsimile, the printer,
Irradiation is performed by exposure means including a semiconductor laser or the like based on image data input from a host device such as a computer connected to a facsimile.

The photoconductor drum 1 uses an organic photoconductor (OPC). This organic photoreceptor comprises a cylindrical aluminum tube 111, a charge generation layer 112 made of a bisazo pigment and a binder resin and having a thickness of 1 [μm] or less, and a thickness of about 23 [μm made of a hydrazone derivative and a polycarbonate resin. ] The charge transport layer 113 is formed in this order by stacking (see FIG. 1B).

The developing device 31 accommodates in the developing device 31 an electrostatic latent image formed by irradiating the photosensitive drum 11 negatively charged by the charging roller 21 with the positive recording image light L. In this example, the electrostatic latent image can be visualized by a charged two-component dry developing method using a non-magnetic toner powder positively charged and a magnetic carrier. It can be visualized. The developing device is not limited to the two-component dry developing system described above, but may be a one-component dry developing system using only toner powder, or a wet developing process using an ink such as dissolving pigment particles in an isoper or the like. It is also possible to employ a developing device based on a system or the like.

The cleaning device 61 is provided with a cleaning blade 611 made of polyurethane resin, and an edge portion of the blade 611 is pressed against the photosensitive drum 11. The cleaning blade 611 is in contact with the photosensitive drum 11 at the edge portion by a counter method. The counter method is a method in which the cleaning blade is brought into contact with the image carrier by the method shown in FIG. 13 (A), and there is also a so-called trailing method as shown in FIG. 13 (B). In any of the methods, as shown in FIGS. 13A and 13B, the pressure contact angle θ of the cleaning blade is set so that the tangent line of the surface of the image carrier and the cleaning blade at the position where the image carrier contacts the cleaning blade. The angle formed by the surface on the downstream side in the moving direction of the image carrier surface.

According to this image forming apparatus, the surface of the photosensitive drum 11 driven to rotate counterclockwise in FIG. 1A is uniformly charged to a negative potential by the charging roller 21.
By irradiating the charged photosensitive drum 11 with the recording image light L, an electrostatic latent image corresponding to the recording image light L is formed.
The electrostatic latent image is converted into a toner image by the developing device 31 and is transferred onto a recording material fed by a feeding unit (not shown).
Is transferred. The recording material to which the toner image has been transferred is separated from the photosensitive drum 11 by the charge elimination needle 51, and then the toner image is fixed by a fixing unit (not shown), and is discharged out of the apparatus.

On the other hand, the toner remaining on the photosensitive drum 11 without being transferred to the recording material is removed by the cleaning device 61 so as not to adversely affect the next image forming process. Note that a pattern or the like created on the photosensitive drum 11 for image adjustment is not transferred to the recording material and is removed by the cleaning device 61 as it is. When removing the toner, the cleaning blade 611 has its edge portion pressed against the surface of the photoconductor drum 11 to scrape off the residual toner at the edge portion.

Hereinafter, using the image forming apparatus of the type shown in FIG. 1, the physical characteristics of the cleaning blade (hardness, Young's modulus, tensile strength, permanent elongation) and the charge amount of the residual toner (absolute value: 5, 10). , 15 [μC / g]), and an experiment at room temperature conducted to investigate the occurrence of chipping at the edge portion of the cleaning blade pressed against the photosensitive drum. In the following experimental results, the cleaning blade was pressed against the photosensitive drum by the counter method (see FIG. 13A), and the pressing angle θ (FIG. 13) was used.
(See (A)) is an experiment conducted at 10 [°] and a pressure contact force of 2 [g / mm]. Further, in any of FIGS. 2 to 8 showing the experimental results, in the figure, “◯” indicates that the edge part was not chipped, “Δ” indicates that a minute chip was generated, and “ “X” indicates that chipping occurred.

2 to 4 show the results of an experiment in which the occurrence of chipping at the edge portion was investigated when the hardness and Young's modulus of the cleaning blade were changed.
4 is the absolute value of the charge amount of the toner is 5, 10, 15
It is an experimental result at [μC / g]. Further, FIGS. 5 to 7 show the experimental results for examining the occurrence of chipping at the edge portion when the Young's modulus and the tensile strength of the cleaning blade were changed, and FIGS. It is an experimental result when the absolute value of the charge amount is 5, 10, 15 [μC / g].

From the experimental results shown in FIGS. 2 to 7, it can be seen that, with respect to hardness, Young's modulus and tensile strength, as the values increase, chipping easily occurs at the edges. hardness,
There is a relatively strong positive correlation between the physical properties of Young's modulus and tensile strength, and it is considered that all of these physical properties represent the hardness of the material. Therefore, if the values of these physical properties become large, As a result, it becomes hard, but on the other hand, it becomes brittle. Therefore, it is considered that when a cleaning blade having a large value of these physical properties is used, chipping is likely to occur at the edge portion. Further, if these physical properties become too small, it is considered that the stiffness becomes weak and the ability to scrape off the toner decreases.

Further, it can be seen that the larger the absolute value of the charge amount of the toner, the less likely the chipping of the edge portion will occur. This is because the larger the absolute value of the toner charge amount, the stronger the adhesion to the photosensitive drum, and the larger the amount of residual toner,
Further, it is considered that the residual toner acts as a buffer between the cleaning blade and the photoconductor drum, so that the absolute value of the toner charge amount is large, and the residual toner adheres to the photoconductor drum to some extent to enhance the buffering action. To be Further, in FIGS. 4 and 7 in which the absolute value of the toner charge amount is 15 [μC / g], almost no edge portion is chipped. It is considered that chipping is unlikely to occur.

As described above, the hardness of the cleaning blade at room temperature is 60 to 80 degrees, and the Young's modulus is 30 to 120.
[Kg / cm ² ] and tensile strength of 100 to 600
When [kg / cm ² ] is set, chipping of the edge portion pressed against the photosensitive drum can be sufficiently suppressed, and thus good image formation can be achieved. The physical characteristics of the cleaning blade are 60 to 7 in terms of hardness.
Within the range of 5 degrees, chipping of the edge part can be further suppressed, and regarding Young's modulus, the chipping of the edge part can be suppressed more within the range of 30 to 80 [kg / cm ² ] and the tensile strength can be 100. When it is in the range of 450 [kg / cm ² ], chipping of the edge portion can be further suppressed, and good image formation can be achieved for each.

Next, FIG. 8 shows the experimental results of examining the occurrence of chipping at the edge portion when the permanent elongation of the cleaning blade and the toner charge amount are changed. From the experimental results shown in FIG. 8, it can be seen that the larger the permanent elongation, the more likely the edge portion will be chipped. It is considered that this is because the intermolecular bonding force of the material forming the cleaning blade becomes smaller as the permanent elongation becomes larger. Therefore, it is considered that the cleaning blade having the larger permanent elongation is more likely to cause edge chipping.

Further, it can be seen that the larger the absolute value of the charge amount of the toner, the less likely the chipping of the edge portion will occur. This is considered for the same reason as described above. As described above, when the permanent elongation of the cleaning blade is set to 5% or less, the cleaning blade can be sufficiently prevented from being chipped, so that good image formation can be performed. When the permanent elongation of the cleaning blade is 2% or less, chipping of the cleaning blade can be further suppressed, and thus better image formation can be performed.

In the image forming apparatus shown in FIG. 1, a charge generating layer composed of a bisazo pigment and a binder resin and a charge transport layer composed of a hydrazone derivative and a polycarbonate resin are formed on the surface of a cylindrical aluminum tube as an image carrier. An organic photoconductor formed by stacking in this order was used. In addition to this, a cylindrical aluminum tube was subjected to alumite treatment, and a charge generation layer consisting of a phthalocyanine pigment and a binder resin, a hydrazone derivative and a polycarbonate resin were used. It is also possible to use an organic photoreceptor formed by stacking charge transport layers in this order. Examples of the organic photoreceptor include those having a charge generation layer, a charge transport layer and an overcoat layer provided on a conductive substrate, those having a charge generation layer and a charge transport layer reversely laminated, and those having a conductive substrate. And an undercoat layer may be used.
In addition to organic photoconductors, as described above, selenium arsenic photoconductor, selenium telluride photoconductor, selenium photoconductor,
It is also possible to use a CdS photoconductor, an amorphous silicon photoconductor or a dielectric. Further, although the charging roller is used as the charging means, other known charging means such as a scorotron charging charger, a charging brush, and a rotary charging brush can be used. Further, although the transfer roller is used as the transfer means, other known transfer means such as a transfer charger may be used. In addition, although the static elimination needle is used as the separation means, a known separation means such as a separation charger may be used. In addition, although a cleaning blade that is pressed against the image carrier by a counter method is used as the cleaning means, a cleaning blade that is pressed against the image carrier by a trailing method may be used. A conveyance screw for conveying the waste toner may be provided in the waste toner bottle. In addition to using a cleaning blade, paper dust and foreign matter on the image carrier can be removed, residual toner on the image carrier can be scraped off, and toner and the like can be applied to the image carrier with less toner. It is also possible to provide a cleaner brush and a cleaner roller that can control the amount of charge of the residual toner by supplying or connecting a bias power supply. Polyurethane resin was used as the cleaning blade material, but tetrafluoroethylene resin or the like can also be used. Further, the image forming apparatus of the present invention may be provided with a pre-cleaner charger for controlling the surface potential of the image carrier before cleaning and the charge amount of the toner, and a static eliminator such as an optical static eliminator.

As described above, the image forming apparatus of the present invention can take various modes depending on the combination of the image carrier and the like, and examples thereof are shown in FIGS. 9 to 12 are schematic configuration diagrams of the image forming apparatus according to the present invention. The image forming apparatus shown in FIG. 9 includes the same organic photosensitive drum 11 as that shown in FIG. 1 as an image bearing member, and around it, a scorotron charging charger 22, a developing device 31, a transfer charger 42, a separation charger 52, a cleaner front. A charger 7, a cleaning blade 62 that is brought into pressure contact with the photosensitive drum 11 by a counter method, a cleaning device 62 that includes a conveying screw 622, and an optical neutralization device 8 are arranged. The recording image light L is irradiated positively from between the charging charger 22 and the developing device 31.

According to the image forming apparatus shown in FIG. 9, the toner remaining on the photosensitive drum 11 without being transferred onto the recording material is charged by the pre-cleaning charger 7 of the AC in which the DC component is biased. After is controlled
It is removed by the cleaning device 62. Further, a toner pattern or the like created on the photoconductor drum 11 for image adjustment is similarly removed by the cleaning device 62. When an experiment similar to that described above was performed using this image forming apparatus, the occurrence of chipping of the cleaning blade 621 was substantially the same as that shown in FIGS.

The image forming apparatus shown in FIG. 10 includes a drum-shaped photoconductor 12 as an image carrier, and a charging brush 2 around the drum-shaped photoconductor 12.
3. developing device 32, transfer roller 41, cleaning blade 6 pressed against photosensitive drum 11 in a counter system
A cleaning device 63 including a cleaning brush 31 and a cleaner brush 632 is disposed. The recording image light L is applied to the charging brush 2
Irradiation is performed from between the developing device 3 and the developing device 32.

The photoconductor drum 12 is an organic photoconductor (OPC).
Are using. In this organic photoreceptor, a cylindrical aluminum tube is subjected to alumite treatment, and a charge generation layer having a thickness of 1 [μm] or less made of a phthalocyanine-based pigment and a binder resin and a thickness of about 20 [made of a hydrazone derivative and a polycarbonate resin]. [μm] of the charge transport layer are laminated in this order.

The developing device 32 is of a two-component dry developing type, and the negative recording image light L is applied to the photosensitive drum 12 charged in the negative polarity by the non-magnetic toner powder charged in the negative polarity and the magnetic carrier. A toner image corresponding to the recorded image is formed on the photosensitive drum 12 in accordance with the electrostatic latent image created by irradiation. The developing device 32 has a polarity opposite to that of the developing device 31 shown in FIGS. Also,
A bias power source (not shown) is connected to the cleaner brush 632, and the charge amount of the toner remaining on the photoconductor drum 12 can be controlled. The same function as that of the pre-cleaner charger 7 shown in FIG. It also has a combination.

When an experiment similar to that described above was conducted using this image forming apparatus, the occurrence of chipping of the cleaning blade 631 was substantially the same as that shown in FIGS. In this experiment, a bias power source (not shown) connected to the cleaner brush 632 is controlled to change the toner charge amount to −10 [μC / g] and −5 [μC / g].
As a result of performing the experiment in [g], it was found that the relationship between the occurrence of chipping of the cleaning blade and the charge amount of the toner can be obtained by considering the absolute value of the charge amount of the toner.

The image forming apparatus shown in FIG. 11 is equipped with the same organic photosensitive drum 11 as that shown in FIG. 1 as an image carrier, around which a rotary charging brush 24, a developing device 31, a transfer roller 41, and a trailing system. A cleaning device 64 including a cleaning blade 641 and a cleaner roller 642 that are pressed against the photosensitive drum 11 is arranged. The recording image light L is transmitted to the rotary charging brush 24 and the developing device 31.
Irradiated from between.

A bias power source (not shown) is connected to the cleaner roller 642, and the charge amount of the toner remaining on the photosensitive drum 11 can be controlled.
Has the same function as the pre-cleaner charger 7 shown in FIG. An experiment similar to the above was conducted using the image forming apparatus shown in FIG. 11 while controlling the charge amount of the residual toner by the bias power source.
With respect to the occurrence status of chipping of No. 41, substantially the same results as those shown in FIGS. As a result, it was found that the effect of the present invention can be obtained by applying the cleaning blade to the image carrier regardless of the counter method or the trailing method.

The image forming apparatus shown in FIG. 12 is provided with a drum-shaped dielectric 13 as an image carrier, and a recording electrode 9 is provided around the dielectric 13.
1, a developing device 31, a transfer roller 41, and a cleaning blade 6 pressed against the photosensitive drum 11 by a counter method.
A cleaning device 65 provided with 51 and a static elimination brush 92 are arranged. The dielectric drum 13 is formed by applying a dielectric resin on a cylindrical aluminum tube. In this image forming apparatus, an electrostatic latent image is formed on the dielectric drum 13 by the recording electrode 91.

When an experiment similar to the above was conducted using the image forming apparatus shown in FIG. 12, the cleaning blade 6
With respect to the occurrence status of chipping of 51, the same results as those shown in FIGS. 2 to 8 were obtained. As a result, it was found that the effects of the present invention can be obtained regardless of whether the image carrier is a photoconductor or a dielectric.

[0040]

According to the present invention, an image forming apparatus for forming an electrostatic latent image on an image carrier, developing the latent image with toner to form a visible toner image, and transferring and fixing the toner image onto a recording material. And image formation including a cleaning device including a cleaning blade for removing the toner remaining on the image bearing member after transfer, the edge portion being pressed against the image bearing member at a predetermined pressure contact angle and pressure contact force. The device, by sufficiently suppressing the chipping of the edge of the cleaning blade,
It is possible to provide an image forming apparatus capable of forming an image as good as that.

[Brief description of drawings]

FIG. 1A is a schematic configuration diagram of an image forming apparatus according to an embodiment of the present invention, and FIG. 1B is a sectional view of a photosensitive drum.

FIG. 2 shows the results of an experiment in which the occurrence of chipping at the edge was examined by changing the hardness and Young's modulus of the cleaning blade when the absolute value of the charge amount of the toner was 5 [μC / g]. is there.

FIG. 3 shows an experimental result in which the occurrence of chipping at the edge portion was investigated by changing the hardness and Young's modulus of the cleaning blade when the absolute value of the toner charge amount was 10 [μC / g]. is there.

FIG. 4 shows the results of an experiment in which the occurrence of chipping at the edge portion was investigated by changing the hardness and Young's modulus of the cleaning blade when the absolute value of the charge amount of the toner was 15 [μC / g]. is there.

FIG. 5 shows an experimental result of investigating the occurrence of chipping at the edge portion by changing the Young's modulus and the tensile strength of the cleaning blade when the absolute value of the charge amount of the toner is 5 [μC / g]. Is.

FIG. 6 shows the experimental results of examining the occurrence state of chipping of the edge portion by changing the Young's modulus and the tensile strength of the cleaning blade when the absolute value of the charge amount of the toner is 10 [μC / g]. Is.

FIG. 7 shows the experimental results of examining the occurrence of chipping at the edge portion by changing the Young's modulus and tensile strength of the cleaning blade when the absolute value of the charge amount of the toner is 15 [μC / g]. Is.

FIG. 8 shows the results of an experiment in which the occurrence of chipping at the edge portion was investigated when the permanent elongation of the cleaning blade and the amount of charge on the toner were changed.

FIG. 9 is a schematic configuration diagram of an image forming apparatus according to another embodiment of the present invention.

FIG. 10 is a schematic configuration diagram of an image forming apparatus according to still another embodiment of the present invention.

FIG. 11 is a schematic configuration diagram of an image forming apparatus according to still another embodiment of the present invention.

FIG. 12 is a schematic configuration diagram of an image forming apparatus according to still another embodiment of the present invention.

13A and 13B are diagrams for explaining a method of bringing a cleaning blade into contact with an image carrier, FIG. 13A is a counter method and FIG. 13B is a trailing method. is there.

[Brief description of reference numerals]

11, 12 Photosensitive drum (image carrier) 13 Dielectric drum (image carrier) 21 Charging roller 22 Scorotron charger 23 Charging brush 24 Rotary charging brush 31, 32 Developing device 41 Transfer roller 42 Transfer charger 51 Static elimination needle 52 Separation Charger 61, 62, 63, 64, 65 Cleaning device 611, 621, 631, 641, 651 Cleaning blade 622 Waste toner transport screw 632 Cleaner brush 642 Cleaner roller 7 Charger before cleaner 8 Light neutralizer 91 Recording electrode 92 Static neutralizing brush L Recording Image light

Claims (3)

[Claims] An image forming apparatus for forming an electrostatic latent image on an image carrier, developing the latent image with toner to form a visible toner image, and transferring and fixing the toner image on a recording material. ,
An image forming apparatus, comprising: a cleaning device including a cleaning blade, an edge portion of which is brought into pressure contact with the image carrier at a predetermined pressure contact angle and pressure contact force, for removing toner remaining on the image carrier, The cleaning blade has a hardness of 60 to 80 degrees, a Young's modulus of 30 to 120 [kg / cm ² ] and a tensile strength of 1.
An image forming apparatus characterized by having an image density of 0.00 to 600 [kg / cm ² ]. 2. The image forming apparatus according to claim 1, wherein the permanent elongation of the cleaning blade is 5% or less. 3. The toner image has an average particle diameter of 3 to 15 [μm].
Further, the cleaning blade is formed of a toner having an absolute charge amount of 5 to 50 [μC / g], and the pressure contact angle of the cleaning blade is a tangent line of the surface of the image carrier at the position where the edge portion of the blade and the image carrier are in contact with each other. And the angle between the surface of the blade on the downstream side in the moving direction of the surface of the image carrier and 5 to 2
0 [°] and the pressing force of the blade is 0.5 to 5 [g]
/ Mm]. The image forming apparatus according to claim 1 or 2.