JPH1049014A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain stable and sufficient cleaning performance by using a specific cleaning blade and specific toner. SOLUTION: A cleaning device 61 is provided with a cleaning blade 611. The edge part of the cleaning blade 611 comes into press-contact with a photoreceptor drum 11. This edge part abuts on the drum 11 by a counter system. In the cleaning blade 611, resilience is set >=10%, preferably >=40% and <=65%, more preferably <=60% and a projecting quantity is equal to or more than thickness and below 10 times the thickness, more preferably, 2-5 times the thickness. Further, in toner used, an average grain diameter is >=3 [μm] to <=12 [μm] and the absolute value of a charge quantity per unit weight is >=10 [μC/g] to <=50 [μC/g]. Moreover, a silicon dioxide is added to toner by >=0.05wt.%, more preferably >=0.3wt.% to <=2wt.%, as an aftertreatment agent.

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, facsimile machines,
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. Residual toner causes image defects, etc.
It 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 an image forming apparatus equipped with this type of cleaning device, for example, according to Japanese Patent Application Laid-Open No. H10-105983, the amount of protrusion of a cleaning blade is about 8 mm, its rubber hardness is 65 to 70 degrees at room temperature, and its rebound resilience is room temperature. At about 35%, the pressing force of the cleaning blade against the image carrier is further increased by 45%.
~ 55 g / cm, and the thickness of the cleaning blade is 2
It is disclosed that by setting the thickness to about 3 mm, the cleaning performance can be improved, and the occurrence of abrasion and abnormal noise of the image carrier and the cleaning blade edge can be suppressed.

According to JP-A-3-20768, a viscosity average molecular weight of 1.0 × 10 ^{4 is used} as a material of an image carrier.
Employed those containing to 5.0 × 10 ⁴ of bisphenol Z type polycarbonate resin, also assumes the counter scheme comprising a cleaning blade of a polyurethane rubber, the rubber hardness JIS A60~70 °, 38~58Kgf Young's modulus / Cm ² , thickness 1.5-2.0m
m, the protrusion amount is 9 to 13 mm, and the pressing force to the image carrier is 1.3 to 1.9 g / cm, whereby the excellent mechanical durability and coating properties of the polycarbonate resin are maintained, and the image is formed. It is disclosed that generation of abnormal noise due to friction between the carrier and the cleaning blade can be suppressed, and cleaning performance can be improved.

According to Japanese Patent Application Laid-Open No. 3-110589, it is disclosed that the cleaning performance can be improved by adding 0.02 to 1% of hydrophobic colloidal silica as a post-treatment agent to a toner. ing.

[0006]

However, each of the image forming apparatuses taught by the above-mentioned Japanese Patent Application Laid-Open Nos. 1-105983, 3-20768 and 3-110589 has several characteristic values. Although the range in which the cleaning performance can be improved is set, sufficient cleaning performance may not be obtained depending on the combination of these characteristic values. In particular, it is very difficult to obtain sufficient cleaning performance when the rebound resilience of the cleaning blade is reduced to prevent the reversal phenomenon (turning) of the cleaning blade.

Accordingly, 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 on a recording material. An image forming apparatus comprising: a cleaning device including a cleaning blade having an edge portion pressed against the image carrier for removing toner remaining on the image carrier after transfer, wherein the cleaning device is configured to perform stable and sufficient cleaning. It is an object of the present invention to provide an image forming apparatus which can obtain high performance and can perform good image formation.

[0008]

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 for removing toner remaining on the image carrier, the cleaning device including a cleaning blade having an edge portion pressed against the image carrier, wherein the cleaning blade has a rebound resilience of 10%. % Or more, more preferably 40% or more, and 65% or less,
More preferably, the protrusion amount is 60% or less, and the protrusion amount is 1 time or more and less than 10 times, more preferably 2 to 5 times, the thickness.
At least 05 wt%, more preferably at least 0.3 wt%,
Further, an image forming apparatus characterized in that 2 wt% or less is added.

The protrusion amount of the cleaning blade refers to the length of a portion protruding from the support in a state where the cleaning blade is cantilevered on the support. In the present invention, the rebound resilience of the cleaning blade is set in the above-described range because, as shown in an experiment described later, there is no practical problem in unwiped toner within this range.

Further, in the present invention, the amount of protrusion of the cleaning blade is set in the above-mentioned range because, as will be shown in an experiment to be described later, the remaining of the toner within this range does not cause any practical problem. . In the present invention, a post-treatment agent such as silicon dioxide (SiO ₂ ) is added to the toner in order to improve the fluidity of the toner. The reason why the amount of the post-treatment agent is set in the above-mentioned range is that, as will be shown in an experiment to be described later, the remaining amount of the toner and the image noise due to the post-treatment agent are practically no problem within this range.

According to the image forming apparatus of the present invention, since the rebound resilience of the cleaning blade, the amount of protrusion of the cleaning blade, and the amount of the post-treatment agent of the toner are set in the above-mentioned ranges, the results will be shown in experiments described later. Thus, good cleaning performance is obtained. This is because the rebound resilience of the cleaning blade is as large as 10% or more, so that the energy is applied to the force for cleaning the toner, and the amount of protrusion of the cleaning blade is reduced to 1 to 1 of the thickness.
By setting the magnification to 0 times, the cleaning blade stably and uniformly comes into contact with the image carrier, so that it is difficult for the toner to slip through the gap between the cleaning blade and the image carrier, and the toner post-treatment agent is applied to the toner. 0.0 for
It is considered that the addition of 5% by weight or more and 2% by weight or less causes an appropriate amount of the post-treatment agent to be accumulated at the edge of the cleaning blade.

As the image carrier, for example, a photosensitive member or a dielectric can be used. As the photoconductor, an organic photoconductor (OPC), a selenium arsenic photoconductor, a selentellur photoconductor,
Known examples such as a selenium photosensitive member, a CdS photosensitive member, and an amorphous silicon photosensitive member can be exemplified. Examples of the dielectric include those made of polycarbonate, polyester, polyamide, acetate, acryl, polyethylene, polyimide, polyurethane, and the like. In any case, the shape of the image carrier may be a drum shape, a belt shape, or the like.

The material of the cleaning blade is required to be excellent in abrasion resistance, ozone resistance, toner resistance, chemical stability (low reactivity with the image carrier), workability, and the like. As such a material, a polyurethane resin (for example, polyurethane rubber), a polytetrafluoroethylene resin, or the like can be used, but is not limited thereto.

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 state in which the cleaning blade is pressed against the image bearing member is a smaller angle (hereinafter, referred to as a “pressure contact angle”) of the angle formed between the cleaning blade and a tangent drawn on the image bearing member at the contact point between the image bearing member and the cleaning blade. ) Is about 5 to 20 °.
The pressure angle in the cleaning blade of counter type shown in FIG. 9 (A) refers to the theta ₁ of the smaller of the theta ₁ and theta _2. In the trailing type cleaning blade shown in FIG. 9B, the smaller θ ₃ out of θ ₃ and θ ₄ is indicated.

If the pressure contact angle is smaller than 5 °, the blocking force of the toner is remarkably reduced and the toner easily slips through. If it is larger than 20 °, the reversal phenomenon (turning) of the cleaning blade is liable to occur. In either case, as a result, the inside of the image forming apparatus may be stained by the charging device or the like, and streak-like or band-like noise may occur in the image.

The pressure of the cleaning blade against the image carrier is preferably about 0.5 to 5 g / mm. This is because, if it is smaller than 0.5 [g / mm], the toner stopping power is weakened, and the residual toner is easily wiped off.
If it is larger than 5 [g / mm], the frictional force between the image carrier and the cleaning blade is too large, so that the cleaning blade is likely to undulate, turn (turn up), chip at the edge portion, etc., resulting in poor cleaning and eventually poor image. Because it is easy. In addition, even if the pressing force is within the above range,
When a force is applied so that the elasticity of the cleaning blade edge is lost, the remaining toner is easily wiped off.

The average particle size of the toner used for development is
It is preferably 12 [μm] or less and 3 [μm] or more. this is,
If it is larger than 12 [μm], the image quality deteriorates and it is not practical. If it is smaller than 3 [μm], it is extremely difficult to scrape off the toner with a cleaning blade, and cleaning defects and image defects are likely to occur. is there.

Further, the absolute value of the charge amount per unit weight of the toner is preferably 10 [μC / g] or more and 50 [μC / g] or less. This is because if it is smaller than 10 [μC / g], the scattering of toner tends to increase, which causes toner fogging on the image and stains in the image forming apparatus.
If it is more than 50 [μC / g], the developability tends to deteriorate, and the density on the image is insufficient, which is not practical.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a schematic configuration diagram of an example of an image forming apparatus according to the present invention. This apparatus includes a drum-shaped photoconductor 11 as an image carrier, and a photoconductor drum 11
Charging roller 21 as a charging device and developing device 3 around
1. A transfer roller 41 is provided as a transfer device, and a charge removing needle 51 and a cleaning device 61 are provided in this order as a device for removing and separating a recording material. The photoconductor 11 is driven to rotate counterclockwise as indicated by an arrow in the figure.

The charging roller 21 is connected to a power supply capable of superimposing a negative DC voltage on an AC voltage, and can charge the surface of the photosensitive drum 11 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 photosensitive drum 11 is an organic photosensitive member (OPC)
You are using As shown in FIG. 1 (B), this organic photoreceptor has a charge generation layer 112 of a thickness of 1 μm or less made of a bisazo pigment and a binder resin, a hydrazone derivative and a polycarbonate resin formed on a surface of a cylindrical aluminum tube 111. The charge transport layer 113 having a thickness of about 23 μm is formed by laminating in this order.

The developing device 31 applies a positive electrostatic latent image created by irradiating the negatively charged photosensitive drum 11 with the negative recording image light L by the charging roller 21 to the inside of the developing device 31. The latent image can be visualized by charged powder or particles contained in the toner. In this example, the electrostatic latent image is formed by a two-component dry developing method using a non-magnetic toner powder charged positively and a magnetic carrier. The image can be visualized positively.

The cleaning device 61 includes a cleaning blade 611 made of a polyurethane resin, and the edge 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. In this image forming apparatus, the rebound resilience of the blade 611 at room temperature is 10% or more, more preferably 40% or more, and 65% or less, more preferably 60% or less. 1 or more 10
The angle is smaller than 5 times, more preferably 2 to 5 times, and the smaller angle of the angle between the photosensitive drum 11 and the blade 611 is 5 to 5 times.
20 [°], and the pressing force of the blade 611 against the drum 11 is 0.5 to 5 [g / mm]. The toner used has an average particle diameter of 12 μm or less and 3 μm or more,
The absolute value of the charge amount per unit weight is 10 [μC / g] or more and 50 [μC / g] or less. 3 wt% or more and 2 wt% or less are added.

According to this image forming apparatus, the surface of the photosensitive drum 11, which is 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. In removing the toner, the edge of the cleaning blade 611 is pressed against the surface of the photosensitive drum 11, and the residual toner is scraped off at the edge.

Hereinafter, using an image forming apparatus of the type shown in FIG. 1, the relationship between the resilience of the cleaning blade and the cleaning performance, the relationship between the amount of protrusion of the cleaning blade and the cleaning performance, and the amount of the post-treatment agent added to the toner. An experiment in which the relationship between the cleaning performance and the cleaning performance was examined will be described. The following experiments were all performed at room temperature.

FIG. 2 is a graph plotting the repulsive elasticity of the cleaning blade and the pressure at which 50% of the toner is left unwiped, and shows the relationship between the resilience of the cleaning blade and the state of occurrence of the residual toner. . The rebound resilience of the cleaning blade is variously changed by changing the type of polyurethane resin, which is a blade material, to an adipate type, a caprolactone type, or the like, or by changing a method of manufacturing the cleaning blade and its conditions. The protrusion amount of the cleaning blade is set to four times the thickness, and the pressure contact angle of the cleaning blade to the photosensitive drum 11 is set to 10 times.
[°], the average particle size of the toner was 8 μm, the absolute value of the charge amount was 20 μC / g, and the amount of the post-treatment agent added to the toner was 0.5 wt%.

The 50% unwiping start pressure is the blade pressing force at which the remaining toner starts to be 50% when the pressing force of the cleaning blade is reduced, and the 50% unwiping start pressure is used. Is 1.5 [g / mm] or less, there is no practical problem. According to this, if the rebound resilience of the cleaning blade is 10% or more, 50%
The unwiping start pressure becomes smaller than 1.5 [g / mm],
Further, if the rebound resilience is 25% or more, the change in the repulsion resilience is reduced by 50% with respect to the change in the rebound resilience, and the change in the starting pressure becomes small, indicating a stable cleaning performance. This is considered to be because when the rebound resilience is less than 10%, the restoring force of the edge of the cleaning blade is weakened, and the contact time between the cleaning blade and the image carrier is shortened. Further, here, no experiment was carried out for the rebound resilience of more than 60%, but if the rebound resilience is more than 65%, it is predicted that the reversal phenomenon (turning) of the cleaning blade is likely to occur. %Less than,
Preferably, it is desirable to be 60% or less.

FIG. 3 is a graph in which the remaining toner wiping rank is plotted with respect to the ratio of the protrusion amount to the thickness of the cleaning blade. Shows the relationship. The unwiped rank is
5 (good), 4 (almost good), 3 (no wiping is observed, but within the allowable range), 2
(Somewhat bad), 1 (bad). When the rank is lower than 3, the problem becomes practical. The rebound resilience of the cleaning blade was 65%, the pressure contact angle of the cleaning blade against the photosensitive drum 11 was 10 °, and the pressure contact force was 2 g / m 2.
m], the average particle diameter of the toner was 8 μm, the absolute value of the charge amount was 20 μC / g, and the amount of the post-processing agent added to the toner was 0.5 wt%.

According to this, when the protrusion amount of the cleaning blade is 10 times or more the thickness, the unwiped rank is lower than 3, and the unwiped toner which is a problem in practical use occurs. This is considered to be due to the fact that the bending and waving of the cleaning blade when the cleaning blade is pressed against the photosensitive drum are increased. Also,
Here, no experiment was performed when the ratio of the protrusion amount to the thickness of the cleaning blade was smaller than one time, that is, when the protrusion amount of the cleaning blade was smaller than the thickness, but in this case, the photosensitive drum was eccentric due to the eccentricity of the photosensitive drum. It is expected that the change in the angle between the cleaning blade and the cleaning blade will increase, and as a result, the amount of unwiped toner will increase. Therefore, it is desirable that the amount of protrusion of the cleaning blade be equal to or greater than its thickness.

FIG. 4 is a graph in which the rank of the remaining toner after wiping is plotted with respect to the amount of the post-processing agent added to the toner, and shows the relationship between the added amount of the post-processing agent and the occurrence state of the remaining toner after wiping. I have. The rebound resilience of the cleaning blade was 65%, the protrusion amount of the cleaning blade was four times the thickness, the pressure contact angle of the cleaning blade to the photosensitive drum 11 was 10 °, and the pressure contact force was 2 g / m.
m], the average particle size of the toner was 8 μm, and the absolute value of the charge amount was 20 μC / g.

According to this, when the amount of the post-treatment agent is 0.05 wt% or more of the toner, the unwiped rank is higher than 3, and the unwiped toner which is a practical problem does not occur. Further, if the content is 0.3 wt% or more, the remaining unwiped rank is almost close to 5, and the remaining unwiped is hardly recognized. Although no experiment was conducted here when the amount of the post-processing agent was more than 2 wt%, when the amount of the post-processing agent was more than 2 wt%, the post-processing agent adhered to the photosensitive drum, which caused image noise. Since it is expected to cause the generation, it is desirable that the amount of the post-treatment agent is 2 wt% or less.

As described above, in the present invention, only the three parameters of the rebound resilience of the cleaning blade, the protrusion amount, and the addition amount of the toner post-treatment agent, determine the optimum values for suppressing the remaining toner after wiping. For,
Compared to the case where the optimum values were obtained for many other parameters in addition to the conventional method, it is possible to improve the remaining toner wiping by adjusting the values between a small number of parameters, The tolerance of each parameter has been expanded.

In the image forming apparatus shown in FIG. 1, a charge generation 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 photoreceptor formed by laminating in this order was used, but in addition, alumite treatment was performed on a cylindrical aluminum tube, a charge generation layer composed of a phthalocyanine pigment and a binder resin, composed of a hydrazone derivative and a polycarbonate resin. An organic photoreceptor formed by laminating a charge transport layer in this order can also be used. Also, a charge generation layer, a charge transport layer and an overcoat layer are provided on a conductive substrate, a charge generation layer and a charge transport layer are reversely laminated, and an undercoat layer is provided on a conductive substrate. Can also be used. In addition to the organic photoconductor, as described above, selenium arsenic photoconductor as an image carrier,
A selenium telluride, a selenium sensitizer, a CdS sensitizer, an amorphous silicon sensitizer, or a dielectric can also be used.

In this embodiment, a charging roller is used as the charging means. In addition, a scorotron charging charger,
Known charging means such as a charging brush and a rotating charging brush can also be used. Although a transfer roller is used here as a transfer unit, a known transfer unit such as a transfer charger may be used.

Although a static elimination needle is used as the separating means here, other known separating means such as a separating charger can be used. Further, here, a cleaning blade that is pressed against the image carrier by the counter method is used as the cleaning unit, but a cleaning blade that is pressed against the image carrier by the trailing method may be used,
Further, a conveyance screw for conveying the waste toner may be provided in a waste toner bottle for storing the scraped toner. 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. Although a polyurethane resin is used as the cleaning blade material here, a polytetrafluoroethylene resin or the like may be used.

Although the developing device of the two-component dry developing system is used here, a developing device of a one-component dry developing system using only toner powder may be used. The image forming apparatus of the present invention can also include 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 are shown in FIGS. FIGS. 5 to 8 are schematic configuration diagrams of examples of the image forming apparatus according to the present invention. The image forming apparatus shown in FIG. 5 includes the same organic photoreceptor drum 11 as that shown in FIG. 1 as an image carrier, and a scorotron charger 22, a developing device 31, a transfer charger 42, a separation charger 52, and a cleaner in front thereof. A charger 7, a cleaning device 62 including a cleaning blade 621 and a conveying screw 622 which are pressed against the photosensitive drum 11 by a counter method, 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. 5, the toner remaining on the photosensitive drum 11 without being transferred onto the recording material is charged by the AC pre-cleaner charger 7 in which a DC component is biased. 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.

In this image forming apparatus, the blade 6
The rebound resilience, the protrusion amount, the pressure contact angle to the photosensitive drum 11, the pressure contact force to the drum 11, the average particle diameter of the toner, the absolute value of the charge amount per unit weight of the toner, and the amount of the post-processing agent added are shown in FIG. The range was set within the same range as that of the device No. 1. Using this image forming apparatus, the same experiment as described above was conducted while controlling the charge amount of the residual toner to 10 [μC / g] by the charger 7 before the cleaning. The cleaning performance was as shown in FIGS. Almost the same result was obtained.

The image forming apparatus shown in FIG. 6 includes a drum-shaped photosensitive member 12 as an image carrier, and a charging brush 2 around the photosensitive member.
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 photosensitive drum 12 is an organic photosensitive member (OPC)
You are using This organic photoreceptor is obtained by subjecting a cylindrical aluminum tube to alumite treatment to form a charge generation layer having a thickness of 1 μm or less made of a phthalocyanine pigment and a binder resin, and a charge transport layer having a thickness of about 20 μm made of a hydrazone derivative and a polycarbonate resin. Are laminated in this order.

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

Also in this image forming apparatus, the blade 6
31 shows the rebound resilience, the protrusion amount, the pressure contact angle to the photosensitive drum 12, the pressure contact force to the drum 12, the average particle diameter of the toner, the absolute value of the charge amount per unit weight of the toner, and the amount of the post-processing agent added. The range was set within the same range as that of the device No. 1. When an experiment similar to the above was performed using this image forming apparatus,
The cleaning performance was almost the same as that shown in FIGS. During this experiment, the cleaner brush 63
2 is controlled to control the toner charge amount to -10 μC / g and -5 μC / g.
From the experiment, it was found that the relationship between the cleaning performance and the charge amount of the toner may be determined by considering the absolute value of the charge amount of the toner.

The image forming apparatus shown in FIG. 7 has the same organic photosensitive drum 11 as that shown in FIG. 1 as an image carrier, and a rotating charging brush 24, a developing device 31, a transfer roller 41, a trailing system around the same. Cleaning blade 641 and cleaner roller 6 pressed against photoconductor drum 11 by
A cleaning device 64 including the cleaning device 42 is disposed.
The recording image light L is emitted from between the rotary charging brush 24 and the developing device 31.

In this image forming apparatus, the blade 6
The rebound resilience, the protrusion amount, the pressure contact angle to the photosensitive drum 11, the pressure contact force to the drum 11, the average particle diameter of the toner, the absolute value of the charge amount per unit weight of the toner, and the amount of the post-processing agent are shown in FIG. The range was set within the same range as that of the device No. 1. A bias power supply (not shown) is connected to the cleaner roller 642, and it is also possible to control the charge amount of the toner remaining on the photosensitive drum 11, and the same function as the pre-cleaner charger 7 shown in FIG. Also has.

When the same experiment as described above was conducted using the image forming apparatus shown in FIG. 7 while controlling the amount of charge of the residual toner by the bias power supply, the cleaning performance was as shown in FIGS. Almost the same results were obtained.
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. 8 includes a drum-shaped dielectric 13 as an image carrier, and a recording electrode 9 around the dielectric 13.
1. Developing device 31, transfer roller 41, cleaning blade 6 pressed against dielectric drum 13 by 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.

In this image forming apparatus, the blade 6
The rebound resilience, the protrusion amount, the pressure contact angle to the dielectric drum 13, the pressure contact force to the drum 13, the average particle diameter of the toner, the absolute value of the charge amount per unit weight of the toner, and the amount of the post-treatment agent are shown in FIG. The range was set within the same range as that of the device No. 1. When an experiment similar to the above was performed using the image forming apparatus shown in FIG. 8, the cleaning performance was almost the same as that shown in FIGS. 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.

[0050]

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 to a recording material. An image forming apparatus including a cleaning device including a cleaning blade having an edge portion pressed against the image carrier for removing toner remaining on the image carrier after transfer, and Thus, it is possible to provide an image forming apparatus which can achieve good cleaning performance and can perform good image formation accordingly.

[Brief description of the drawings]

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

FIG. 2 shows the rebound resilience of a cleaning blade and toner 5
It is a graph which shows the relationship with 0% of unwiping start pressure.

FIG. 3 is a graph showing the relationship between the ratio of the protrusion amount to the thickness of the cleaning blade and the remaining toner wiping rank.

FIG. 4 is a graph showing the relationship between the amount of a post-treatment agent added to a toner and the remaining toner wiping rank.

FIG. 5 is a schematic configuration diagram of another example of the image forming apparatus according to the present invention.

FIG. 6 is a schematic configuration diagram of still another example of the image forming apparatus according to the present invention.

FIG. 7 is a schematic configuration diagram of still another example of the image forming apparatus according to the present invention.

FIG. 8 is a schematic configuration diagram of still another example of the image forming apparatus according to the present invention.

9A and 9B are diagrams for explaining a method in which a cleaning blade is brought into contact with an image bearing member. FIG. 9A is a diagram for explaining a counter system, and FIG. 9B is a diagram for explaining a trailing system. 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 θ ₁ , θ ₂ , θ ₃ , θ ₄ Angle between cleaning blade and photosensitive drum (image carrier)

 ──────────────────────────────────────────────────の Continuing on the front page (72) Shingo Hirota 2-3-13-Azuchicho, Chuo-ku, Osaka-shi Inside Osaka International Building Minolta Co., Ltd. (72) Futa Okazaki 2-3-3 Azuchicho, Chuo-ku, Osaka-shi No. 13 Osaka International Building Minolta Co., Ltd.

Claims (2)

[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 for removing toner remaining on the image carrier, the cleaning device including a cleaning blade having an edge portion pressed against the image carrier, wherein the cleaning blade has a rebound resilience of 10 % Or more 6
5% or less and protrusion amount is 1 time or more of thickness 1
The image forming apparatus according to claim 1, wherein the toner to be developed is less than 0 times, and the post-processing agent is added in an amount of 0.05 wt% or more and 2 wt% or less. 2. The toner image has an average particle size of 12 [μm] or less and 3 [μm] or more, and an absolute value of a charge amount is 10 [μC / g].
The cleaning blade is formed of a toner of 50 μC / g or less, and the smaller angle between the tangent drawn on the image carrier at the contact point between the image carrier and the cleaning blade and the cleaning blade is 5 to 20. [°], the pressing force of the cleaning blade against the image carrier is 0.5 to 5
2. The image forming apparatus according to claim 1, wherein the value is [g / mm].