JP2003043889A - Electrostatic image developing toner, cleaning device, method and device for forming image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaning device capable of effectively removing toner left after transfer performed on an image carrier. SOLUTION: The cleaning device is used for an image forming method for forming an electrostatic image on the image carrier, developing the image with toner having a ratio of a volume averaged grain size to a number averaged grain size (volume averaged grain size/number averaged grain size) of 1.01 to 1.25, and also, having an average circularity of 0.950 to 0.995, and transferring the toner image to a transfer material directly or through an intermediate transfer body, and then, cleaning the toner left on the image carrier after the toner image is transferred. A voltage is applied on a cleaning means so as to form an electrical field on the image carrier between the image carrier and the cleaning means, and then, the toner left after transfer on the image carrier is attracted by the cleaning means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method and apparatus, and an electrostatic charge image developing toner used therein.
Regarding the cleaning device.

[0002]

2. Description of the Related Art In recent years, there has been a strong demand for image quality of image forming apparatuses using electrophotography. In order to improve the image quality, it has been found that reducing the particle size and spheroidizing the toner are effective means. Further, it has been found that in a color image (including a full-color image), the gloss of the image greatly contributes to the image quality.

As a toner satisfying these requirements, there is a toner by a polymerization method (toner particles in which a colorant, a charge control agent and the like are included in a polymer particle in a step of polymerizing a polymer from a monomer). By the polymerization method, it is possible to efficiently manufacture a small particle size toner having a narrow particle size distribution and a spherical toner. Furthermore, by using a dry spherical toner containing wax, it has excellent hot offset resistance, and especially when used in full-color copying machines, it does not require oil in the fixing unit and has color reproducibility, transparency and gloss. An image with excellent stability can be obtained.

However, it is known that the spherical toner having a small particle diameter obtained by the polymerization method has some problems. The most important problem is that it is difficult to completely remove the transfer residual toner on the surface of the image bearing member by a cleaning means, and cleaning failure occurs. In particular, in the blade cleaning method, the toner comes close to the closest packed state between the contact portion of the image bearing member and the cleaning blade during cleaning, and the first layer toner and the next layer having strong adhesion to the image bearing member. The toner slips with the toner of the second layer, and the toner of the first layer remains on the image carrier as a cleaning failure.

In order to solve such problems, the following a and b have been proposed. a. In a method of cleaning an image forming apparatus in which a cleaning blade is pressed against the surface of an image carrier to remove residual toner on the surface of the image carrier, a conductive member is used for the cleaning blade, and an AC bias voltage and A cleaning method characterized by applying a DC bias voltage having the same polarity as the electrified charge to remove the residual toner on the surface of the image bearing member (JP-A-5-265360).

B. In a cleaning device of an electrophotographic apparatus in which residual toner on a photoconductor after transfer is scraped off by a cleaning blade to clean the surface of the photoconductor, the cleaning blade is made of a conductive material and is grounded. Alternatively, a DC voltage having a polarity opposite to that of the residual toner is applied. Alternatively, a DC voltage having the same polarity as the residual toner is applied. Alternatively, an AC voltage is applied to it (Japanese Patent Laid-Open No. 7-210).
No. 053).

However, in all of these, a cleaning blade is brought into contact with the image carrier to scrape off the residual toner after transfer, so that a sharp-melting polyester-based toner binder having a lower melt viscosity than the conventional toner is used. In the case of the toner, the wax existing near the surface inside the toner resin exudes to the surface by the pressure of the cleaning plate and is rubbed against the image carrier to be attached, so-called wax filming occurs.

FIG. 21 shows the results of measuring the friction coefficient of the photoconductor according to the operating time of the copying machine when the wax exudes from the wax-containing toner and the toner containing no wax is used. When wax filming occurs on the image bearing member in this way, the friction coefficient of the image bearing member is considerably lowered. When the friction coefficient of the image carrier decreases, the adhesion between the image carrier and the toner decreases. Therefore, before the nip between the transfer material such as paper and the image bearing member (photosensitive member), the toner on the photosensitive member is likely to be abnormally transferred to the transfer material due to discharge, and an abnormal image called so-called transfer dust occurs.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming process, an image forming apparatus and a toner which solve the above problems.

[0010]

According to the present invention, the above objects can be achieved by the following (1) to (4). (1) An electrostatic image is formed on an image bearing member, and the volume average particle diameter is 3 to 9 μm, and the ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) is 1. 01-1.25 and a toner having an average circularity of 0.950-0.995, the toner image is transferred to a transfer material directly or through an intermediate transfer member, and an image carrier of the toner image transfer image is formed. A cleaning device used in an image forming method for cleaning the above transfer residual toner, wherein a voltage is applied to a cleaning unit to form an electric field between the image carrier and the cleaning unit. The residual toner after transfer is adsorbed to the cleaning means.

(2) An electrostatic charge image is formed on the image bearing member, this is developed with toner, this toner image is transferred to a transfer material directly or via an intermediate transfer member, and the image after transfer of the toner image is formed. A toner used in an image forming process in which a transfer residual toner on a carrier is electrostatically adsorbed and cleaned by a cleaning unit to which a voltage is applied, and has a volume average particle diameter of 3 to 9
μm, the ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) is 1.01 to 1.25, and the average circularity is 0.950 to 0.995. And a toner for developing an electrostatic image.

(3) An electrostatic charge image is formed on the image carrier, is developed with the toner of (2) above, and this toner image is transferred to a transfer material directly or via an intermediate transfer member to obtain a toner image. An image forming method characterized in that the transfer residual toner on the image bearing member after transfer is electrostatically adsorbed and cleaned by a cleaning unit to which a voltage is applied.

(4) Using the toner of (2) above, an image carrier, a charging device for charging the image carrier, a latent image forming device for forming an electrostatic latent image on the image carrier, and an image carrier. A developing device that visualizes the electrostatic latent image by attaching toner to it, a transfer device that transfers the developed toner image to a transfer material directly or through an intermediate transfer body, and remains on the image carrier. By applying a voltage to the toner to the cleaning unit, an electric field that electrostatically attracts is formed between the image carrier and the cleaning unit, and a cleaning device that cleans transfer residual toner adhering to the image carrier is provided. An image forming apparatus having.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below. According to the present invention, (1) by applying a voltage to the cleaning means, an electric field that electrostatically attracts is formed between the image bearing body and the cleaning means, and the transfer residual toner adhering to the image bearing body is cleaned. In an electrophotographic process using a cleaning device, the toner used has a volume average particle diameter of 3 to 9 μm, and the ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) is 1.01 to
A toner having an average circularity of 1.25 and an average circularity of 0.950 to 0.995 is used. Here, the particle size and the circularity of the toner can be obtained by the following method.

Toner particle size (volume average particle size, number average particle size): Measured with a Coulter Counter Model TA-II manufactured by Coulter Electronics.

Circularity measurement method: An optical detection zone method in which a suspension containing particles is passed through a detection zone on a flat plate and a particle image is optically detected and analyzed by a CCD camera is suitable. is there. This value is the flow type particle image analyzer FPIA-
The average circularity can be measured by 1000 (manufactured by Toa Medical Electronics). As a specific measuring method, a surfactant as a dispersant, preferably 0.1 to 0.5 ml of alkylbenzene sulfonate is added to 100 to 150 ml of water in which impure solids have been removed in a container, and further measurement is performed. Sample 0.1
Add about 0.5 g. The suspension in which the sample is dispersed is obtained by performing dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser, and measuring the shape and distribution of the toner with the above-mentioned apparatus while setting the dispersion liquid concentration to 3000 to 10,000 particles / μl. .

As described in the above-mentioned prior art, in order to remove the spherical toner having a small particle size from the image carrier by a mechanical scraping effect like a blade, the contact pressure between the image carrier and the blade is required. However, in this case, if wax is contained in the toner for the purpose of eliminating the need for oil in the fixing device, the wax dispersed in the toner will seep out and the surface of the image bearing member will be exuded. Wax adheres to the film and filming occurs. Further, the cleaning blade scrapes off the image carrier more than necessary, and the life of the image carrier is shortened.

On the other hand, in the present invention, since the transfer residual toner on the image carrier is cleaned by the electrostatic force by the electric field, no mechanical stress is applied to the toner or the image carrier, so that the toner inside the toner is not removed. The dispersed wax will not exude.

The toner of the present invention has a volume average particle diameter of 3
.About.9 .mu.m, and the ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter) is 1.01 to 1.25, which is a small particle diameter but has a sharp particle diameter distribution. Since it is a toner, it has uniform charging characteristics, so
Similarly, the cleaning property of the cleaning method of the present invention is improved, and further, the toner has an average circularity of 0.950 to 0.995 and is almost spherical. Further, particularly in the case of the cleaning method of the present invention, in order to obtain good cleaning properties, it cannot be achieved unless all of the toner particle size, particle size distribution, and shape are within the above ranges.

(2) The cleaning means is preferably a cleaning roller having an elastic roller shape. As a result, the life of the image carrier can be extended. In this cleaning roller, since the elastic body rotates in the direction in which the elastic body rotates with respect to the moving direction of the image carrier, the elastic body does not rub the image carrier and the hazard to the image carrier can be reduced. it can.

(3) In the present invention, the above (1)
It is preferable that a cleaning member is provided so as to come into contact with the rotating cleaning roller of (2) to remove the toner attached to the cleaning roller. According to this, since the toner is removed from the surface of the roller that is in contact with the image carrier, it is possible to prevent reverse adhesion from the surface of the roller to the image carrier.

(4) It is preferable to reduce the cleaning failure due to the reverse polarity toner after the transfer by providing the polarity control means in the preceding stage of the cleaning means of the above (1), (2) and (3). That is, when the toner charge polarity after transfer becomes the same as the bias polarity applied to the cleaning unit or when the toners of both polarities are mixed, the transfer residual toner charge polarity is set to the polarity opposite to the bias polarity by the polarity control unit. Since they are aligned, all transfer residual toner can be cleaned well.

(5) Further, it is preferable that the cleaning means of the above (1) is a brush roller to reduce damage to the image carrier and prevent image failure due to poor cleaning. Unlike the blade, the brush roller is not abutted with a strong force, so that the brush roller also has a weak rubbing force on the image carrier, so that the photosensitive layer is not damaged. Also,
The wax dispersed inside the toner does not exude and wax filming does not occur. Even if a large amount of toner is introduced due to an abnormality such as a jam and 100% cleaning is not possible, the effect of scattering toner by the brush does not affect the output image quality.

(6) It is preferable that the brush roller of the above (5) has at least two brush rollers having different polarities. In the case of the transfer residual toner in which positive and negative polarities after transfer are mixed, if only one polarity is applied to the brush roller, one polarity toner remains. Therefore, in order to clean all the transfer residual toner regardless of the polarity of the toner, positive and negative polarities are applied to each brush roller, whereby even the transfer residual toners having different polarities can be reliably cleaned. . (7) The cleaning means of the above (1) uses both a cleaning brush that rubs the image carrier and a cleaning roller that is disposed downstream of the cleaning brush in the moving direction of the image carrier and contacts the image carrier. As a result, more excellent cleaning performance can be obtained. In brush cleaning, the tip of the brush has an excellent cleaning property due to the effect of scraping off the residual image regardless of the amount of transfer residual toner adhered, but there are cases where sweep-like cleaning defects occur. The roller cleaning can obtain good cleaning property over the entire contact width, but the transfer performance is insufficient, and the cleaning property may be deteriorated for the portion where the toner is laminated. On the other hand, since the above-mentioned cleaning brush and cleaning roller are used, brush cleaning provides sufficient cleaning performance even for a portion where a large amount of image afterimage (transfer residual toner) is attached,
By reliably performing the second stage cleaning with the roller cleaning on the sweep-like cleaning residual material, excellent cleaning performance can be exerted on any transfer residual toner. (8) Here, it is more preferable that the cleaning brush of (7) is arranged so as to rub against the cleaning roller. Although high cleaning performance can be obtained by the two cleaning means, the area occupied by the surface of the image carrier becomes large and it becomes difficult to downsize the image forming apparatus.
Particularly, in the tandem type color image forming apparatus, it is necessary to reduce the diameter of the image carrier to make the entire apparatus compact, and it is necessary to make the occupied area as small as possible. Therefore, since the cleaning brush also serves as a means for scraping off the toner from the cleaning roller and the distance between the two cleaning means is shortened, it is possible to provide an image forming apparatus capable of reducing the diameter of the image carrier.

(9) The rotation direction of the cleaning roller in the above (7) is preferably a trailing direction with respect to the moving direction of the image carrier. When the cleaning roller is rotated in the counter direction, the toner that has adhered to the cleaning roller may re-adhere to the image carrier on the downstream side of the cleaning roller if the brush roller does not scrape off the toner. To do. On the other hand, by rotating the cleaning roller in the trailing direction, even if the toner adhering to the cleaning roller cannot be scraped off by the action of the cleaning brush, the scraped-off residual toner is re-exposed to the part where the cleaning roller acts. Since it is transported and cleaned again, deterioration of cleaning performance can be avoided. Also,
Since the cleaning roller does not unnecessarily rub the image carrier, abrasion deterioration can be reduced.

(10) Further, it is preferable that the rotation direction of the cleaning brush in (7) above is a counter direction with respect to the moving direction of the image carrier. When the cleaning brush is rotated in the trailing direction, the transfer residual toner on the image carrier is made to adhere to the cleaning brush, and then the sliding movement with the cleaning roller is performed, so that the cleaning property for the cleaning roller is deteriorated. . On the other hand, by rotating the cleaning brush in the counter direction, the toner adhering to the cleaning brush is shaken off with a flicker bar to shake off the toner from the toner adhering to the brush before the toner is rotatively moved to the rubbing portion against the cleaning roller. Since the cleaning roller is rubbed after the dropping motion, it is possible to avoid the deterioration of the cleaning performance due to the rubbing of the cleaning roller. Further, the toner on the cleaning roller can be effectively scraped off, and the cleaning property is improved.

(11) In the cleaning means described in (7), it is preferable to apply voltages of different polarities to the cleaning brush and the roller. The polarity of the toner after transfer may be reversed due to charge injection or discharge phenomenon in the transfer portion, which may cause generation of toner, and electrostatic cleaning properties may not be obtained. Even in such a case, if voltages having different polarities are applied to the brush cleaning means and the roller cleaning means, the cleaning can be surely performed by either means regardless of the charging polarity of the toner.

(12) In the present invention, it is preferable that a cleaning roller is used as the cleaning means in the above (1), and the cleaning roller also serves as a charging device for uniformly charging the image carrier. That is, in the case of a color image forming apparatus or the like, a plurality of image forming units centering on the image carrier may be arranged side by side, but in that case, the image forming apparatus itself becomes large. However, if the cleaning roller also serves as the charging unit, for example, in the case of a color image forming apparatus in which a plurality of image forming units are arranged side by side,
The device can be downsized. Also, the cost can be reduced.

(13) In the cleaning means of the above (12), after the image forming operation or after the image forming operation is finished, the transfer residual toner is cleaned from the image bearing member by the cleaning roller which also functions as a charging device for uniformly charging the image bearing member. It is preferable to have a toner removing means for removing the toner adhering to the surface of the cleaning roller.
When the cleaning roller is contaminated by the transfer residual toner and the amount of contamination becomes large, the charging function of the image carrier becomes abnormal and uneven charging occurs, but the toner on the leaning roller collected by the toner removing means is Since it is quickly removed, it is possible to prevent the cleaning roller from being soiled.

(14) It is preferable that the toner removing means of the above (13) is composed of a brush and is in contact with a cleaning roller which also functions as a charging device for uniformly charging the image carrier. The cleaning roller is made of an elastic material, and if the same elastic material is used to remove the toner adhering to the surface, the stress on the toner will increase. Also,
Even if a blade is used, the stress on the cleaning roller and the toner also increases. Further, wax filming on the cleaning roller becomes a problem. With respect to these problems, stress on the toner can be reduced by using a brush to which a voltage is applied from a power source.

(15) It is preferable that a voltage is applied to the toner removing means of (14) from a power source. By applying a voltage to the toner removing means, it is possible to improve the toner removing performance from the cleaning roller and reduce the stress on the toner due to the electrostatic force.

(16) The voltage applied to the toner removing means in (15) above is preferably cleaned by using a voltage obtained by superposing a DC voltage and an AC voltage. By applying the AC voltage, it is possible to vibrate the toner on the cleaning roller and improve the toner removal performance from the cleaning roller. Further, stress on the toner can be reduced.

(17) The toner used in the present invention has a narrow particle size distribution and is a spherical toner, so that the image quality is very good, and the toner is used in the above (1) to (16).
Even if it is used in the image forming process, it does not remain after being transferred onto the image carrier as in the conventional case.

(18) The toner of (17) above may contain at least a modified polyester as a toner binder, and the wax may exist in a state of being finely dispersed in the toner. Generally, the filming of the toner on the image bearing member is often triggered by wax or pigment, but by containing the modified polyester as the binder in the toner, the fraction of wax or pigment is improved. Also, filming is less likely to occur even after long-term use of toner. In the toner of the present invention, all of the toner binder may be modified polyester, but it may be used in combination with other toner binders. In this case, it is preferable that 10% by weight or more of the total amount of the toner binder is composed of the modified polyester.

(19) The modified polyester of (18) above is preferably a modified polyester having a urea group. As a result, the dispersion of wax or pigment in the toner is further improved, and filming on the image carrier is less likely to occur.

(20) In the image forming method of the present invention, the electrostatic charge image formed on the image bearing member is developed with the toner of (17), (18) or (19), and the toner image is left as a transfer residue. After the transfer, the transfer residual toner on the image carrier is electrostatically adsorbed and cleaned by a cleaning means to which a voltage is applied. According to this method, the filming of the image carrier is performed even if the toner is used for a long time. Does not occur, and since the transfer residual toner on the image carrier can be removed cleanly, the life of the image carrier is extended and a good quality image can be formed.

(21) The image forming apparatus of the present invention uses the toner of (17), (18) or (19) above, and an image carrier, a charging device for the image carrier, and a latent image forming apparatus. ,
A device having a developing device, a transfer device, and a cleaning device to which a voltage is applied.
The effect similar to 0) is brought about.

[0038]

Embodiments of the present invention will now be described in more detail with reference to the drawings.

(Embodiment 1) FIG. 1 is a schematic view of a cleaning device of the present invention. This will be described in detail with reference to FIG.
The cleaning device has a cleaning member, a scraper blade member 3, and a carrying coil 4. The cleaning member has, for example, a rubber hardness of 15 ° to 80 around the metal shaft.
A conductive elastic layer (for example, a layer molded of conductive rubber) having a volume resistance of 10 ⁵ to 10 ¹⁵ (Ω · cm) is provided. Further, for example, a tube or coat layer made of a conductive fluororesin having a volume resistance of 10 ⁶ to 10 ¹⁶ (Ω · cm) may be provided around the rubber layer. The cleaning member is pressed against the surface of the image carrier 1 by a force of 300 to 700 (gf) by a pressure member (not shown), and 0.2 to 1.0 against the surface of the image carrier 1.
It is installed at a position having a biting amount of (mm), and the surface roughness is RZ ≦ 5 (μm).

In this embodiment, the rubber hardness 7 is set around the core metal 5.
A cleaning roller 2 provided with a conductive elastic body of 0 ° and a volume resistance of 10 ⁹ (Ω · cm) was used to press the surface of the image carrier 1 with a force of 500 (gf) by a spring to carry the image. The body 1 was installed at a position having a biting amount of 0.3 (mm). The cleaning roller 2 is rotated at the same speed as the rotation speed of the image carrier 1 by a cleaning roller 2 driving means (not shown). With the rotation of the cleaning roller 2, the transfer residual toner adhering to the cleaning roller 2 from the image carrier 1 reaches the contact portion of the scraper blade member 3 made of sheet-shaped polyurethane held by the blade holder, and the scraper blade It is peeled off from the surface of the cleaning roller 2 by 3, dropped on the rotating transport coil 4, and is discharged to the outside of the cleaning device by this transport coil 4.

FIG. 2 is a schematic view of an image forming apparatus using the cleaning device. This image forming apparatus has an arrow A
The image carrier 1 that rotates in a direction is provided, and a charging device 7, an exposure device 8, a developing device 9, a transfer device 10, a cleaning device 11, and a charge eliminating device 12 are arranged around the image carrier 1. Also,
Although not shown, a fixing device for fixing the toner image on the transfer material transferred from the image carrier 1 is arranged.

The image carrier 1 is a negatively charged OPC (organic optical semiconductor) photoreceptor in this embodiment. The image carrier 1 is
Other than the OPC photoconductor, it may be an inorganic photoconductor, an amorphous silicon photoconductor, or the like.

The charging device 7 is arranged in contact with the image carrier 1 and charges the image carrier 1 to a predetermined polarity and a predetermined potential by applying a predetermined voltage. In this embodiment, a charging roller is used to uniformly charge the image carrier 1 with a negative polarity. As the charging device 7, a scorotron charging device including an electrode wire and a grid electrode which are arranged in non-contact with the image carrier 1 may be used.

The exposure device 8 uses an LD as a light emitting element, and irradiates the image carrier 1 with light based on image data to form an electrostatic latent image. Although an LD is used in this embodiment, a light emitting element such as an LED may be used.

The developing device 9 is provided with a rotatable developer carrier having a magnet roller fixed inside for holding the developer, and a stirring and conveying screw for conveying the developer while stirring. ing. In this embodiment, two-component magnetic brush development using a two-component developer composed of toner and a magnetic carrier is used as the developer, but a one-component development which does not require a carrier may be used. A voltage is applied to the developer carrying member from a developing bias power source, and electrostatically charged toner is attached to the electrostatic latent image in the developing area to perform development. The toner used will be described later in detail.

The transfer device 10 is brought into contact with the surface of the image carrier 1 with a predetermined pressing force at the time of transfer, and a voltage is applied from a power source (not shown) so that the image carrier 1 and the transfer device 10 are contacted with each other. The toner image on the surface of the image carrier 1 is transferred to the transfer material at the transfer nip portion. In this embodiment, transfer is performed using a transfer roller. A transfer device such as a corotron or a transfer belt may be used.

The static eliminator 12 eliminates the residual charges on the image carrier 1 and uses an LED. The rotation speed of the image carrier 1 of the image forming apparatus is 200 (mm / se).
c).

After the image forming process in the image forming apparatus of FIG. 2, the image carrier 1 is sent to the cleaning device 11 part.
The upper transfer residual toner reaches a portion facing the cleaning roller 2. Table 1 shows the results of measuring the charge amount per unit weight of toner after transfer (hereinafter referred to as Q / M) after development when a solid image was formed on the image carrier 1. A solid image pattern with a fixed image area is formed on the image carrier 1.
After completion of each process such as development, transfer, and cleaning, the main switch of the image forming apparatus is forcibly turned off, and the toner image formed on the image carrier 1 is sucked by an air pump by a suction jig, Coulomb amount is measured with a coulomb meter (Kesley electrometer 611), and toner charge amount per unit weight (μC / g) is calculated from the weight of the toner sucked by the suction jig and the coulomb amount.
Was calculated.

[0049]

[Table 1]

As shown in Table 1, it was found that when the transfer voltage was changed, the Q / M of the transfer residual toner also changed. For the transfer device 10, the type of transfer material, the use environment and use mode of the image forming apparatus, and the change over time,
Process control is performed so as to absorb changes in the transfer efficiency due to various fluctuation factors, and the transfer voltage is controlled so that the best image is obtained depending on the situation.
As a result, for example, when there is a change in the transfer voltage shown in Table 1, the charge amount of the transfer residual toner on the photosensitive member changes like the transfer residual toner Q / M in Table 1.

Therefore, when a DC voltage is applied to the core 5 of the cleaning roller 2 from the power source 6, the transfer residual toner has a negative polarity as shown in Table 1, and therefore the cleaning roller 2 and the image carrier 1 are separated from each other. The toner adheres to the cleaning roller 2 by the positive electric field formed between them, and the image carrier 1 is cleaned.

In this embodiment, 700 (V) is applied to the core metal 5 of the cleaning roller 2 so that the image carrier 1 and the cleaning roller 2 have the same speed. Under this condition, the transfer residual toner is transferred to the tape, and its reflectance (I
When D) was measured, the result was 0.02, indicating that the film was cleaned well. Not limited to this condition, 400 to 80
Even at 0 (V), similarly good cleaning properties were obtained.
However, this proper bias varies depending on environmental conditions, the resistance value of the cleaning member used, the thickness, and the like. In addition,
The measuring method of the "remaining toner ID" is as follows.

Image carrier 1 after passing through the cleaning roller 2
The toner remaining on the upper cleaning is tape-transferred with a transparent tape (printer manufactured by Nitto Denko), and the image density
geDensity as an image densitometer (X-Rite93
8) and the reflectance was measured as the residual toner ID. The image density of the tape in the absence of toner was measured and used as a reference ID, and the cleaning residual toner ID was obtained by subtracting the reference ID from the residual toner ID.

The toner used in this embodiment is a toner having a specific circularity and a toner particle size distribution, preferably a toner produced by a polymerization method. The binder resin of this toner more preferably contains at least modified polyester.

Here, examples of the substituent relating to the modification of the modified polyester include a urea group and a urethane group, and examples of the polyester modified with a urea bond include a polyester prepolymer having an isocyanate group and amines. Reaction products and the like. As the polyester prepolymer having an isocyanate group,
Examples include a polycondensation product of a polyol and a polycarboxylic acid, which is obtained by further reacting a polyester having an active hydrogen group with a polyisocyanate. Examples of the active hydrogen group contained in the polyester include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group and the like, and among these, the alcoholic hydroxyl group is preferable.

When the circularity of the toner is defined as circularity = circumferential length of a circle having the same area as the projected area of the particle / contour length of the projected image of the particle, a spherical toner excellent in cleaning property by a cleaning device is selected. The comparison was made by focusing on the circularity.
Toner A (circularity 0.94), Toner B (circularity 0.9
6) and toner residual toner ID of toner C (circularity 0.98) under the same conditions are shown in Table 2. It was found that the toners B and C were superior to the toner A in electrostatic cleaning ability.

[0057]

[Table 2]

Further, Table 3 shows the same evaluation results for the toners having different toner particle size distributions (volume average particle size / number average particle size). It was found that the toner having a smaller value of volume average particle diameter / number average particle diameter has better cleaning property.

[0059]

[Table 3]

Further, the latent image formed on the image carrier 1 is developed using the toner C described above, and after transferred to the transfer material,
An image forming process of cleaning with a cleaning device was performed over a copying operation of 10,000 sheets, and the surface of the image carrier 1 was observed, but no filming substance was observed. Also, the image carrier 1 after copying 10,000 sheets
When the toner was taken out and the residual toner ID after cleaning was examined, it was equivalent to the initial stage and there was no deterioration.

As a comparative example, the same experiment was conducted using a blade cleaning device. Urethane rubber was used as the material of the cleaning blade, the biting amount was 1.05 (mm), the initial contact angle was 79 °, and the Young's modulus was 0.
45, free length 8 (mm), the blade was set in the blade holder and abutted with the above-mentioned pressure contact force and contact angle. As a result, the initial cleaning residual toner ID of the image carrier 1 was 0.01. After copying 10,000 sheets, a low-density image was observed on a part of the image, and when the photoconductor was taken out, filming occurred.

Next, the rotational speed of the cleaning roller 2 is made to have a speed difference with respect to the image carrier 1. The cleaning roller 2 is rotationally driven by a driving device so as to have a speed difference with respect to the rotational speed of the image carrier 1. Further, the toner A and the toner C described above were applied to the core metal 5 of the cleaning roller 2 by 500 (V) for the toner A and 600 (V) for the toner C.

As a result, it was found that the efficiency of removing the residual toner from the surface of the image carrier 1 was improved as shown in FIG.
As a confirmation experiment, the above-mentioned toner C is used to develop the latent image formed on the image carrier 1 and after the latent image is transferred to the transfer material, the cleaning device performs an image forming process for cleaning over 10,000 copies. The surface of the image carrier 1 was observed, but no filming substance was found. Also, the image carrier 1 after copying 10,000 sheets
When the toner was taken out and the residual toner ID after cleaning was examined, it was equivalent to the initial stage and there was no deterioration.

Next, the cleaning roller 2 and the image bearing member 1 are cleaned with the cleaning roller 2 having a static friction coefficient μ.
A cleaning speed was verified by providing a speed difference. The coefficient of static friction μOPC of the image carrier 1 and the coefficient of static friction μR of the cleaning roller are “Euler belt type” shown in FIG.
It was measured at.

The experimental conditions are: the speed difference between the cleaning roller 2 and the image carrier 1 is -207 (mm / sec) (the speed of the image carrier is 94 (mm / sec), and the cleaning roller is:
113 (mm / sec) in the counter direction), the image carrier static friction coefficient μOPC: 0.375, and the cleaning roller bias: 0 (V). As a result, when the relationship between the coefficient of static friction μOPC on the surface of the image carrier 1 and the coefficient of static friction μR of the cleaning roller is μR> μOPC, the result shows that the cleaning property is good. In this example, the case where the cleaning bias is not applied has been described, but it is possible to minimize the speed difference between the cleaning roller 2 and the image carrier 1 by applying the proper bias.

Next, when it is necessary to increase the transfer voltage due to environmental changes and deterioration over time, the charge polarity of the transfer residual toner may be reversed to positive as shown in Table 4. As it is, the cleaning of the positive polarity toner becomes defective in the cleaning by the cleaning roller 2 to which the positive polarity bias is applied.

FIG. 5 is a configuration diagram in which the polarity control means 13 is arranged before the cleaning process of the transfer residual toner by the cleaning roller 2. In this embodiment, the polarity control means 13
As power source 14 to AC100 for tungsten wire
(ΜA) and DC-60 (μA) were applied to cause corona discharge, and a negative charge was applied to the image carrier 1 and the residual toner. The residual toner Q / M after passing through the polarity control unit 13 is as shown in Table 4.

[0068]

[Table 4]

The transfer residual toner passes through the polarity control means 13 and is aligned to have a negative polarity, and then reaches a portion facing the cleaning roller 2. Here, when a DC voltage is applied to the core metal 5 of the cleaning roller 2 from the power source 6, the toner adheres to the cleaning roller 2 due to the electric field formed between the cleaning roller 2 and the image carrier 1, and the image carrier 1 Are easier to clean.

(Embodiment 2) FIG. 6 shows an embodiment. The transfer residual toner 15 on the image carrier 1 is conveyed in the CW (clockwise) direction, and is mechanically separated and dropped from the image carrier 1 by the brush roller 16 rotating in the same direction. The toner that remains on the brush roller 16 without falling off from the brush roller 16 is knocked off by the bias roller 17. At this time, the bias roller 17 may be rotating or fixed. The toner dropped from the brush roller 16 and the bias roller 17 is collected in the developing tank by the collecting roller 19 in the cleaning unit 18 and is reused. Alternatively, in order to stabilize the system, the toner may be collected in a waste toner bottle and discarded.

When the image carrier 1 is cleaned, the transfer residual toner may have polarity. Therefore, by applying the bias from the transfer bias power source 20 to the bias roller 17 and the brush tip of the brush roller 16,
An electrostatic force is applied at the same time as the mechanical force of the brush, and the cleaning property is further improved. In this example, the bias is applied via the bias roller 17, but the bias may be directly applied to the core metal of the brush roller 17. As the bias from the transfer bias power source 20, a DC voltage or an AC voltage having a polarity opposite to that of the toner, or both a DC voltage and an AC voltage may be superimposed. By this application, toners having different polarities are attracted to the brush. Also,
The polarity of the toner having polarity is erased by the application of the AC voltage, and the toner is knocked off the image carrier 1 by the mechanical force of the brush.

In the transfer step, by applying a high voltage, the toner on the image carrier 1 is electrostatically transferred onto a recording paper or an intermediate transfer medium used for color image formation. At this time, a discharge phenomenon may occur between the image carrier 1 and the transfer electrode. At this time, the polarity of the toner having a small charge amount or the toner having the abnormal polarity may be reversed by the discharge. As a result, the transfer residual toner has a non-uniform polarity. That is,
The development causes a state in which the toner having the negative polarity is mixed with the toner having the positive polarity. In order to prevent this and to make the polarity uniform, a pretreatment charging step has been provided before cleaning before. In this charging step, since a high voltage is directly applied to the image carrier 1, ozone and nitrogen oxide are generated. The influence of these generated substances on the environment and the human body has been regarded as a problem. Further, nitrogen oxides adhere to the surface of the image carrier 1 and have been a factor of image deterioration.

Therefore, the transfer residual toner for each polarity is recovered by applying a bias voltage suitable for each polarity without uniformizing the polarity by charging which is a pretreatment step.
Specifically, a positive transfer bias is applied to the brush roller 16 shown in FIG. 7, a brush roller 21 is provided further downstream, and a negative transfer bias is applied thereto. This makes it possible to clean the residual toner having mixed polarities.

FIG. 8 is a side view showing a cleaning state of residual toner on the image carrier 1. The brush roller 16 is configured by winding a brush 23, which is planted on a base cloth on the surface of a core metal 24, in a spiral shape. The base cloth is generally made of polyester nylon material. The brush 23 is straight or looped and has a density of 50,000 to 150,000 (books / i
nch ² ) Since the flocking pitch is 0.7 to 0.9 (mm), 30 to 50 raw yarn bundles are flocked at one flocking portion. The raw yarn is made of carbon-containing acrylic fiber having a thickness of 15 to 30 (μm). Since the fibers are set in a state of being bitten into the image carrier by about 1 (mm), the fibers are in a buckled state. Here, FIG. 9 shows a state in which FIG. 8 is observed from the viewing direction B (the lateral direction of the drawing). The cleaning toner 25 is captured at the tip where the brush 23 exists. However, the non-cleaning toner 26 slips between the bristles where the brush 23 is not bristled. In order to improve this, in the next row as shown in FIG. 10, the toner that has come out by flocking between the flocked rows in the preceding row is captured, and the image carrier 1 is cleaned.

That is, in particular, since the bristling intervals of the brushes are alternately planted for each row, the toner between the bristles can be reliably cleaned by the brush. Also,
The fiber diameter of the flocked is set to the following value or more from the relationship between the pitch between adjacent flocked and the number of rows to be flocked alternately, so that d ≧
P / n (d: fiber diameter of flocked, P: pitch of flocked axial direction,
n: the number of rows in the rotation direction of the flocking) By prescribing the flocking configuration, it is possible to eliminate defective cleaning toner that rolls and leaks from both sides of the brush. Further, since the brush fiber (original yarn) is composed of the main branch and the sub branch, it is possible to reliably clean the toner leaking by rolling.

FIG. 11 shows a conventional hair transplant condition. The flocking is arranged in a grid pattern with a constant pitch in rows and columns.
The flocked base fabric is manufactured by winding a pile with a constant pile width (15 to 20 mm), but the pitch of the flock is not filled. Therefore, as shown in FIG. 12, when the pitch P in the column direction and the flock diameter d, and the number of rows where the flock comes in the same position in the row direction are n, d ≧ P / n. As a result, the slip-through toner comes into contact with the brush, and the transfer residual toner is reliably captured or scraped off. As shown in FIG. 13, the brush roller 16 has a yarn length of about 5 (mm) in which the raw yarns are bundled. This raw yarn is a linear fiber as shown in FIG. 14, and if only spherical toner comes into contact with it, it slips through and defective cleaning occurs. In order to prevent this, as shown in FIG. 15, a secondary branch 28 for trapping is provided on the main branch 27 which is straightly planted. The length of the minor branch 28 is 0.05 to
By providing a slight branch-shaped protrusion of 0.1 (mm), the toner rolling off from the brush is eliminated, and the transfer residual toner is reliably contacted with the brush and the transfer residual toner is cleaned.

(Third Embodiment) FIG. 16 is a schematic diagram of a cleaning device according to another embodiment. 17 is a schematic view of an image forming apparatus using a cleaning device.
The invention of the third embodiment will be described with reference to FIG. Here, since the cleaning brush 29 is arranged so as to rub against both the image carrier 1 and the cleaning roller 30, the amount of transfer residual toner reaching the cleaning roller 30 is greatly increased by the primary cleaning effect of the cleaning brush 29. Cleaning roller 30
Since the toner can be scraped off from the apparatus without adding a scraper or a dedicated cleaning brush, it is possible to realize a small-sized and low-cost cleaning means using the high-performance cleaning roller 30.

In this cleaning means, when the rotation direction of the cleaning roller 30 is the counter direction to the image carrier 1, the toner not scraped off by the cleaning brush 29 from the cleaning roller 30 is on the downstream side of the cleaning roller 30. It will be moved to the wedge area. At this time, if the toner adheres to the image carrier 1 side in the wedge-shaped area by electrostatic or mechanical action, it will pass to the charging means as it is. Since the present invention uses the trailing direction, the toner that has not been scraped off moves again to the upstream side of the cleaning roller 30, so that the cleaning roller 30 is again subjected to the cleaning action, which may deteriorate the cleaning property. Absent.

Further, when the rotation direction of the cleaning roller 30 is the counter direction to the image carrier 1, the mechanical action force of the cleaning roller 30 becomes large, and the effect of mechanically scraping off the toner can be obtained. However, if such a configuration is adopted, the surface of the cleaning roller 30 and the surface of the image carrier 1 are rubbed with each other with a large peripheral speed difference when the amount of toner is small, so that polishing wear advances and durability deteriorates. The present invention not only eliminates the peripheral speed difference by setting the trailing direction,
By giving a peripheral speed difference of 10% or less of the speed of the image carrier 1,
An effect of mechanically scraping off can be imparted to the cleaning roller 30 to improve both cleaning performance and durability.

According to the experiments conducted by the inventors of the present invention, it was found that the effect of mechanically scraping off can be improved by applying only a few percent. Therefore, in consideration of durability, it was set to operate at 10% or less in order to establish the device with the smallest peripheral speed difference.

Since the cleaning brush 29 is also used for scraping off the toner on the image carrier 1 and the cleaning roller 30, the amount of the adhered toner is reduced by the passage of the flick cover 31, and the brush tip where the cleaning ability is recovered is
By rubbing the cleaning roller 30 on which a small amount of the cleaned toner is attached first, the scraping ability is effectively exerted, and after the amount of the attached toner is slightly increased, the amount of the attached toner on the image carrier 1 is relatively increased. Since it is configured to scrape off a large amount of adhered toner, it has excellent cleaning performance.

Cleaning brush 29 for image carrier 1
Is the counter direction and the cleaning roller 30 is the trailing direction, the cleaning brush 29 and the cleaning roller 30 are in the trailing direction, and the rubbing speed is obtained by the speed difference between the respective rollers.

The image bearing member 1 often uses an organic photosensitive member roller made of a resin material, and its surface hardness is significantly higher than that of the cleaning roller 30 made of hydrin rubber or the like. Therefore, when the cleaning brush 29 is rubbed, the image carrier 1 may be rubbed at a high speed with priority given to the improvement of cleaning performance, and the cleaning roller 30 may be rubbed at a low speed in consideration of the strength of the material. desirable. As described above, since the cleaning roller 30 and the cleaning brush 29 are in the trailing direction, in the present configuration, even if the cleaning brush 29 is used to scrape the image carrier 1 and the cleaning roller 30, The durability of 30 is not impaired.

Further, the cleaning roller 30 is preferably constructed so that an electric field in the direction of attracting toner is generated by a biasing means (not shown) at the contact portion with the image carrier, and the electrostatic attraction force is mainly used. Thus, the toner is attracted from the image carrier 1 onto the cleaning roller 30. Since such an action force is exerted regardless of the toner shape, even the spherical dry toner of this embodiment can be easily cleaned. Therefore, it is difficult to clean the spherical toner by the conventional blade cleaning method. Since the present invention realizes a spherical toner cleaning method with a small-sized and low-cost configuration that can be replaced with a blade cleaning method, it is possible to establish a small-sized, low-cost and high-quality image forming apparatus that utilizes spherical toner. Further, an image carrier 1 in which a reinforcing filler is dispersed
In some cases, the blade cleaning method could not be used. Since the present invention has realized a cleaning method for an image carrier 1 in which a reinforcing filler is dispersed with a small-sized and low-cost configuration that can be replaced with a blade cleaning method, a small-sized and low-cost method that utilizes the image carrier 1 in which a reinforcing filler is dispersed can be used. A highly durable image forming apparatus can be established.

(Embodiment 4) FIG. 18 is a schematic configuration diagram of a cleaning device according to still another embodiment. In this embodiment, as a cleaning means, a conductive cleaning roller 32 made of an elastic material is used, and it also serves as a charging device for the image carrier 1. The charging / cleaning roller 32 is arranged in contact with the image carrier 1 and rotates in the direction of arrow C. The charging / leaning roller 32 charges the image carrier 1 to a predetermined polarity and a predetermined potential by applying a voltage from the power source 33. In this embodiment, the image carrier 1
Is uniformly charged to a negative polarity.

When cleaning spherical or small toner particles with a blade, the toner is collected in a state where the toner is densely packed at the contact portion formed between the blade and the surface of the image carrier 1. The toner of the first layer, which is in direct contact with the image bearing member 1, has a strong adhesive force to the image bearing member 1, so that when cleaning with a blade, the toner of the first layer and the second layer of The toner slips between them, and the first layer pushes up the leading edge portion of the cleaning blade and passes through it, resulting in poor cleaning and remaining on the image carrier 1. Therefore, when a cleaning blade is used as the cleaning method, it is necessary to increase the contact in order to prevent defective cleaning, but a large stress is applied to the toner at the contact portion between the cleaning blade and the image carrier 1, and the toner is The wax inside may exude and adhere to the image carrier 1 to cause wax filming.

Therefore, the cleaning device of this embodiment is
Even if a toner using a sharp-melting polyester-based toner binder having a small particle size and a spherical shape and a lower melt viscosity than the conventional toner is used, the image carrier 1 can be reliably cleaned without wax filming. An elastic roller is used and cleaning is performed by applying a voltage. Further, the cleaning roller is configured to charge the surface of the image carrier 1.

The cleaning roller 32 has conductive metal particles such as carbon black, metal oxides such as titanium and aluminum, and conductive fine particles such as an ion conductive agent dispersed in an elastic material such as polyurethane rubber, silicon rubber, and brane rubber centering on a core metal 34. Has an elastic conductive layer. In addition, a middle resistance layer is provided on the surface of the cleaning roller 32 in order to prevent a bias current from leaking to the image carrier 1 due to a pinhole on the surface. In some cases, a surface protective layer may be further provided to prevent the surface of the cleaning roller 32 from being soiled. In this embodiment, the volume resistivity of the roller is used which was prepared so that ^{10 6 ~10 1 2 (Ω ·} cm). A power source 33 is connected to the cored bar 34, a voltage is applied from the power source 33 to the cleaning roller 32, and the transfer residual toner on the image carrier 1 is attracted to the cleaning roller side by an electrostatic force to perform cleaning. Cleaning can be performed by rotating the roller 32.

In this embodiment, the image carrier 1 is negatively charged, and the negatively charged toner is attached to the exposed portion.
Since it is a so-called negative-positive development method, the toner adhered on the image carrier 1 after development has a negative polarity. Therefore, since a positive voltage or current is applied to the transfer device to transfer the toner of negative polarity to the transfer material, the transfer residual toner on the image carrier 1 has its polarity inverted due to the effect of the transfer bias, and is positively charged. It is toner. Therefore, by applying a negative voltage to the cleaning roller 32, the transfer residual toner which is the positively charged toner on the image carrier 1 is cleaned.

Specifically, by applying a voltage of -1300 (V) from the power source 33 to the core metal 34 of the cleaning roller 32, the image carrier 1 is discharged by -700.
(V) is uniformly charged. Then, writing is performed by the exposure device 35 according to the input image data, and the surface potential of the image carrier 1 after exposure is set to −100 (V). The developing device 3 that holds the developer on the latent image formed in this way
A voltage of -400 (V) is applied to the developing roller in 6 to attach the toner of negative polarity to develop. The developed toner on the image carrier 1 is transferred to the transfer material 38 by the transfer roller 37 to which a voltage of +1500 (V) is applied, and the transfer residual toner having a positive polarity remains on the image carrier 1. . The surface potential of the image carrier 1 is affected by the transfer, but the surface potential of the image carrier 1 is 0 due to the static elimination light of the static eliminator 39.
(V). Then, in the cleaning step, the transfer residual toner having a positive polarity is electrostatically cleaned by the cleaning roller 32 applied with -1300 (V), and the image carrier 1 can be charged to -700 (V) again.

Charging / cleaning roller 32 of this embodiment
An image forming apparatus equipped with a cleaning device using the above and an image forming apparatus equipped with a blade cleaning device were used to confirm the occurrence of defective cleaning and the occurrence of wax filming depending on the number of prints. For filming of the wax on the image carrier 1, the static friction coefficient μ of the image carrier 1 was measured and used as a substitute characteristic. The surface friction coefficient of the image carrier 1 was measured by the "Euler belt type" as shown in FIG. Further, in the image forming apparatus using the cleaning roller 32, it was confirmed that the contamination of the roller affects the charging.

An embodiment in which the roller cleaning device is applied to another image forming apparatus will be described. FIG. 22 is a color image forming apparatus of the type in which four image forming units 50 are arranged side by side along a horizontally extending transfer belt 56 using the roller cleaning device 51 described in the first embodiment. The image forming unit 50 includes an image carrier 55, a charging device 52, an exposing device 53, a developing device 54, a roller cleaning device 51, and a charge eliminating device 58. The image forming unit 50 is for each color of yellow, magenta, cyan, and black. There are four of them. Each image forming unit 5
The developing toner developed with 0 is transferred to the transfer material 57 by the transfer belt 56 which is horizontally extended and moves in the arrow D direction to which a transfer voltage is applied.

Thus, yellow, magenta, cyan,
Black and images are formed, multiple-transferred onto a transfer material, and fixed by a fixing device (not shown). Although description has been made in the order of yellow, magenta, cyan, and black, they are not specified in this order, and they may be juxtaposed in any order.

The untransferred toner remaining on the image carrier 1 without being transferred is cleaned by the roller cleaning device 51 described in the first embodiment. However, when a cleaning blade is used, it is transferred to the image carrier 1. The wax filming reduces the friction coefficient of the image carrier 1 and
The adhesive force between the toner and the toner is reduced. Therefore, the transfer material 57
Then, before the nip of the image carrier 1, the toner on the image carrier 1 is easily transferred to the transfer material 57 by discharge, and an abnormal image called so-called transfer dust occurs. By using the cleaning device 51 according to the present embodiment, since there is no wax filming on the image carrier 1, transfer dust does not occur.
Therefore, a particularly good image can be obtained in the color image forming apparatus that requires four times of transfer in each image forming unit as in the present embodiment.

In this embodiment, the roller cleaning device of the first embodiment is used for description, but the same effects can be obtained by using the roller cleaning device of the second, third, and fourth embodiments. Further, FIG. 23 is a schematic view using a plurality of developing devices 59 to 62 using the roller cleaning device described in the first embodiment and a full-color image forming apparatus having an intermediate transfer member. The full-color image forming apparatus according to the present embodiment forms a single-color image on the image carrier 1 by a plurality of developing devices 59 to 62, and forms a full-color image by superimposing the single-color image on the intermediate transfer member 64. Is a full-color image forming apparatus that employs a method in which the color image of (1) is collectively transferred onto the transfer material 65 by the transfer device 66.

The full-color image forming apparatus includes the image carrier 6
3, charging device 68, exposure device 69, four developing devices 59
To 62, a cleaning device 67, and a static eliminator 70, four developing devices 59 to 62 are arranged for each color of yellow, magenta, cyan, and black. In this case, development is performed in the order of yellow, magenta, cyan, and black, and transfer to the intermediate transfer body 64 is performed. Finally, a full-color image of four colors is formed on the intermediate transfer body, and transferred to the transfer material 65 at once. And is fixed by a fixing device (not shown). Although description has been made in the order of yellow, magenta, cyan, and black, they are not specified in this order, and they may be juxtaposed in any order.

The untransferred toner remaining on the image carrier 1 without being transferred is cleaned by the roller cleaning device described in the first embodiment. However, when the cleaning blade is used, the wax fill on the image carrier 1 is performed. Occurs, and the wax also transfers to the intermediate transfer body, which lowers the friction coefficient between the image carrier and the intermediate transfer body, reducing the adhesive force between the image carrier and the toner and the intermediate transfer body and the toner. To do. Therefore, as described above, an abnormal image called transfer dust due to discharge occurs. The amount of dust toner increases due to transfer to the intermediate transfer member 64 (primary transfer) and transfer from the intermediate transfer member 64 to the transfer material (secondary transfer). In this embodiment, transfer dust does not occur because there is no wax filming on the image carrier 1. Therefore, as in the present embodiment, the primary transfer of each of the four colors from the image carrier 1 to the intermediate transfer member and the secondary transfer of the four-color superimposed image from the intermediate transfer member 64 to the transfer material 65 are performed five times in total. In a color image forming apparatus having a transfer step and requiring transfer, a good image without dust can be obtained.

[0098]

According to the image forming method and apparatus of the present invention,
Volume average particle diameter is 3 to 9 μm, volume average particle diameter / number average particle diameter is 1.01 to 1.25, and average circularity is 0.950.
The electrostatic charge image on the image carrier is developed with a toner of about 0.995, the toner image is transferred to a transfer machine, and the toner on the image carrier transfer machine is electrostatically charged by a cleaning means to which a voltage is applied. Since static electricity is removed by electrostatically adsorbing, toner filming does not occur on the surface of the image carrier, and a large number of good quality images can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic view of a cleaning device of the present invention.

FIG. 2 is a schematic view of an image forming apparatus using the cleaning device of the present invention.

FIG. 3 is a diagram showing a relationship between a linear velocity difference between an image carrier and a cleaning roller and a transfer toner ID.

FIG. 4 is a diagram for explaining a method of measuring μ by the Euler belt method.

FIG. 5 is a configuration diagram in which a polarity control unit is arranged in the image forming apparatus.

FIG. 6 is a schematic diagram of brush cleaning.

FIG. 7 is another schematic diagram of brush cleaning.

FIG. 8 is a state diagram showing brush cleaning.

FIG. 9 is a view of a conventional brush cleaning state as viewed from the axial direction (view B).

FIG. 10 is a view of the cleaning brush of the present invention in a state of alternately arranged flocking as viewed from the axial direction (view B).

FIG. 11 is a view showing a conventional hair transplant state.

FIG. 12 is a view showing that the hair transplants are arranged in a staggered state.

FIG. 13 is a front view of a brush roller.

FIG. 14 is a partially enlarged view of the brush roller of FIG. 13 (conventional example).

FIG. 15 is a partial enlargement of the brush roller of FIG. 13 (example of the present invention).

FIG. 16 is a schematic view of a cleaning roller device according to a third embodiment.

FIG. 17 is a schematic diagram of an image forming apparatus using the third embodiment.

FIG. 18 is a schematic diagram of a fourth embodiment (charging / cleaning roller device).

FIG. 19 is a schematic diagram of an image forming apparatus using a charging / cleaning roller device.

FIG. 20 is a diagram showing experimental results of transfer efficiency.

FIG. 21 is a diagram showing changes in the friction coefficient of a photosensitive member with and without wax filming.

FIG. 22 is a color image forming apparatus using the cleaning device of this embodiment.

FIG. 23 is a color image forming apparatus having an intermediate transfer member using the cleaning device of this embodiment.

[Explanation of symbols]

1 Image carrier 2 cleaning roller 3 Scraper blade member 4 carrier coil 5 core metal 6 power supply 7 Charging device 8 exposure equipment 9 Development device 10 Transfer device 11 Cleaning device 12 Static eliminator 13 Polarity control means 14 power supply 15 toner 16 rotating brush 17 Bias roller 18 Cleaning unit 19 rotating roller 20 Transfer bias power supply 21 brush roller 22 Bias roller 23 brushes 24 core metal 25 toner 26 Non-cleaning toner 27 Main branch 28 Side branch 29 cleaning brush 30 cleaning roller 31 Book Cover 32 cleaning roller 33 power supply 34 core metal 35 exposure device 36 Developing device 37 Transfer Roller 38 Transfer material 39 Static eliminator 40 Cleaning device 41 cleaning brush 42 core metal 43 power supply 44 Scraper blade member 45 carrier coil 50 image forming unit 51 Roller cleaning device 52 Charging device 53 Exposure equipment 54 developing device 55 Image carrier 56 transfer belt 57 Transfer material 58 Static eliminator 59, 60, 61, 62 Developing device 63 image carrier 64 Intermediate transfer body 65 Transfer material 66 Transfer device 67 Cleaning device 68 Transfer device 69 Exposure equipment 70 Static eliminator

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/24 G03G 9/08 331 21/00 314 (72) Inventor Masahiro Watanabe 1 Nakamagome Ota-ku, Tokyo 3-6, Ricoh Co., Ltd. (72) Inventor Shigeru Emoto 1-3-6 Nakamagome, Ota-ku, Tokyo In-house (72) Inc. Hiroshi Yamada 1-3-6 Nakamagome, Ota-ku, Tokyo No. in Ricoh Co., Ltd. (72) Inventor Tsuneshin Sugiyama 1-3-6 Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (reference) 2H005 AA01 AA06 AA15 CA08 CA14 CA18 DA07 EA05 2H078 AA08 BB01 BB12 CC08 DD15 DD39 DD64 DD66 EE04 2H134 GA01 GB02 HA01 HA03 HA05 HA08 HA11 HA13 HA14 HA16 HB01 HB03 HB08 HB12 HB16 HB17 HB18 HF12 JA02 KB02 KD04 KD05 KD12 KF03 KG01 KG07 KH01 KJ02 KJ05 2H200 FA 08 GA12 GA44 GA47 GA50 GB02 GB13 GB15 GB36 HA02 HB08 HB12 HB22 HB45 HB46 HB47 HB48 JA02 JB06 JB10 JC03 LB03 LB08 LB12 LB13 LB15 LB35 LB36 LB38 MA03 MA04 MA12 MA14 MA20 MB01 MB04 MC01 NA02 NA06

Claims (21)

[Claims] 1. An electrostatic charge image is formed on an image bearing member, which has a volume average particle diameter of 3 to 9 μm and a ratio of the volume average particle diameter to the number average particle diameter (volume average particle diameter / number average particle diameter). 1.01-1.
25 and a toner having an average circularity of 0.950 to 0.995, the toner image is transferred to a transfer material directly or through an intermediate transfer member, and the transfer residue on the image carrier after the toner image transfer is transferred. A cleaning device used in an image forming method for cleaning toner, wherein a voltage is applied to a cleaning unit to form an electric field between the image carrier and the image carrier and the cleaning unit. The residual toner after transfer is adsorbed to the cleaning means. 2. The cleaning device according to claim 1, wherein the cleaning means is a cleaning roller having a surface of an elastic roller. 3. The cleaning device according to claim 1, wherein the cleaning means is provided with a cleaning member so as to contact the rotating cleaning roller. 4. The cleaning device according to claim 1, further comprising a polarity control unit before the cleaning unit. 5. The cleaning device according to claim 1, wherein the cleaning means is a brush roller. 6. The cleaning device according to claim 5, comprising at least two brush rollers having different polarities. 7. The cleaning means uses a cleaning brush that slides on the image carrier and a cleaning roller that comes into contact with the image carrier that is located downstream of the cleaning brush in the moving direction of the image carrier. The cleaning device according to claim 1. 8. The cleaning brush is arranged so as to rub against the cleaning roller.
The cleaning device described in. 9. The cleaning device according to claim 7, wherein the rotation direction of the cleaning roller is a trailing direction with respect to the moving direction of the image carrier. 10. The cleaning device according to claim 7, wherein the rotation direction of the cleaning brush is a counter direction with respect to the moving direction of the image carrier. 11. The cleaning device according to claim 7, wherein voltages of different polarities are applied to the cleaning brush and the cleaning roller, respectively. 12. The cleaning device according to claim 1, wherein a cleaning roller is used as the cleaning means, and the cleaning roller also functions as a charging device for uniformly charging the image carrier. 13. An untransferred toner is cleaned from the image carrier by a cleaning roller which also functions as a charging device for uniformly charging the image carrier during or after the image forming operation and adheres to the surface of the cleaning roller. 13. The cleaning device according to claim 12, further comprising a toner removing unit that removes the remaining toner. 14. The toner removing means is constituted by a brush,
14. The cleaning device according to claim 13, wherein the cleaning device is in contact with a cleaning roller that also functions as a charging device that uniformly charges the image carrier. 15. The cleaning device according to claim 12, wherein a voltage is applied to the toner removing means from a power source. 16. The cleaning is performed by using a voltage in which a DC voltage and an AC voltage are superimposed.
The cleaning device described. 17. An electrostatic charge image is formed on an image carrier, the toner image is developed with a toner, the toner image is transferred to a transfer material directly or through an intermediate transfer member, and the image carrier after the toner image transfer is carried out. A toner used in an image forming process in which a transfer residual toner on the body is electrostatically adsorbed and cleaned by a cleaning unit to which a voltage is applied, and has a volume average particle diameter of 3 to 9 μm.
m, ratio of volume average particle diameter to number average particle diameter (volume average particle diameter /
A toner for developing an electrostatic charge image having a number average particle size of 1.01 to 1.25 and an average circularity of 0.950 to 0.995. 18. The toner for developing an electrostatic charge image according to claim 17, wherein the modified polyester is contained at least as a toner binder, and the wax is present in a finely dispersed state inside the toner. 19. The toner for developing an electrostatic charge image according to claim 18, wherein the modified polyester is a modified polyester having a urea group. 20. An electrostatic charge image is formed on an image bearing member, which is developed with the toner according to any one of claims 17 to 19, and the toner image is transferred to a transfer material directly or through an intermediate transfer member. An image forming method characterized in that the transfer residual toner after the transfer and the toner image transfer is electrostatically adsorbed and cleaned by a cleaning means to which a voltage is applied. 21. An image bearing member, a charging device for charging the image bearing member, and a latent image forming device for forming an electrostatic latent image on the image bearing member, using the toner according to any one of claims 17 to 19. When,
On the image carrier, a developing device that makes toner visible on the electrostatic latent image on the image carrier, and a transfer device that transfers the developed toner image to a transfer material directly or through an intermediate transfer body. By applying a voltage to the toner remaining on the cleaning means to the cleaning means, an electric field that electrostatically attracts is formed between the image bearing means and the cleaning means, and the transfer residual toner adhering on the image bearing means is cleaned. And an image forming apparatus.