JP2001166659A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device which has superior blade cleaning performance for an image carrier, an intermediate transfer body, and further a final transfer roll while maintaining high picture quality and high transfer performance as advantages of image formation using a spherical toner. SOLUTION: This image forming device 10 is equipped with at least an image carrier 11 where a latent image is formed, a developing device 13 which develops the latent image with the spherical toner to form a toner image, an intermediate transfer body B to which the toner image on the image carrier 11 is temporarily transferred, cleaning blades 15, 17, and 18 which remove remaining toner after transfer, and an indeterminate-shape particle supply means 1 which supplies indeterminate-shape particles to the intermediate transfer body B and further supplies the indeterminate-shape particles to the cleaning blades 15, 17, and 18 through the intermediate transfer body B.

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 using an electrophotographic method, such as a copying machine, a facsimile, a printer, etc., and more particularly, to a primary transfer step and a secondary transfer step through an intermediate transfer member. The present invention relates to an image forming apparatus using the intermediate transfer method.

[0002]

2. Description of the Related Art Conventionally, in electrophotography, an electrostatic latent image produced by charging and exposing an image carrier surface is developed with toner particles to produce a toner image, and the toner image is transferred to a transfer paper or the like. To form an image. Since untransferred toner remains on the surface of the image carrier after the transfer step, it is necessary to remove the residual toner by a cleaning unit prior to the next image forming process. Various methods such as a method using a fur brush, a magnetic brush and the like and a method using a rubber blade are used as a cleaning means for removing transfer residual toner and the like, but the image carrier is rubbed with a rubber blade. The means for scraping off toner is excellent in that it is inexpensive and easy to operate.

In recent years, particularly in a full-color image forming apparatus, a toner image is once transferred to an intermediate transfer member such as an intermediate transfer belt or an intermediate transfer drum, and is transferred to a yellow, magenta, cyan,
A process of superimposing a black toner image on an intermediate transfer body, performing collective transfer on a final transfer paper or the like, and forming a full-color image has been used. The full-color intermediate transfer system includes a single system or a single-drum system in which an image is formed with each color toner on a single image carrier, and a tandem system in which an image is formed with each color toner on a plurality of image carriers.

On the other hand, in recent years, the image quality of this type of image forming apparatus has been improved, and as one direction for improving the image quality, the diameter and the spherical shape of the toner have been promoted. By reducing the diameter of the toner, the reproducibility of the dots formed on the image carrier can be improved, and by making the toner spherical, the developability and transferability can be improved. However, simply reducing the diameter of the toner by a pulverization method, which is one of the toner production methods that have been widely used in the past, decreases the yield in producing the toner, and as a result, increases the cost of the toner. I will. Therefore, recently, instead of the conventional pulverization method, a polymerization method which is advantageous in terms of cost even if the diameter is reduced and spheroidized is attracting attention as a method for producing a small diameter and spherical toner. This polymerization method includes types such as a suspension polymerization method, an emulsion polymerization method, and a dispersion polymerization method.

[0005] However, when the small-diameter, spherical toner as described above is used, there is a problem that good cleaning performance cannot be obtained, particularly in a blade cleaning system using a rubber blade. In addition, the cleaning property is such that the smaller the particle size of the toner used for development is,
It tends to worsen as the particle size distribution becomes sharper. In the cleaning method using a rubber blade, since the toner is scraped off by rubbing the image carrier with the rubber blade as described above, the edge of the rubber blade is caused by frictional resistance between the image carrier and the rubber blade. It is deformed to form a minute wedge-shaped space. The smaller the diameter of the toner is, the easier it is to enter the space, and the entered toner is hard to be replaced, and forms a non-flow area. The frictional resistance between the toner in the non-fluid region and the image carrier is relatively small, and no cleaning failure occurs when the toner slides on the image carrier. When the frictional force between the toner and the image carrier increases due to separation or the like, the spherical toner starts to roll between the cleaning blade and the image carrier because the rolling friction is smaller than that of the conventional crushed irregular-shaped toner, and the spherical toner slips through. It is considered to be lost. Further, in the case of a spherical toner having a sharper particle size distribution, it is easier to finely pack than the irregular toner, so that it is easily compacted in a minute space near the contact point between the cleaning blade edge and the image carrier,
It is considered that the frictional force between the image carrier and the toner increases, and the toner easily rolls.

In an image forming apparatus using an intermediate transfer member, untransferred toner remains on the surface of the intermediate transfer member after the transfer step. Therefore, the residual toner is removed by cleaning means prior to the next image forming process. Although it is necessary to remove, especially in the blade cleaning method using a rubber blade, similar to the image carrier cleaning,
There is a problem that good cleaning performance cannot be obtained. The surface of the transfer roll that performs the final transfer from the intermediate transfer body to the final transfer paper is in contact with the intermediate transfer body that transfers the toner image. Means may be provided, but in particular, the blade cleaning method using a rubber blade has a disadvantage that good cleaning performance cannot be obtained as in the case of cleaning the image carrier.

[0007] In addition to the cleaning property of the spherical toner, a lubricant or the like is added to the toner for the purpose of improving the cleaning property of the toner by reducing the frictional force between the toner and the image carrier by externally adding a lubricant. The method of attaching is used. However, in this method, particularly when a spherical toner is used, it is very difficult to balance the securing of the cleaning performance of the spherical toner and the securing of the original performance required for the toner. Therefore, in an image forming apparatus using a spherical toner, a method of forming an image using a mixture of a spherical toner and an irregular toner has been proposed in order to prevent a cleaning failure of a cleaning blade. For example, there are JP-A-60-13147 and JP-A-6-148941. However, in this method, a mixture of a spherical toner and an irregular toner is used for development, and therefore, there is an advantage of a dense and uniform image or a spherical toner as compared with a case where development is performed using only a spherical toner. There is a problem that high transfer efficiency cannot be obtained.

In Japanese Patent Application Laid-Open No. Hei 8-254873, in an image forming apparatus including a plurality of developing machines of different colors, at least one developing machine contains an irregular toner and the other developing machines use a spherical toner. It has been proposed to contain toner. Also in this method, the image developed by the developing device containing the irregular toner is an advantage of the dense and uniform image and the spherical toner as compared with the case where the image is developed by the developing device containing only the other spherical toner. There is a problem that high transfer efficiency cannot be obtained. Further, the effect cannot be exhibited in the tandem type full-color image forming apparatus.

Further, in an image forming apparatus using a spherical toner, a method of supplying a lubricant or the like to an image bearing member has been proposed as another means for preventing a cleaning failure of a cleaning blade. For example, Japanese Patent Laid-Open No.
No. publication. However, if the supply of the lubricant to the image carrier is insufficient, cleaning failure occurs, and if the supply is excessive, adverse effects due to filming on the image carrier are likely to occur, so it is necessary to supply the lubricant uniformly to the image carrier over a long period of time. Yes, and very difficult to design. In recent years, the size of the apparatus has been reduced. Particularly, in an image forming apparatus using an image carrier having a small diameter, it is not possible to secure a space for a lubricant supply device that supplies a lubricant directly to the surface of the image carrier. Very difficult. In particular, in a tandem type image forming apparatus, since it is necessary to provide a lubricant supply device for each image carrier, it is very disadvantageous in terms of low cost.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and achieve the following objects. That is, the present invention provides an image carrier, an intermediate transfer body, and an image having excellent blade cleaning properties of the final transfer roll while maintaining high image quality and high transferability, which are advantages of forming an image using a spherical toner. It is an object to provide a forming device.

[0011]

Means for solving the above problems are as follows. That is, <1> an image carrier on which at least a latent image is formed, a developing device for developing the latent image with a spherical toner to form a toner image, and an intermediate device where the toner image on the image carrier is once transferred A transfer member, a cleaning blade for removing transfer residual toner after transfer, and supplying irregular particles to the intermediate transfer member, and supplying the irregular particles to the cleaning blade via the intermediate transfer member. An image forming apparatus comprising: a fixed particle supply unit. By supplying irregularly shaped particles to the cleaning blade for removing transfer residual toner after transfer via the intermediate transfer body, and supplying small-sized irregularly shaped particles to the wedge-shaped minutely deformed portion of the cleaning blade edge, Intrusion of the spherical toner into the minutely deformed portion and compaction can be suppressed. By supplying the irregular-shaped particles to the cleaning blade via the intermediate transfer member, there is no need to externally add a lubricant to the spherical toner (for image formation) or to mix the irregular-shaped toner. There is no need to sacrifice image quality and high transferability.

<2> The image forming apparatus according to <1>, further including a final transfer roll that collectively transfers the toner image on the intermediate transfer member to a final transfer material. <3> a cleaning blade for removing transfer residual toner on the image carrier, a cleaning blade for removing transfer residual toner on the intermediate transfer member,
The image forming apparatus according to <2>, wherein the image forming apparatus is at least one selected from a cleaning blade that removes transfer residual toner on a final transfer roll. <4> The image forming apparatus according to any one of <1> to <3>, wherein the irregular-shaped particle supply unit includes a magnetic conductive roll. <5> The image forming apparatus according to any one of <1> to <4>, wherein the irregular particles are supplied to the intermediate transfer member by electrostatic force, and / or the irregular particles are supplied to the cleaning blade by electrostatic force. is there. <6> The image forming apparatus according to any one of <1> to <5>, wherein at least the irregular fine powder is externally added to the irregular particles. <7> The image forming apparatus according to any one of <1> to <6>, wherein at least a lubricant is externally added to the irregular particles. <8> The image forming apparatus according to any one of <1> to <7>, wherein the irregular particles contain at least a magnetic component. <9> The image forming apparatus according to any one of <1> to <7>, wherein the irregular particles are irregular nonmagnetic particles, and are used together with a magnetic carrier. <10> The image forming apparatus according to any one of <1> to <9>, wherein the irregular particles are charged particles having a polarity opposite to that of the spherical toner. <11> The above <1>, wherein the irregular particle supply means can supply irregular particles to the intermediate transfer member at arbitrary intervals.
To the image forming apparatus according to any one of <10> to <10>.

<12> The image forming apparatus according to any one of <1> to <11>, which is a tandem full-color machine having a plurality of image carriers. Since the irregular-shaped particles are supplied via the intermediate transfer member, even in a tandem full-color image forming apparatus having a plurality of image carriers, the irregular-shaped particles are transferred to a cleaning blade for removing transfer residual toner on the plurality of image carriers. Only a single supply device is required, and cost reduction and space saving can be achieved. <13> The image forming apparatus according to <12>, wherein the irregular particle supply unit supplies irregular particles to an intermediate transfer member via at least one image carrier. In a tandem full-color machine having a plurality of image carriers, an irregular particle supply unit is provided on at least one image carrier, and the irregular particles are electrostatically developed on the image carrier. By supplying irregular particles to the intermediate transfer member and supplying the irregular particles to the cleaning blade via the intermediate transfer member, it is not necessary to sacrifice high image quality and high transferability due to the spherical toner.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The image forming apparatus of the present invention includes an image carrier, a developing device, an intermediate transfer member, a cleaning blade, and an irregular particle supply unit, and further includes other units as necessary.

[Amorphous Particle Supply Means] The image forming apparatus of the present invention supplies the irregular particles to the intermediate transfer member and supplies the irregular particles to the cleaning blade via the intermediate transfer member. It is characterized by having a particle supply means.

(Amorphous Particles) The irregular particles used in the present invention are supplied to the finely deformed wedge-shaped portion of the cleaning blade edge by supplying the irregularly shaped particles to the spherical toner (for image formation). ) Can be used without any particular limitation as long as it can suppress penetration and compaction of) and improve cleaning properties. The irregular particles are particles having various shapes, such as particles produced by a pulverization method, and have projections, ridges, and the like. The irregular shaped particles contain at least a binder resin, and further contain other components as necessary. An external additive may be added to the irregular shaped particles for use. Further, the irregular particles are irregular non-magnetic particles, and can be used together with a magnetic carrier. Further, when the irregular particles are charged particles having a polarity opposite to that of the spherical toner, there is no need to change the voltage polarity applied to the primary transfer roll during electrostatic transfer from the intermediate transfer member to the image carrier, The apparatus can be simplified.

-Binder resin- Examples of the binder resin contained in the irregular particles include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, and styrene-acrylonitrile copolymer. Known materials such as styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyethylene, polypropylene, polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, and paraffin wax can be used. Among others, styrene-acrylic copolymer,
Polyester is preferably used. These may be used alone or in combination of two or more.

-Other Components- The irregular particles may contain a magnetic component as the other component. As the magnetic component, for example, ferrite, magnetite, reduced iron, cobalt,
Metals such as nickel and manganese and alloys thereof, and compounds containing these metals are included. Further, the amorphous particles may contain, as the other components, conventionally known charge control agents, release agents, and the like contained in the toner. The addition amount of the other components is not particularly limited as long as the object of the present invention can be achieved, and can be appropriately selected.

-External additives--Amorphous fine powder-As the above-mentioned external additives, amorphous fine powders are preferred. It is difficult to produce fine-sized irregular-shaped particles with a good yield by a pulverizing method or the like. By externally adding the irregularly shaped fine powder to the irregularly shaped particles, the irregularly shaped fine powder is detached by the cleaning blade, and the small diameter irregularly shaped particles can be supplied to the cleaning blade, and the irregularly shaped particles having a relatively large average particle diameter. Even when the particles are used, the supply amount of the irregular particles to the cleaning blade is small, and the cleaning property can be efficiently improved.

Examples of the amorphous fine powder include inorganic fine powders such as metal powders and metal oxides (for example, titania, silica,
Cerium oxide, strontium titanate, silicon carbide,
Organic fine powders such as calcium carbonate, magnesium carbonate, alumina, and magnetite), polymethyl acrylate, and the like. These fine powders include coupling agents such as a silane coupling agent and a titanium coupling agent, silicone oil, and others. May be treated with an organic compound. These may be used alone or in combination of two or more.

--Lubricant-- A lubricant is preferably used as the external additive. By externally adding a lubricant to the irregular shaped particles, for example, the lubricant is separated by a cleaning blade on the image carrier and supplied to the surface of the image carrier, thereby reducing the frictional force between the image carrier and the cleaning blade. The amount of irregular-shaped particles supplied to the cleaning blade is reduced because the spherical toner is less likely to roll between the image carrier and the cleaning blade due to a reduction in the blade edge minute deformation portion and a reduction in the frictional force between the image carrier and the spherical toner. And cleaning efficiency can be efficiently improved.

Examples of the lubricant include a low molecular weight fluorine compound selected from the group consisting of polytetrafluoroethylene, a copolymer containing tetrafluoroethylene, a fluoropolyether and a compound containing a perfluoroalkyl group, and a fatty acid metal salt (for example, Metal salts of stearic acid with zinc, cadmium, barium, lead, iron, nickel, cobalt, copper, aluminum, magnesium, etc .; dibasic lead stearate; metal salts of maleic acid with zinc, magnesium, calcium, etc .; olein Acid and zinc, magnesium,
Metal salts with iron, cobalt, copper, lead, calcium, etc.),
Polyolefins, fatty acid esters, higher alcohols,
Examples include paraffin wax and silicone oil. These may be used alone or in combination of two or more.

The total amount of these external additives is preferably 0.5 to 10 parts by weight, more preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the irregular particles. When the amount added is 0.
If the amount is less than 5 parts by weight, the penetration of the spherical toner into the tip of the cleaning blade cannot be suppressed, which may result in poor cleaning. It may adhere to the body and cause image quality defects.

-Magnetic Carrier- As the magnetic carrier, a carrier whose surface is coated with a resin such as iron powder, ferrite, and magnetite, or a resin-dispersed carrier prepared by a melt-kneading and polymerization method and a resin dispersed on the surface thereof Carrier coated with the above.
When the irregular particles are irregular non-magnetic particles and used together with the magnetic carrier, supplying only the irregular non-magnetic particles to the intermediate transfer body via a magnetic conductive roll in the irregular particle supply means. As a result, uniform supply of irregularly shaped particles becomes possible similarly to the conventional two-component development, and stable and good cleaning properties are obtained.

-Particle Size of Irregular Particles-The particle diameter of the irregular particles is preferably 12 μm or less, more preferably 9 μm or less in terms of volume average particle diameter. When the volume average particle diameter exceeds 12 μm, it is difficult to penetrate into the minutely deformed portion of the cleaning blade edge, and it may not be possible to suppress the penetration of the spherical toner into the minutely deformed portion and the compaction. The volume average particle size of the irregular particles can be measured using, for example, Coulter Multisizer II (manufactured by Coulter Inc.).

On the other hand, with respect to irregularly shaped particles having remarkable projections and corners, the projected area of the irregularly shaped particles can be represented by an average particle diameter using a diameter when converted into a circle. The average particle size is, for example, FE-SEM (S-made by Hitachi, Ltd .: S-
800), randomly sample 100 irregular particle images magnified by 500 times, and the image information through an interface through an image analyzer (manufactured by NIRECO:
LuzexIII), analysis is performed, and the projection area can be obtained from the diameter when converted to a circle. The average particle size of the irregular particles thus determined is preferably 14 μm or less.

(Amorphous Particle Supply Means) The irregular particle supply means has a function of supplying the irregular particles to the intermediate transfer member and supplying the irregular particles to the cleaning blade via the intermediate transfer member. If it has, there is no particular limitation. The supply of irregular particles from the irregular particle supply means to the intermediate transfer member and the supply of irregular particles from the intermediate transfer member to the cleaning blade can be controlled by using electrostatic force to control the supply amount of irregular particles. It is easy and can be supplied stably for a long time. Further, in the supply of the irregular particles to the cleaning blade for removing the transfer residual toner on the image carrier from the intermediate transfer member, since the irregular particles can be electrostatically transferred to the image carrier using a primary transfer roll or the like, The apparatus can be simplified. When the irregular-shaped particles include a magnetic component, the irregular-shaped particle supply means preferably includes a magnetic conductive roll in that the supply of the irregular-shaped particles can be stably controlled.

Further, in a tandem full-color machine having a plurality of image carriers, an irregular particle supply means can be provided on at least one image carrier (preferably at an intermediate position between the developing device and the intermediate transfer member). . In this case, the irregularly shaped particles can be electrostatically developed on the image carrier, and the irregularly shaped particles can be supplied from the image carrier to the intermediate transfer member by electrostatic transfer. The irregular particle supply means may be provided on each of the plurality of image carriers, but from the viewpoint of cost, it is preferable to provide the irregular particle supply means only on the image carrier on which image formation is first performed. .

Hereinafter, an embodiment of the irregular particle supply means in the present invention will be described with reference to the drawings. FIG.
1 is a schematic configuration diagram illustrating an example of an irregular-shaped particle supply device 1.
The irregular particle supply means in the present invention is not limited to the irregular particle supply device shown in FIG. In the irregular-shaped particle supply device 1, a sleeve 2 is rotatably disposed at a predetermined position of the supply device main body so as to face the intermediate transfer belt B. This sleeve 2 is an intermediate transfer belt B
Is set to be about 350 to 400 μm at a close position (the irregular-shaped particle supply region A). Inside the sleeve 2, a magnetic shaft 3 in which a plurality of magnets are arranged along a peripheral surface is fixedly supported at a predetermined position of the supply device main body so as not to rotate. The magnetic shaft 3 has a magnetic pattern in which, for example, S poles and N poles serving as a plurality of magnets are arranged as shown in the drawing.
The irregular particles 6 are adsorbed on the surface of the sleeve 2 along the magnetic pattern. The sleeve 2 and the magnetic shaft 3 constitute a magnetic conductive roll.

The layer thickness regulating member 4 comprises a soft elastic body 4a pressed against the surface of the sleeve 2 and a spring plate 4b for supporting the soft elastic body 4a near one end. It is fixedly supported by the main body 1. The developing bias power supply 5 includes a high-voltage AC power supply 5a and a DC power supply 5b. The developing bias power supply 5 applies an AC voltage on which a DC voltage is superimposed to the sleeve 2 as a developing bias voltage. An alternating electric field is generated between the transfer belt B and the transfer belt B. This developing bias has, for example, a frequency of 2.4 kHz and a peak-to-peak voltage of 1
It is set to use an AC voltage of 500 V and a DC voltage of -100 V. The developing bias power supply 5
May apply a configuration in which only a DC component is applied.

[Cleaning Blade] The cleaning blade has a function of removing transfer residual toner after transfer. The material constituting the cleaning blade,
There is no particular limitation, and any conventionally known device used in an image forming apparatus may be used. In the image forming apparatus of the present invention, the cleaning blade may be a cleaning blade for removing transfer residual toner on the image carrier, or may be a cleaning blade for removing transfer residual toner on the intermediate transfer member. The cleaning blade for removing the transfer residual toner may be used, and any two or all of them may be used.

[Developing Apparatus] The developing apparatus has a function of developing a latent image formed on the image carrier with spherical toner to form a toner image. Such a developing device is not particularly limited as long as it has the above-mentioned functions, and can be appropriately selected according to the purpose. A known developing device having a function of attaching to a body may be used.

(Spherical Toner) The spherical toner used in the present invention is a toner having a high sphericity, such as a spherical toner produced by a polymerization method. The polymerization method includes a suspension polymerization method, an emulsion polymerization method, a dispersion polymerization method and the like. The particle diameter of the spherical toner is 3 to 1 by volume average particle diameter.
0 μm is preferred. The spherical toner preferably has a shape factor value (SF) calculated by the following equation of 140 or less, more preferably 130 or less. The closer the shape coefficient value is to 100, the more spherical the shape coefficient value.

[0034]

(Equation 1)

[Intermediate Transfer Body] The intermediate transfer body has a function of temporarily transferring a toner image formed on an image carrier. The structure of the intermediate transfer member is generally a single-layer structure, for example, a structure in which conductive carbon particles, metal powder, or the like is dispersed in a polyimide resin or the like. The shape of the intermediate transfer member is not particularly limited,
Although it can be appropriately selected according to the purpose, for example, a roller shape, a belt shape, and the like are preferably exemplified. In the present invention, among these, the endless belt shape is particularly preferable in terms of color misregistration at the time of superimposing images, durability due to repeated use, and ease of arrangement of other subsystems.

As the material of the intermediate transfer member, for example,
Conductive carbon for polyurethane resin, polyester resin, polystyrene resin, polyolefin resin, polybutadiene resin, polyamide resin, polyimide resin, polyvinyl chloride resin, polyethylene resin, fluorine resin, etc. Those obtained by dispersing and mixing particles, metal powder, and the like are preferably used. Among these, those obtained by dispersing carbon particles in a polyimide resin can be preferably used.

[Image Carrier] The image carrier has a function of forming at least a latent image. As the image bearing member, an electrophotographic photosensitive member is preferably exemplified. The electrophotographic photoreceptor may be a single-layer type electrophotographic photoreceptor formed by a deposited film of a charge generating substance, but in the present invention, a function-separated type electrophotographic photoreceptor can be suitably used. .

[Other Means] The other means include a charging means for charging the image carrier, an image exposing means for imagewise exposing the image, and an intermediate transfer of the toner image formed on the image carrier. A primary transfer roll having a function of transferring to the body,
A final transfer roll having a function of batch-transferring the toner image on the intermediate transfer member to a final transfer material may be used.

(Charging Means) The charging means is not particularly limited. For example, a contact type charger using a conductive or semiconductive roller, brush, film, rubber blade, or the like, a scorotron using corona discharge A charger known per se, such as a charger and a corotron charger, may be used. Among these, a contact-type charger is preferable because of its excellent charge compensation ability. The charging unit normally applies a direct current to the image carrier, but may apply an alternating current further superimposed. The image carrier is usually charged to -300 to -1000 V by, for example, such a charging unit.

(Image exposure means) As the image exposure means,
There is no particular limitation, and examples thereof include an optical device capable of exposing a light source such as a semiconductor laser light, an LED light, and a liquid crystal shutter light on the surface of the image carrier in a desired image.

(Primary Transfer Roll) A direct current is usually used as a transfer current applied from the first transfer roll to the image bearing member. In the present invention, an alternating current is further superimposed and used. You may. The setting conditions for the first transfer roll include the image area width to be charged, the shape of the transfer charger, the opening width, and the process speed (peripheral speed).
It can be set arbitrarily.

(Final Transfer Roll) A direct current is usually used as a transfer current applied from the final transfer roll (secondary transfer roll) to the intermediate transfer member. In the present invention, an alternating current is further superimposed. You may use it. The setting conditions for the final transfer roll can be arbitrarily set depending on the image area width to be charged, the shape of the transfer charger, the opening width, the process speed (peripheral speed), and the like.

An embodiment of the image forming apparatus of the present invention will be described below with reference to the drawings. FIG. 2 is a schematic configuration diagram illustrating an example of the image forming apparatus of the present invention. The image forming apparatus of the present invention is not limited to the image forming apparatus shown in FIG. The image forming apparatus in FIG. 2 is a tandem-type full-color image forming apparatus 10 that forms toner images of four colors of Y (yellow), M (magenta), C (cyan), and K (black), respectively. Image carrier (11
y, 11m, 11c, 11k). As the image carrier, a negatively chargeable organic photoreceptor is used.

Each image carrier (11y, 11m, 11c, 1
1k) are the respective chargers (12y, 12m, 12
c, 12k), an electrostatic latent image is formed on the surface by the modulated laser beam (Ly, Lm, Lc, Lk). The image carrier (11y, 1
1m, 11c, 11k), the electrostatic latent image on the surface is
3y, 13m, 13c, 13k). The developed toner image is transferred to the primary transfer area (Q
1y, Q1m, Q1c, Q1k) and the primary transfer roll (1
4y, 14m, 14c, and 14k) to be transferred onto the intermediate transfer belt (intermediate transfer member) B. A positive bias is applied to the primary transfer roll from a power source (not shown), so that negative toner can be electrostatically transferred.

Image carriers (11y, 11m, 11c, 11)
k) is an image carrier cleaner (15y, 15m, 15c) composed of a urethane rubber blade in which the residual toner on the surface of the image carrier is transferred to the intermediate carrier B in the counter direction after the toner image is transferred onto the intermediate carrier B. , 15k). The image carrier (11y, 11m, 11c, 11
k) formed in the primary transfer area (Q
1y, Q1m, Q1c, and Q1k), are sequentially transferred onto the intermediate transfer belt B in a superimposed manner, and a color toner image is formed. The color toner image transferred to the intermediate transfer belt B is
In the secondary transfer area Q2, the secondary transfer roll 16 collectively transfers (secondary transfer) the final transfer paper. Incidentally, a positive bias is applied to the secondary transfer roll from a power source (not shown), so that the negative toner on the intermediate transfer member can be electrostatically transferred. After the intermediate transfer belt B transfers the toner image to the final transfer paper, the residual toner on the surface thereof is removed by an intermediate transfer belt cleaner 17 composed of a urethane rubber blade abutting on the intermediate transfer belt in the counter direction. Secondary transfer roll 16
Is adhered to the secondary transfer roll in the counter direction by a urethane rubber blade.
It is removed by the next transfer roll cleaner 18.

The irregular-shaped particle supply device 1 is provided between the intermediate transfer belt cleaner 17 and the image carrier 11y so as to face the ground roller 19 of the intermediate transfer belt B. Control is performed so that irregular-shaped particles can be supplied to the intermediate transfer member at a timing (arbitrary interval).

[0047]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited to these examples. still,
In the following description, “parts” means “parts by weight”. Example 1 An image was formed using the image forming apparatus shown in FIG. Here, Y (yellow), M (magenta),
The four color toners of C (cyan) and K (black) are approximately spherical polymerized toners having a volume average particle diameter of 5 to 6 μm and a shape coefficient (SF) of 120, and are a two-component developer having a negative electrode chargeability. Used as A magnetic one-component toner having a volume average particle diameter of 7 μm manufactured by a pulverization method was used as the irregular shaped particles. The intermediate transfer belt used was a medium-resistance intermediate transfer belt prepared by dispersing carbon black in polyimide.

Hereinafter, a method for producing a polymerized toner will be described. -Preparation of resin particle dispersion-Styrene ... 74 parts Butyl acrylate ...・ ・ ・ ・ ・ ・ ・ ・ 26 parts Acrylic acid ・ ・ ・ ・ ・ ・ ・ 2 parts 1 part of a nonionic surfactant (Nonion P-213, manufactured by NOF Corporation) and 1 part of an anionic surfactant (Nurex R, manufactured by NOF Corporation) are dissolved in 120 parts of ion-exchanged water. ,
Disperse in a flask, emulsify, and slowly mix for 10 minutes while adding ammonium persulfate (Wako Pure Chemical Industries, Ltd.)
After adding nitrogen ion-exchanged water in which 1.2 parts were dissolved and purging with nitrogen, the contents in the flask were heated in an oil bath until the temperature of the flask reached 70 ° C. while stirring, and the emulsion polymerization was continued for 6 hours. Continued. Thereafter, the reaction solution was cooled to room temperature to prepare a resin particle dispersion. Next, a part of the resin particle dispersion was left in an oven at 80 ° C. to remove water, and the properties of the residue were measured.
00 and Tg were 52 ° C.

—Preparation of Release Agent Particle Dispersion— Polyethylene Wax 100 parts (Toyo Petrolite: Polywax 725, melting point 98 ° C.) Anion interface Activator ·········· 2 parts (Nippon Oil & Fats Co., Ltd .: NUREX®) Ion-exchanged water After mixing and dissolving 300 parts or more, homogenizer (IKA
(Ultra Turrax, Inc.), and then subjected to a dispersion treatment using a pressure discharge type homogenizer to prepare a release agent particle dispersion in which release agent particles (polyethylene wax) are dispersed.

—Preparation of Colorant Dispersion (1) —Phthalocyanine Pigment 25 parts (manufactured by Dainichi Seika Co., Ltd .: PV FAST BLUE) ) Anionic surfactant 2 parts (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen RK) Ion-exchanged water ... 125 parts After mixing and dissolving the above, homogenizer (IKA
(Ultra Turrax, Inc.) to prepare a colorant dispersion (1) in which a colorant (phthalocyanine pigment) is dispersed.

-Preparation of Colorant Dispersion (2)-Yellow Pigment 15 parts (PY180 manufactured by Clariant Japan) Anion interface Activator ········· 2 parts (Nippon Oil & Fats Co., Ltd .: NUREX®) Ion exchange water ······・ ・ ・ ・ ・ After mixing and dissolving 85 parts or more, homogenizer (IKA
(Ultra Turrax) and a colorant dispersion liquid (2) obtained by dispersing a colorant (yellow pigment).
Was prepared.

—Preparation of Colorant Dispersion (3) — Magenta Pigment 15 parts (PR122 manufactured by Dainichi Seika Co., Ltd.) Nonionic surfactant 2 parts (Rikemar S-100 manufactured by RIKEN VITAMIN CO., LTD.) Anionic surfactant 2 parts (Rikemar O-120, manufactured by RIKEN Vitamin Co., Ltd.) Ion-exchanged water .... After mixing and dissolving 85 parts or more, homogenizer (IKA)
(Ultra Turrax) and a colorant dispersion (3) obtained by dispersing a colorant (magenta pigment).
Was prepared.

—Preparation of Colorant Dispersion (4) — Carbon Black 30 parts (Cabot Corp .: Regal 330) Anionic surfactant・ ・ ・ ・ ・ ・ ・ ・ ・ 2 parts (Nippon Oil & Fats Co., Ltd .: NUREX®) Ion exchange water ... 120 parts After mixing and dissolving the above, a homogenizer (IKA
(Ultra Turrax, Inc.) to prepare a colorant dispersion liquid (4) in which a colorant (carbon black) is dispersed.

[Preparation of Cyan Toner] Resin Particle Dispersion Solution 145 parts Colorant Dispersion Solution (1) 42 parts of release agent particle dispersion 36 parts of aluminum sulfate (manufactured by Wako Pure Chemical Industries, Ltd.) 0.5 parts ion-exchanged water 300 parts or more in a round stainless steel flask After being housed and dispersed by using a homogenizer (trade name: Ultra Turrax T50, manufactured by IKA), the mixture was heated with stirring to 52 ° C. in an oil bath for heating. After holding at 52 ° C. for 20 minutes,
Observation with an optical microscope confirmed that aggregated particles having an average particle size of about 4.9 μm were formed. After slowly adding 36 parts of the resin particle dispersion liquid to the aggregated particle dispersion liquid and further maintaining the heating and stirring at 52 ° C. for 30 minutes, when observed with an optical microscope, the average particle diameter is about 5.2 μm. It was confirmed that particles were formed.

The pH of the aggregated particles was 2.2. So sodium hydroxide (manufactured by Wako Pure Chemical Industries, Ltd.)
After gently adding the aqueous solution diluted to pH 7.1 and adjusting the pH to 7.1, the mixture was heated to 93 ° C. while stirring and maintained for 6 hours. Thereafter, the reaction product was filtered, sufficiently washed with ion-exchanged water, and dried using a vacuum dryer to obtain toner particles having an average particle size of 5.5 μm.

[Preparation of Cyan Developing Agent] 100 parts of ferrite particles (manufactured by Powder Tech, average particle size: 50 μm) and a methacrylate resin (manufactured by Mitsubishi Rayon, molecular weight 950)
00) and 1.5 parts were placed in a pressurized kneader together with 500 parts of toluene, stirred and mixed at room temperature for 15 minutes, then heated to 70 ° C. while mixing under reduced pressure, and toluene was distilled off.
By cooling and sieving using a 105 μm sieve,
A ferrite carrier (resin-coated carrier) was produced.
This ferrite carrier and the cyan toner were mixed to prepare a two-component cyan developer having a toner concentration of 5% by weight.

[Preparation of Yellow Toner] Resin Particle Dispersion Solution 141 parts Colorant Dispersion Solution (2)・ ・ ・ ・ ・ ・ ・ 60 parts Release agent particle dispersion ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ 35 parts Aluminum sulfate (Wako Pure Chemical Industries, Ltd.) 0.5 parts Ion-exchanged water 300 parts Aggregation and fusion were performed in the same manner as in the preparation of the toner to obtain toner particles having an average particle size of 5.6 μm. A two-component yellow developer was prepared in the same manner as in the preparation of the cyan developer.

[Preparation of magenta toner] Resin particle dispersion liquid 140 parts Colorant dispersion liquid (3) ... 67 parts Release agent particle dispersion 42 parts Aluminum sulfate (Wako Pure Chemical Industries, Ltd.) 0.5 parts Ion-exchanged water 300 parts Agglomeration and fusion were performed in the same manner as in the preparation of the toner to obtain toner particles having an average particle size of 5.4 μm. A two-component magenta developer was prepared in the same manner as in the preparation of the cyan developer.

[Preparation of Black Toner] Resin Particle Dispersion 146 Parts Colorant Dispersion (4) ... 67 parts Release agent particle dispersion ... 36 parts Aluminum sulfate (Wako Pure Chemical Industries, Ltd.) 0.5 parts Ion-exchanged water 300 parts Agglomeration and fusion were performed in the same manner as in the preparation of the toner to obtain toner particles having an average particle size of 5.3 μm. A two-component black developer was prepared in the same manner as in the preparation of the cyan developer.

Hereinafter, a method for producing irregular shaped particles will be described. Binder resin: styrene-n-butyl acrylate copolymer 46 parts (copolymerization ratio 80:20, Mw = 160,000) Magnetic powder: magnetite ··· 50 parts Charge control agent: azo type Fe dye ··· 1 part Release agent: polypropylene wax ··· ··· 3 parts The mixture consisting of the above composition is heated and melted by an extruder.
After kneading, the mixture was pulverized and classified to obtain amorphous particles having a volume average particle diameter of 7 μm. To 100 parts of the irregular particles, 1.0 part of silica treated with silicone oil as irregular fine powder was mixed using a Henschel mixer to prepare irregular particles to which an external additive was added.

In the image forming apparatus shown in FIG. 1, in the preliminary cycle of the image forming cycle, the irregular particles (including the external additive) obtained above are applied to the intermediate transfer belt B from the irregular particle supply device 1. After developing, the primary transfer area (Q1y, Q1
m, Q1c, and Q1k), the irregular transfer particles were supplied from the intermediate transfer belt B to the image carrier 11 by applying a reverse polarity bias to the primary transfer roll 14 in the normal transfer. Some of the irregular particles supplied to the intermediate transfer belt B are:
The application timing of the bias of the primary transfer roll applied in the primary transfer area was controlled so that it could be supplied to the intermediate transfer belt cleaner 17 and the secondary transfer roll cleaner 18. Once every 40 prints, in the non-image forming cycle at the start of printing, supply of irregular-shaped particles to the image carrier cleaner 15, the intermediate transfer belt cleaner 17, and the secondary transfer roll cleaner 18 via the intermediate transfer belt B. Then, a running test of 10,000 sheets of full-color images was performed.

<Evaluation of Cleaning Property> The cleaning property of the image carrier after the running test was evaluated by visually transferring the image quality defect on the print and the residual toner on the image carrier after passing through the cleaning blade to a tape. The cleaning ability of the intermediate transfer belt was evaluated by visually transferring the residual toner on the intermediate transfer belt after passing through the cleaning blade to a tape. The cleaning property of the secondary transfer roll is such that dirt on the back surface of the print and the remaining toner on the secondary transfer roll after passing through the cleaning blade are transferred to the tape,
It was evaluated visually. The evaluation criteria are as follows.
The evaluation results are shown in Table 1 below. ：: Good cleaning property. X: Cleaning failure occurred.

(Example 2) In place of the irregular particles (including the external additive) in Example 1, 100 parts of the irregular particles prepared in Example 1 were treated with silicone oil as irregular fine powder. A running test was performed in the same manner as in Example 1 except that a mixture of 1.0 part of silica and 2.0 parts of cerium oxide fine particles (number average particle diameter 0.7 μm) using a Henschel mixer was used. The cleaning property was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1 below. In addition, each cleaning blade (image carrier cleaner 1)
5. The state of the edge of the intermediate transfer belt cleaner 17 and the secondary transfer roll cleaner 18) was observed with an electron microscope, and the cerium oxide fine particles released from the irregular particles (magnetic one-component toner) were effective at the blade edge tip. Has been observed.

Example 3 In Example 1, 100 parts of the irregular particles prepared in Example 1 were treated with silicone oil as an irregular fine powder instead of the irregular particles (including external additives). 1.0 part of silica and zinc stearate fine particles (number average particle diameter 0.5 μm) 2.0 as a lubricant
And a running test was carried out in the same manner as in Example 1, except that the mixture was mixed with a Henschel mixer, and the interval of supplying irregular-shaped particles was set to once per 100 prints. The cleaning property was evaluated. The evaluation results are shown in Table 1 below.

Comparative Example 1 A running test was performed in the same manner as in Example 1 except that no irregular-shaped particles were supplied, and the cleaning property was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 1 below.

[0066]

[Table 1]

From the results shown in Table 1, it can be seen that the image forming apparatuses of Examples 1 to 3 of the present invention have good cleaning properties in all of the image carrier, the intermediate transfer belt and the secondary transfer roll. On the other hand, in a conventional image forming apparatus that does not supply irregular-shaped particles, cleaning failure occurs on 1,000 sheets or less.

[0068]

According to the present invention, blade cleaning of an image carrier, an intermediate transfer member, and a final transfer roll while maintaining high image quality and high transferability, which are advantages of forming an image using a spherical toner, is achieved. It is possible to provide an image forming apparatus having excellent performance.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of an irregular particle supply device.

FIG. 2 is a schematic configuration diagram illustrating an example of an image forming apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Irregular particle supply device 2 Sleeve 3 Magnetic shaft 4 Layer thickness regulating member 4a Soft elastic body 4b Spring plate 5 Developing bias power supply 5a High voltage AC power supply 5b DC power supply 6 Irregular particle 10 Image forming apparatus 11y, 11m, 11c, 11k Image Carriers 12y, 12m, 12c, 12k Chargers 13y, 13m, 13c, 13k Developers 14y, 14m, 14c, 14k Primary transfer rolls 15y, 15m, 15c, 15k Image carrier cleaner 16 Secondary transfer roll 17 Intermediate transfer Belt cleaner 18 Secondary transfer roll cleaner 19 Ground roll A Amorphous particle supply area B Intermediate transfer belt Ly, Lm, Lc, Lk Laser beam Q1y, Q1m, Q1c, Q1k Primary transfer area Q2 Secondary transfer area

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Taichi Yamada 1600 Takematsu, Minamiashigara-shi, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. Inventor Hideyuki Akagi 1600 Takematsu, Minami-Ashigara-shi, Kanagawa Prefecture F-term in Fuji Xerox Co., Ltd.

Claims (13)

[Claims] 1. An image carrier on which at least a latent image is formed, a developing device for developing the latent image with spherical toner to form a toner image, and an intermediate device on which the toner image on the image carrier is once transferred A transfer member, a cleaning blade for removing transfer residual toner after transfer, and supplying irregular particles to the intermediate transfer member, and supplying the irregular particles to the cleaning blade via the intermediate transfer member. An image forming apparatus comprising: fixed particle supply means. 2. The image forming apparatus according to claim 1, further comprising a final transfer roll that collectively transfers the toner image on the intermediate transfer member to a final transfer material. 3. The cleaning blade according to claim 1, wherein the cleaning blade removes transfer residual toner on the image carrier, the cleaning blade removes transfer residual toner on the intermediate transfer member, and removes transfer residual toner on a final transfer roll. 3. The image forming apparatus according to claim 2, wherein the image forming apparatus is at least one selected from a cleaning blade. 4. The image forming apparatus according to claim 1, wherein said irregular-shaped particle supply means includes a magnetic conductive roll. 5. The image forming apparatus according to claim 1, wherein the irregular particles are supplied to the intermediate transfer member by electrostatic force, and / or the irregular particles are supplied to the cleaning blade by electrostatic force. 6. The image forming apparatus according to claim 1, wherein at least an irregular fine powder is externally added to the irregular particles. 7. The image forming apparatus according to claim 1, wherein at least a lubricant is externally added to the irregular particles. 8. The image forming apparatus according to claim 1, wherein the irregular particles contain at least a magnetic component. 9. The image forming apparatus according to claim 1, wherein the irregular particles are irregular nonmagnetic particles and used together with a magnetic carrier. 10. The image forming apparatus according to claim 1, wherein the irregular particles are charged particles having a polarity opposite to that of the spherical toner. 11. The image forming apparatus according to claim 1, wherein said irregular-shaped particle supply means can supply irregular-shaped particles to an intermediate transfer member at an arbitrary interval. 12. The image forming apparatus according to claim 1, wherein the image forming apparatus is a tandem full-color machine having a plurality of image carriers. 13. The image forming apparatus according to claim 12, wherein said irregular particle supply means supplies irregular particles to an intermediate transfer member via at least one image carrier.