JPH0535071A - Image forming device - Google Patents

Abstract

PURPOSE:To obtain a clear image which does not have surface staining and which has high quality by holding enough toner adhering amount on a developer carrier and also forming a toner layer which is in a multi-layered state and which has enough and uniform electrostatical charge amount. CONSTITUTION:A dielectric part and a conductive part co-exist on the surface of the developer carrier 20 with a minute area, and also at least the surface of a toner supplying roller 40 is constituted of a member which is >=10<3>OMEGA.cm. When this device is used in an image forming method in which charge is selectively held on the surface of the developer carrier 20, so that many minute closed electric fields are formed in the vicinity of the surface of the developer carrier, and non-magnetic one component system developer constituted of the toner 60 to which adjuvant is externally attached is supplied as necessary, the minute closed electric field makes the developer carried on the surface of the developer carrier, and the carried developer makes an electrostatic latent image visualized; enough toner adhering amount can be held on the developer carrier 20, and also uniform and enough electrostatical charge amount can be applied to the toner 60.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention supplies a non-magnetic one-component type developer to which an auxiliary agent is externally added, if necessary, to a developer carrier which is rotationally driven, and which is applied to the surface of the developer carrier. The developer is carried and conveyed, and the electrostatic latent image formed on the latent image carrier is carried on the developer carrier in a developing area where the latent image carrier and the developer carrier face each other. The present invention also relates to an image forming apparatus that visualizes with the developer.

[0002]

2. Description of the Related Art In an image forming apparatus such as an electronic copying machine, a printer, or a facsimile, which forms an electrostatic latent image on a latent image carrier and visualizes it with a developer to obtain a recorded image, a powdery material is used. A dry type developing device using a developer is widely adopted.

As the powdery developer, a two-component type developer containing a toner and a carrier and a one-component type developer not containing a carrier are known, and the former two-component type developer is used. The two-component development method can obtain a relatively stable and good recorded image, but on the other hand, deterioration of the carrier and variation of the mixing ratio of the toner and the carrier are likely to occur, maintenance of the apparatus is complicated, and the entire structure of the apparatus is large. It has a drawback that it is easy to change.

From this point of view, a one-component developing system using a one-component developer which does not have the above-mentioned drawbacks has been attracting attention. The one-component developer consists of toner only,
In some cases, an auxiliary agent is externally added to the toner if necessary and the toner and the auxiliary agent are mixed. As the toner, there are a magnetic toner in which magnetic powder is kneaded into each toner particle itself, and a non-magnetic toner containing no magnetic substance. Here, since the magnetic substance is generally opaque, when a color image including full color and multi-color is formed with magnetic toner, the developed visible image becomes unclear, and a vivid color image cannot be obtained. Therefore, especially for color development, it is desirable to adopt the one-component development method using non-magnetic toner.

By the way, in a developing device adopting a one-component developing system, a one-component developer is carried on a developer carrier and conveyed, and the developer carrier and the latent image carrier are opposed to each other. In the area, the electrostatic latent image formed on the latent image carrier is visualized by a developer, but in order to form a high-quality visible image with a predetermined density, a large amount of sufficiently charged toner is used. It is necessary to convey the latent image to a visible image by transporting it to the developing area.

When a magnetic toner is used, the magnetic force of a magnet provided in the developer carrier can be used to carry the one-component developer on the carrier, so that the above-mentioned requirements are relatively easy. It is possible to meet

However, when a non-magnetic one-component developer is used, it cannot be carried on the developer carrying member by magnetic force, so that it is difficult to satisfy the above-mentioned requirements. Various countermeasures against this have been proposed in the past,
For example, in Japanese Unexamined Patent Publication No. 61-42672, a layer of a dielectric (insulator) is laminated on the surface of a developer carrying member (developing roller), and a developer supplying member including, for example, a sponge roller. Are pressed against each other to frictionally charge them with opposite polarities, and the non-magnetic toner charged with the opposite polarity to this dielectric is electrostatically attached to the dielectric, and the one-component developer is conveyed to the developing area. The method of doing is proposed.
However, even with this method, the strength of the electric field formed in the vicinity of the dielectric surface cannot be sufficiently increased.
It is difficult to carry a large amount of toner on the surface of the developing roller, the amount of developer that can be conveyed to the developing area is insufficient, and it is difficult to form a high-density visible image.

A configuration is also known in which an electric field is applied between the developing roller and the developer supplying member in a direction in which the non-magnetic toner is electrostatically transferred to the developing roller side, but such a configuration is added. However, it is difficult to attach a sufficient amount of toner to the developing roller.

As the toner supply member, 10 ² to
Conductive foam of 10 ⁶ Ω · cm (Japanese Patent Laid-Open No. 60-2290)
67), an elastic body with a skin layer (JP-A-60-22).
9060) and fur brush (Japanese Patent Laid-Open No. 61-42).
No. 672), and as a developing roller, a metal body having irregularities on the surface (Japanese Patent Laid-Open No. 60-53976) and an insulating coated roller body (Japanese Patent Laid-Open No. 55-46768) are proposed. JP-A-58-132768), an electrode roller having an insulating surface and a conductive surface (JP-A-53-36245), and the like are disclosed.

Further, in a developing device using a non-magnetic one-component developer, JP-A-60-229067 discloses a sponge roller, JP-A-62-229060 discloses an elastic roller, and JP-A-61-52663 discloses. A fur brush or the like is used to apply an electric charge to the toner by frictional electrification between the toner and the toner supply member, and the toner is electrostatically adhered to the developing roller by friction during contact with the developing roller. The toner layer is controlled by using the layer thickness regulating member (1) to develop the latent image on the photoconductor. Various materials such as an insulating material, a medium resistance material, and a laminated material are used as the material of the developing roller.

According to the method shown in these references, the toner is adhered to the developing roller by frictional charging between the toner supply member and the developing roller. It is difficult to obtain the charge,
As a result, toner adhesion is insufficient.

The optimum adhesion amount and charge amount in the non-magnetic one-component developing system will be described below. For black and white, the amount of charge is important, which is generally 10 to 20 μC.
/ G. When the value is smaller than this value, the image quality such as background stain and sharpness is deteriorated. Regarding the amount of adhesion, the amount of adhesion on the developing roller is 0.1 to 0.3 mg / cm.
Is ^2, the transfer paper is required 0.4~0.5mg / cm ^2, by the speed of the developing roller 3 to 4 times faster than the photoreceptor, covering the adhesion amount of toner ing. However, to rotate the developing roller 3 to 4 times,
There is a problem that a phenomenon "from the trailing edge of the toner", that is, a phenomenon in which, when a solid portion is developed, the density of the trailing edge portion of the image becomes high, occurs. To prevent this phenomenon,
The speed of the developing roller should be close to that of the photoconductor. In other words, increase the amount of adhesion on the developing roller,
The number of rotations must be reduced.

On the other hand, the color characteristics of the color toner are smaller than that of the black toner in terms of the degree of coloring, and in order to improve "from the rear end of the toner", it is more than that of the black toner. A deposition amount of cm ^{2 on} the developing roller is required. Regarding the charge amount, in order to obtain a stable image, it is 5 to 20 μC / g (preferably 10 μC / g).
Values of ˜15 μC / g) are desired. It is also strongly desired to prevent so-called "toner filming", in which toner adheres to the surface of the developing roller, in order to obtain a stable toner adhesion amount and toner charge amount over time.

In order to solve these problems, the inventor of the present invention has previously stated that "a one-component system development comprising a non-magnetic toner in which an auxiliary agent is externally added to a rotationally driven developer carrier, if necessary, is added. A developer is supplied, and the developer is carried on the surface of the carrier and conveyed, and a latent image formed on the latent image carrier is developed in a developing area where the latent image carrier and the developer carrier face each other. In a developing method for visualizing an electrostatic latent image with the developer carried on a developer carrier, a large number of particles are formed in the vicinity of the surface of the carrier by selectively retaining an electric charge on the surface of the developer carrier. Developing method in which a minute closed electric field is formed, the charged toner is attracted by the closed electric field, the developer is attached to and carried on the surface of the developer carrier, and the electrostatic latent image is visualized by the carried developer. And its equipment ".

According to the invention, since a large number of minute closed electric fields (microfields) are formed in the vicinity of the surface of the developer carrying member, the electric field strength can be remarkably increased as compared with the conventional case, and a sufficiently charged large amount can be obtained. It has many advantages such that the non-magnetic toner can be carried on the developer carrying member and conveyed to the developing area.

[0016]

However, even in the image forming apparatus in which a large number of microfields are formed in the vicinity of the surface of the developer carrier as described above, the dielectric property of the developer carrier may depend on the type of toner supply roller. It was found that the triboelectric charge accumulated in the area leaked and a stable toner charge amount and toner adhesion amount could not be obtained.

Therefore, an object of the present invention is to maintain the triboelectric charge accumulated in the dielectric portion of the developer carrier in which the conductive portion and the dielectric portion are mixed in a minute area in the above image forming apparatus without leaking. Another object of the present invention is to provide an image forming apparatus in which the minute closed electric field on the surface of the developer carrying member becomes stronger and a stable toner charge amount and a stable toner adhesion amount are obtained.

[0018]

As a result of intensive studies, the present inventors have found that an image forming apparatus equipped with a toner supply roller having a surface having a specific resistance value meets the above object. The present invention has been completed.

That is, according to the present invention, a large number of minute closed electric fields are formed in the vicinity of the surface of the developer carrier by selectively retaining electric charges on the surface of the developer carrier, and this developer carrier is formed. A non-magnetic one-component developer composed of a toner to which an auxiliary agent is externally added is supplied onto the body by a toner supply roller, and the developer is carried by a minute closed electric field near the surface of the developer carrying body. An image forming apparatus that visualizes an electrostatic latent image by the carried developer, wherein at least the surface of the toner supply roller is made of a member having a resistance of 10 ¹³ Ω · cm or more. An image forming apparatus is provided.

According to the image forming apparatus of the present invention, since a large number of minute closed electric fields are formed in the vicinity of the surface of the developer carrying member,
The electric field strength can be remarkably increased as compared with the conventional one, and at least the surface of the image forming apparatus is 10 ¹³ Ω.
Since the toner supply roller composed of a member having a size of at least cm is provided, a multi-layered toner layer having a uniform charge amount distribution is formed on the developer carrier, so that a sufficient toner adhesion amount can be obtained. It is possible to provide a uniform and sufficient amount of charge to the toner while maintaining the above, and as a result, it is possible to obtain a clear high-quality image free from background stain.

The image forming apparatus will be described below. FIG. 1 shows an outline centering on a developer carrier portion of a typical image forming apparatus of the present invention. In FIG. 1, the toner 60 contained in the toner tank 70 is forcibly moved to the toner supply roller 40 by the stirring blade (toner supply auxiliary member) 50, and the toner 60 is transferred to the toner supply roller 40.
Is supplied to. On the other hand, the developer carrying member (developing roller) 20 of the present invention, which has completed the development, rotates in the direction of the arrow (for example, 400 rpm) and reaches the contact portion with the toner supply roller 40. The toner supply member 40 rotates in the opposite direction to the developer carrying member 20 (for example, 300 rpm), charges the developer carrying member 20 and the toner 60, and attaches the toner 60 onto the developer carrying member 20. Further, the developer carrying member 20 rotates, and the toner adhered on the developer carrying member 20 is stabilized in charge while the thickness is controlled by the toner layer thickness regulating member (elastic blade) 30, and reaches the developing area 80. Development area 80
In, the latent image is developed by contact or non-contact development. Here, a bias such as direct current, alternating current, direct current superimposing alternating current, pulse, etc. can be applied to the developer carrying member 20 and the toner supply roller 40 as needed to control an optimum image.

Next, the mechanism of toner adhesion to the developer carrier 20 of this type (electrode type) will be described. As an example of the developer carrier 20, as shown in FIG. 2, for example, a dielectric portion and a conductor portion are formed on the surface so as to be mixed in a minute area. The size of the area is
When the shape is circular, minute areas having a diameter of 10 to 500 μm are dispersed randomly or according to a certain rule. As for the area ratio, the area of the conductor part is 2
The range of 0 to 60% is preferable.

Toner adhesion is as follows. First, the developer carrying member 20 that has completed development rotates in the direction of the arrow and contacts the toner supply roller 40. The residual toner in the non-image area that has not been developed here is mechanically and electrically scraped by the toner supply roller 40, and the dielectric portion is charged by friction. At this time, the charges of the developer carrying member 20 and the toner due to the previous development are fixed and initialized by friction. Next, the toner carried by the supply roller 40 is
It is charged by friction and electrostatically adheres to the dielectric portion of the developer carrying member 20. At this time, the polarity of the toner is opposite to that of the charge on the photosensitive member, and the dielectric portion of the developer carrying member 20 has the same polarity.

Further, the electric field on the developer carrying member 20 at this time becomes a microfield (closed electric field) as shown in FIG. 2 and has a large electric field gradient, and as shown in FIG. Can be applied in multiple layers. Also, since the toner that has adhered has a closed electric field,
The developer carrier 20 is strongly pulled to the side where it is difficult to separate.

The toner layer thickness of the toner layer is further controlled by the toner layer thickness regulating member 30 and reaches the developing area 80. The electric field between the developer carrier 20 and the electrostatic latent image carrier (photoconductor) 10 in the developing area 80 has a large electrode effect,
The toner on the developer carrying member 20 becomes an electric field that is easily attached to the electrostatic latent image carrying member 10, and development is performed.

Next, the developer carrier used in the apparatus of the present invention will be described. As described above, the developer carrier used in the present invention has a structure in which the conductor portion and the dielectric portion are mixed in a minute area on the surface thereof. Include the V-groove roller shown in FIG.

As the material used for the dielectric portion of the developer carrying member, any insulating material can be used. Just 1
It is preferably 0 ¹² Ω · cm or more. Specific examples thereof include the following organic polymers. Polyvinyl chloride, polyvinyl butyral, polyvinylidene chloride,
Polyvinyl acetate, vinyl resin such as polyvinyl formal, polyvinyl alcohol, polystyrene, styrene-
Polystyrene resins such as acrylonitrile copolymer and acrylonitrile-butadiene-styrene copolymer; polyethylene resins such as polyethylene and ethylene-vinyl acetate copolymer; acrylic resins such as polymethylmethacrylate and polymethylmethacrylate-styrene copolymer Resin: Polyacetal, polyamide, cellulose, polycarbonate, phenoxy resin, polyester, fluororesin, polyurethane, phenol resin, urea resin, melamine resin, epoxy resin, unsaturated polyester resin, silicone resin and other resin materials; natural rubber, isoprene rubber, Butadiene rubber, styrene-butadiene rubber, butyl rubber, ethylene-propylene rubber, chloroprene rubber, chlorinated polyethylene rubber, epichlorohydrin rubber, nitrile rubber, acryl rubber Rugomu, urethane rubber, polysulfide rubber, silicone rubber, fluorine rubber, silicone-modified ethylene - such as a rubber material, such as propylene rubber.

On the other hand, as the conductive material used for the conductor portion, a material of 10 ¹² Ω · cm or less, preferably 10 ⁸ Ω · cm or less can be used. Specific examples include Al and SU
In addition to metals such as S, Fe, and Ni, ceramics, and the like, organic polymers to which a conductivity-imparting agent is added are listed. In this case, examples of the organic polymers include the same as those exemplified as the dielectric material.

Further, as the conductivity-imparting agent, Ni, Cu
Metal powder such as; fornes black, lamp black,
Carbon black such as thermal black, acetylene black, channel black; tin oxide, zinc oxide,
Conductive oxides such as molybdenum oxide, antimony oxide, and potassium titanate; electroless plated products obtained by plating titanium oxide, mica, etc .; inorganic fillers such as graphite, metal fibers, carbon fibers, and surfactants Is mentioned. Note that an organic ion conductor in which metal ions are arranged in a polymer matrix such as polyethylene oxide or posiloxane can also be used.

Next, the toner supply roller of the present invention will be described. The toner supply roller of the present invention is characterized in that at least the surface thereof is made of a member having a resistance of 10 ¹³ Ω · cm or more. Conventional toner supply roller is 10 ⁶ Ω · c
It is composed of a conductive member having a size of m or less, and its purpose is to remove the residual charge on the surface of the developing roller or to apply an electric field between the developing roller and the toner supplying roller to improve the toner replenishing property to the surface of the developing roller. . However, according to the research conducted by the present inventors, the toner replenishing property of the image forming apparatus according to the present invention is remarkably improved by the minute closed electric field on the surface of the developing roller. Therefore, it is necessary to improve the toner replenishing property by the external electric field. In addition, if the resistance value of the toner supply roller surface is small, the charge removal effect on the surface of the developing roller also removes the charge of the frictionally charged dielectric, resulting in a reduction in the strength of the minute closed electric field. However, it was found that the charging and adhesion of the toner become unstable. After further research,
It has been found that by setting at least the surface of the toner supply roller to 10 ¹³ Ω · cm or more, a more stable toner charge amount and adhesion amount can be obtained without reducing the triboelectric charge of the derivative.

FIGS. 3A, 3B and 3C show typical examples of the toner supply roller of the present invention. (A) is 10 ¹³
A single-layer solid type toner supply roller composed of a member having a volume resistance of Ω · cm or more. In order to secure the contact nip width, which is a toner replenishment area for the developing roller, this member is preferably an elastic body, preferably a rubber hardness of 40 degrees (JIS K6401) or less. This can be manufactured by a usual molding method, for example, press molding, extrusion molding, injection molding or the like.

(B) is an example of a toner supply roller composed of an insulating sponge. This is more preferable than (a) because the hardness can be made lower and the torque due to contact with the developing roller can be reduced. Further, the sponge cell is preferably a single cell rather than an open cell. With open cells, the toner penetrates deep inside the sponge cell and solidifies, gradually causing the sponge roller to become hard. The sponge roller can be prepared by a usual method. That is, a method using a foaming agent. A method that uses by-product gas during a chemical reaction. A method of foaming by mechanical stirring. A method of vaporizing by mixing or impregnating a low boiling point volatile solvent. Although a method such as that described above can be used, a method using a foaming agent that allows foaming most stably is preferable. That is, blending an organic or inorganic foaming agent with rubber or plastic,
By heating, nitrogen gas, carbon dioxide gas, ammonia gas, hydrogen gas, etc. are generated to form cells. Specific examples of the foaming agent include azobisisobutyronitrile (AIBN) and azodicarbosoamide (A.I.B.N.).
D. C. A. ), Dinitrosopentamethylenetetramine (DPT), 4,4 ′ oxybisbenzosulfonyl hydrazide (OBSH), paratoluenesulfonyl hydrazide (TSH) and the like. Can be mentioned. These are silicone rubber, urethane rubber, E
For rubber members such as PDM (ethylene-propylene-diene-methylene rubber), SBR (styrene-butadiene rubber), chloroprene rubber, natural rubber and base materials made of plastics such as polyethylene, polypropylene, polystyrene, polyvinyl chloride and ABS resin. , Predetermined expansion ratio,
It may be added depending on the processing method.

(C) is an example in which a surface layer is laminated on the toner supply roller in order to reduce the torque with the developing roller and prevent the toner from sticking to the surface of the toner supply roller.
This can be manufactured by coating the toner supply roller having the structure (a) with, for example, a soft resin by a method such as spraying or dipping. In this case, the soft resin material on the surface should be 10 ¹³ Ω · cm or more, and the lower layer should be 10 ¹² Ω · cm.
・ It may be less than or equal to cm.

[0034]

EXAMPLES Next, the present invention will be described in more detail by way of examples. Example 1 and Comparative Example 1 Preparation of Toner Supply Roller A 6φ SUS cored bar was primed (primer No. 1).
9; manufactured by Shin-Etsu Scientific Co., Ltd.) and air dried for 30 minutes. Insulating silicone rubber compound (SH35U; made by Torre Dow Corning Silicone, 3 × 10 ¹⁶ Ω · c
m, rubber hardness 30 degrees JISA) 100 parts by weight vulcanizing agent (RC-4: Toray Dow Corning Silicone Co.)
After adding 1 part by weight, 170 ° C, 10 minutes, 120 kg
Press molding was carried out under the condition of / cm ² pressure. 200 ℃,
After secondary vulcanization under the condition of 4 hours, polishing was performed and 1
A toner supply roller of Example 1 having 2φ was obtained. Conductive primer (DY39-011; Torre Dow Corning
Silicone company), conductive silicone rubber compound (DY32-700U; Toray Dow Corning Silicone company, 5 × 10 ⁵ Ω · cm, rubber curing 28 degrees JIS
A toner supply roller of Comparative Example 1 was produced in the same manner as in Example 1 except that A) was used. The toner supply roller thus manufactured was evaluated by the following method. Developing roller: Epoxy-modified silicone resin (SR2115; Toray Dow Corning Silicone Co., Ltd.) is spray-coated on the groove portion of the knurled Al cored bar,
After being hardened at 150 ° C. for 1 hour, it is polished. Groove depth: 100 μm, Pitch: 400 μm, Al area surface area occupation ratio: 25% Thinning blade: Urethane rubber Toner: Negatively charged toner Photoconductor: OPC Above toner supply roller, development roller, thin A layering blade, a toner, and a photoconductor were attached to the apparatus shown in FIG. 1, a running test was performed on 10,000 sheets, and the following items were evaluated every 2000 sheets. The results are shown in Figures 4 (a)-(c). Toner charge amount (q / m): Blow-off method Toner charge amount (m / a): Tape transfer method Development roller charging potential: Surface toner was measured after removing the adhesion toner on the surface of the development roller. It can be seen that by using the toner supply roller of No. 1, the characteristics of the developing roller are stable.

Example 2, Comparative Example 2 Toner supply roller Silicone rubber compound KE904F-U (Shin-Etsu Chemical Co., Ltd.) 1.5 parts by weight of azogosisobutyronitrile (AIBN) was added to 100 parts by weight. And 170 ℃,
After curing under the condition of 30 min, polishing was carried out to prepare a toner supply roller of Example 2 having a diameter of 12φ, which was compared with a toner supply roller made of open-cell urethane rubber (Reference Example 1). In addition to the evaluation methods and items of Example 1, the state of the toner supply roller after running 10,000 sheets was visually and touch-observed. The results are shown in Fig. 5 (a).
~ (C). In the toner supply roller after running, the hardness hardly increased in the single foam, but in the continuous foam, clogging of the toner was observed and the hardness was increased.

[0036]

According to the image forming apparatus of the present invention, since at least the surface of the toner supply roller is set to 10 ¹³ Ω · cm or more, the conductive portion and the dielectric portion are mixed in a minute area in the dielectric portion of the developer carrier. The accumulated triboelectric charge is maintained without leaking, the micro-closed electric field on the surface of the developer carrying member is further strengthened, and a stable toner charge amount and adhered amount are obtained. Further, by using a single-foam sponge roller as the toner supply roller, it is possible to prevent the hardness of the toner supply roller from rising and to obtain stable triboelectric charging.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view centering on a developer carrier portion showing an example of an image forming apparatus of the present invention for forming a microfield electric field on a developer carrier.

FIG. 2 is a schematic cross-sectional view for explaining a state in which a closed electric field due to a microfield is mainly formed on a developer carrier in the apparatus shown in FIG.

3A to 3C are schematic cross-sectional views of three typical toner supply rollers used in the apparatus shown in FIG.

4A to 4C are graphs showing the toner charge amount, the toner adhesion amount, and the charge potential of the developing carrier after the 10,000 sheets running test using the image forming apparatus of Example 1 and Comparative example 1. is there.

5A to 5C are graphs showing the toner charge amount, the toner adhesion amount, and the charge potential of the development carrier after the 10,000-sheet running test using the image forming apparatuses of Example 2 and Reference Example 1. is there.

[Explanation of symbols]

1 core 2 elastic layer 3 Sponge layer 4 surface layer 10 Electrostatic latent image carrier 20 developer carrier 30 Toner layer thickness regulating member 40 toner supply roller 50 stirring blades 60 toner 70 toner tank 80 Development area

Claims (3)

[Claims] 1. A large number of minute closed electric fields are formed in the vicinity of the surface of the developer carrying body by selectively retaining electric charges on the surface of the developer carrying body, and if necessary, on the developer carrying body. Accordingly, a non-magnetic one-component developer composed of a toner to which an auxiliary agent is externally added is supplied by a toner supply roller, and the developer is carried by a minute closed electric field in the vicinity of the surface of the developer carrying body. An image forming apparatus for converting an electrostatic latent image into a visible image, wherein at least the surface of the toner supply roller is made of a member of 10 ¹³ Ω · cm or more. 2. The image forming apparatus according to claim 1, wherein the toner supply roller is a sponge roller having a single foam cell. 3. The area ratio of the dielectric portion and the conductor portion is the conductive portion 2.
The image forming apparatus according to claim 1, wherein the image forming apparatus has an amount of 0 to 60%.