JPH07152257A - Method for forming image and device therefor - Google Patents

Abstract

PURPOSE:To provide an image forming method and image forming device by which a toner image, formed on the latent image surface of an image support, can be transferred to a recording medium without causing image flow. CONSTITUTION:The image forming method, in which an electrostatic latent image formed on a photoreceptor 10 is developed by toner and the toner image formed on the photoreceptor 10 is transferred to the recording medium, is comprised of a prewet process for coating the surface of the photoreceptor 10 with a prewet liquid, a development process for supplying the latent image surface of the photoreceptor 10 with a liquid developer having a high viscosity of 100 to 1000 mPa.s in which the toner is dispersed at a high concentration in an insulated liquid, and a transfer process for transferring the toner image formed on the photoreceptor 10 to the recording medium carried to the surface of a transfer belt 602 formed from a flexible member.

Description

Detailed Description of the Invention

[0001]

The present invention relates to electrophotography, electrostatic recording,
The present invention relates to an image forming method and an image forming apparatus in which an electrostatic latent image formed by a method such as ionography is visualized with a liquid developer and then transferred to a recording medium.

[0002]

2. Description of the Related Art Conventionally, an electrostatic latent image formed on an image support is developed with toner, which is a charged image-forming particle, and the toner image formed on the image support is transferred to a recording medium. In the image forming method, when the toner image formed on the latent image surface of the image support is transferred to the recording medium,
A transfer member charged with an electric charge having a polarity opposite to that of the toner,
This is performed by bringing the image support into contact with the recording medium.

[0003]

By the way, from the past,
Liquid developers and powder developers are examples of developers that visualize an electrostatic latent image. When a liquid developer is used, there is a problem that the image transferred to the recording medium may flow when the pressing force of the recording medium on the image support is high. In addition, in conventional large electrostatic recording devices, etc., is
About 1-2% toner in oparG (registered trademark: manufactured by Exxson)
A low-viscosity liquid developer mixed in the ratio of is used,
High-concentration and high-viscosity liquid developer (adhesive strength to the image support is increased).
When a highly viscous liquid developer (0 to 10000 mPa · s) is used, any method can be used to transfer the toner image formed on the latent image surface of the image support to the recording medium without causing image deletion. It is not clear if it is suitable.

[0004]

The present invention has been made in view of the above circumstances, and prevents the toner image from being disturbed when the toner image formed on the latent image surface of the image support comes into contact with the recording medium. Therefore, it is an object of the present invention to provide an image forming method and an image forming apparatus capable of transferring a toner image onto a recording medium without causing image deletion.

[0005]

In order to achieve the above-mentioned object, the image forming method of the present invention according to claim 1 is a method of converting an electrostatic latent image formed on an image support into a charged visible image. An image forming method of developing with a toner which is a particle, and transferring a toner image formed on the image support to a recording medium, wherein the image support has releasability before the developing step. A pre-wet process of applying a pre-wet liquid, which is a chemically inert dielectric liquid, and 100 to 10,000 mPa · s in which the toner is dispersed in the insulating liquid at a high concentration.
A developing step of supplying the high-viscosity liquid developer to the latent image surface of the image support by a developer support, and supplying the high-viscosity liquid developer to the latent image surface of the image support. A transfer step of transferring the formed toner image to a recording medium arranged on a transfer body, wherein at least one of the image support and the transfer body is formed of a flexible member. It is characterized by being.

In order to achieve the above object, the image forming method of the present invention according to claim 2 is the image forming method according to claim 1, wherein the electric resistance value of the transfer member is 10 ⁴ to 10 ¹¹ Ωc.
It is characterized by being m.

In order to achieve the above object, the image forming method of the present invention according to claim 3 is characterized in that in the invention according to claim 1 or 2, the surface of the transfer member is coated with fluorine. To do.

In order to achieve the above object, the image forming method of the present invention described in claim 4 is the image forming method according to claim 1, 2 or 3, wherein the insulating liquid of the liquid developer has a viscosity of 0. 5 to 1000 mPa · s, electric resistance 10 ¹² Ωc
m or more, surface tension 21 dyne / cm or less, boiling point 1
It is characterized in that it is at least 00 ° C.

In order to achieve the above object, the image forming method of the present invention described in claim 5 is the image forming method according to claim 4, wherein the liquid developer uses silicon oil as an insulating liquid. It is characterized by that.

In order to achieve the above-mentioned object, the image forming method of the present invention described in claim 6 is the image forming method according to claim 1, 2, 3, 4.
Alternatively, in the invention described in 5, the liquid developer contains a toner having an average particle diameter of 0.1 to 5 μm at a concentration of 5 to 40%.

In order to achieve the above object, the image forming method of the present invention according to claim 7 is the image forming method according to claim 1, 2, 3,
4, 5, or 6, the pre-wet liquid has a viscosity of 0.5 to 5 mPa · s and an electric resistance of 10 ¹² Ωc.
m or more, boiling point is 100 to 250 ° C, surface tension is 21d
It is characterized in that it is yne / cm or less.

In order to achieve the above object, the image forming method of the present invention according to claim 8 is the image forming method according to claim 7, wherein the pre-wetting liquid contains silicone oil as a main component. It is a feature.

In order to achieve the above object, in the image forming apparatus of the present invention described in claim 9, the electrostatic latent image formed on the image support is developed by toner which is charged image-forming particles. An image forming apparatus for transferring a toner image formed on the image support to a recording medium, which is a dielectric liquid having releasability and chemically inert on the image support. A pre-wetting means for applying a pre-wetting liquid, and 100 to 100 in which the toner is dispersed at a high concentration in the insulating liquid.
Developing means for supplying a high-viscosity liquid developer of 00 mPa · s to the latent image surface of the image support by a developer support;
And a transfer unit configured to transfer the toner image formed by supplying the high-viscosity liquid developer onto the latent image surface of the image support, onto a recording medium disposed on the transfer body. And at least one of the transfer bodies is formed of a flexible member.

[0014]

According to the image forming method of the present invention, the toner image formed on the latent image surface of the image support is formed by forming at least one of the image support and the transfer body with a flexible member. Since the contact pressure at the time of contact between the recording medium and the recording medium can be dispersed, the toner image can be prevented from being disturbed, and therefore the toner image can be transferred to the recording medium without causing image deletion. it can. Further, since the liquid developer in which the toner is dispersed at a high concentration is used, the liquid amount can be made much smaller than that of the conventional low concentration liquid developer. Liquid developer has a viscosity of 1
When it is 0000 mPa · s or more, it becomes difficult to stir the insulating liquid and the toner, and there is a problem in how to make the liquid developer. Therefore, 10,000 mPa · s
The liquid developer described above becomes unrealistic in terms of cost and becomes unrealistic. On the other hand, when it is 100 mPa · s or less, the toner concentration becomes low and the dispersibility of the toner becomes poor, so that it becomes impossible to develop the developer in a thin layer.
The layer thickness of the liquid developer is thin when the toner concentration is high,
It needs to be thick when it is low. In addition, the higher the viscosity, the thinner it needs to be. However, when the layer thickness is thicker than 40 μm, excessive adhesion of toner occurs and image noise occurs. On the other hand, when the layer thickness is less than 5 μm, unevenness occurs when a solid black image is output.

In the image forming method according to the second aspect, the electric resistance value of the transfer member is set to 10 ⁴ to 10 ¹¹ Ωcm,
The toner image formed on the image support can be satisfactorily transferred to the recording medium. When paper is used as the recording medium, when the transfer body is charged with an electric charge having a polarity opposite to that of the toner, if the electric resistance value of the transfer body is 10 ⁴ Ωcm or less, the image support and the transfer body are separated from each other. Even the paper sent in between may be charged. In such a case, the resistance value of the paper varies considerably depending on the type and humidity of the paper (10 ⁹ -1
0 ¹³ Ωcm), it is not appropriate because the fluctuation of the resistance value of the paper affects the transfer of the toner image formed on the image support to the paper. When the electric resistance value is 10 ¹¹ Ωcm or more, the transfer body is not sufficiently charged, the electrostatic force between the transfer body and the toner image formed on the image support is weakened, and the toner is sufficiently transferred to the paper. No longer done.

In the image forming method according to the third aspect, since the surface of the transfer body is coated with fluorine, the releasability from the toner is improved, and therefore the toner attached to the transfer body can be easily scraped off. It is possible to prevent the transfer body from becoming dirty.

In the image forming method according to the fourth aspect, a highly viscous liquid developer can be obtained by using an insulating liquid having the above characteristics. Since the liquid developer formed on the developer support is formed in a thin layer, the amount of the insulating liquid contained in the liquid developer layer is extremely small, so that it is supplied to the latent image surface of the image support. The insulating liquid contained in the liquid developer is also extremely small. Therefore, the insulating liquid absorbed by the paper or the like at the time of transfer becomes extremely small, so that the problem of the insulating liquid adhering to the paper or the like does not occur if the viscosity is 1000 mPa · s or less. However, if the viscosity is 0.5 mPa · s or less, the volatility increases, so
Not suitable because it is treated as dangerous goods. Insulating liquid has a boiling point of 10
If the temperature is 0 ° C. or less, the amount of evaporation increases, so there is a problem in the method of storing the developer, the entire device must have a closed structure, and it is difficult to improve the working environment. When the electric resistance is 10 ¹² Ωcm or less, the insulating property is deteriorated, and the toner has a problem of conductivity and cannot be used as a developer. Therefore, it is desirable that the electric resistance be as high as possible. When the surface tension is 21 dyne / cm or more, the wettability becomes poor and the compatibility with the pre-wet liquid becomes poor. Therefore, it is desirable that the surface tension be as low as possible.

According to the image forming method of the fifth aspect, the insulating liquid having silicon oil as a main component can obtain the insulating liquid having the characteristics of the fourth aspect.

In the image forming method according to the sixth aspect, the liquid developer contains the toner having the average particle diameter of 0.1 to 5 μm in the concentration of 5 to 40%, so that the toner is highly concentrated in the insulating liquid. A dispersed liquid developer can be obtained.
In addition, the resolution is improved in almost inverse proportion to the particle size of the toner. Usually, the toner is present as a lump of about 5 to 10 pieces on the printed paper, and therefore, when the average particle diameter of the toner is 5 μm or more, the resolution becomes poor. On the other hand, when the average particle diameter of the toner is 0.1 μm or less, the physical adhesive strength increases, and it becomes difficult to remove the toner during transfer.

In the image forming method according to the seventh aspect, since the pre-wetting liquid has the characteristics described above, a pre-wetting liquid having releasability and good insulation can be obtained. The pre-wetting liquid is absorbed by paper or the like at the time of transfer, and thus needs to be evaporated at the time of fixing. Therefore, the viscosity is 0.5-5 mPa.
s is desirable. If the viscosity is 5 mPa · s or more, it becomes difficult to evaporate, and if it is 0.5 mPa · s or less, the volatility becomes high. Boiling point is 10
If the temperature is 0 ° C. or less, the amount of evaporation increases, so there is a problem in the method of storing the pre-wet liquid, the entire device must have a closed structure, and it is difficult to improve the working environment. On the other hand, when the boiling point is 250 ° C. or higher, the paper is curled at the time of fixing and cannot be used, and high energy for heating is required, resulting in high cost. When the electric resistance is 10 ¹² Ωcm or less, the insulating property is deteriorated and the prewetting liquid cannot be used. Therefore, it is desirable that the electric resistance be as high as possible. Surface tension is 21
When it is more than dyne / cm, the wettability becomes poor and the compatibility with the liquid developer becomes poor. Therefore, it is desirable that the surface tension be as low as possible.

In the image forming method according to the eighth aspect, the pre-wetting liquid contains silicone oil as a main component, so that the pre-wetting liquid having the characteristics according to the seventh aspect can be obtained.

The operation of the image forming apparatus described in claim 9 is the same as the operation of the invention described in claim 1.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. 1 is a schematic configuration diagram of an image forming apparatus according to a first embodiment of the present invention, FIG. 2 is a schematic perspective view of a pre-wetting apparatus used in the image forming apparatus shown in FIG. 1, and FIG. 3 is an image forming apparatus shown in FIG. FIG. 4 is a diagram for explaining the operation of the apparatus, FIG. 4 is a diagram for explaining the operation of the prewetting apparatus shown in FIG. 2, and FIG. 5 is a prewetting solution when the prewetting solution supply member is brought into contact with the photoconductor. It is a figure showing the flow of.

Image forming apparatus 1 according to the first embodiment of the present invention
As shown in FIG. 1, the photoconductor 10 which is an image support.
A pre-wetting device 20 for applying a pre-wetting liquid onto the photoconductor 10 and a charging device 30 for charging the photoconductor 10.
An exposure device 40 that exposes an image on the photoconductor 10; and a developing device 50 that visualizes the electrostatic latent image by supplying toner to a portion of the photoconductor 10 on which the electrostatic latent image is formed. Transfer device 60 for transferring the toner on the photoconductor 10 to a predetermined paper
A paper feeding device 610 that conveys a predetermined paper onto the transfer body of the transfer device 60, a fixing device 620 that fixes the toner transferred by the transfer device 60 onto the paper, and removes the toner remaining on the photoconductor 10. The cleaning device 70 and the static eliminator 80 that neutralizes the charged photoconductor 10 are provided.

For the charging device 30, the exposure device 40, the paper feeding device 610, the fixing device 620, the cleaning device 70, and the neutralization device 80, the conventional techniques used in the conventional electrophotographic printers are used in most cases. be able to. Therefore, in the first embodiment, the description of each of the above devices is omitted, and the prewetting device 20, the developing device 50, and the transfer device 60, which are the main parts of the present invention, will be described.

As shown in FIG. 2, the pre-wetting device 20 of the first embodiment has a plate-like pre-wetting liquid supply member 202 having a length substantially the same as the image width drawn on the photoconductor 10.
And a case 2 for accommodating the pre-wet liquid supply member 202
04 and a tank 206 for storing the pre-wet liquid 220
And a pump 208 for pumping up the pre-wet liquid 220 stored in the tank 206, and tubes 210a, 210
b and a displacement device 212.

For the pre-wet liquid supply member 202, Bell Eater (registered trademark: Kanebo Co., Ltd.) is used. The bell eater is a continuous porous sponge having a three-dimensional network structure with continuous pores, capable of holding the pre-wet liquid 220 by the volume of the pores, and the pre-wet liquid 220 exceeding the volume of the pores was supplied. At times, the pre-wet liquid 220 can be uniformly discharged in a direction perpendicular to the flow direction of the pre-wet liquid 220.
An opening 204a is provided on the surface of the case 204 facing the photoconductor 10 so that the bottom surface of the prewetting liquid supply member 202 can be brought into contact with the photoconductor 10.
The tube 210 a receives the pre-wet liquid 220 drawn by the pump 208 from the pre-wet liquid supply member 20.
It is conveyed to the second supply side 202a. A space 204b is formed between the supply side 202a of the pre-wet liquid supply member 202 and the case 204.
0 is stored in this space 204b, and then the supply side 202
supplied from a. The tube 210b conveys the pre-wet liquid 220 discharged from the discharge side 202b of the pre-wet liquid supply member 202 to the tank 206. The displacement device 212, when a signal from the outside is not input,
As shown in FIG. 4A, the pre-wet liquid supply member 20.
2 is held at a position away from the photoconductor 10 and a signal from the outside is input, as shown in FIG.
The pre-wet liquid supply member 202 is brought into contact with the photoconductor 10.

The developing device 50 of the first embodiment holds the developing belt 510, which is a developer supporting member, and the developing belt 510 in such a manner that the developing belt 510 is rotationally driven and a part of the developing belt 510 is brought into contact with the photosensitive member 10. Drive rollers 512a, 5
12b and 512c and the liquid developer 508 to the developing belt 5
Coating roller 506 for coating 10 and liquid developer 508
Tank 502 for storing the liquid developer, a discharge roller 502a provided at the discharge port of the tank 502 for discharging the liquid developer 508 stored in the tank 502, and the liquid developer 508 discharged by the discharge roller 502a to the application roller 506. A supply roller 504 for supplying, a regulation means (not shown) such as a blade or a roller for adjusting the layer thickness of the liquid developer 508 applied to the developing belt 510, and a liquid developing device that adheres to the developing belt 510 after development. And a scraping blade for scraping off the agent 508.

The supply roller 504 conveys the liquid developer 508 discharged by the discharging roller 502a to the surface of the coating roller 506 by rotating in the direction opposite to the rotation direction of the coating roller 506. The coating roller 506 rotates in a direction opposite to the rotation direction of the developing belt 510 to coat the surface of the developing belt 510 with the liquid developer 508 supplied by the supply roller 504. Development belt 5
The supply roller 506 and the application roller 506 were used to supply the liquid developer 508 to the liquid developer 508 in the first embodiment, as described below, in which the liquid developer 508 in which the toner was dispersed at a high concentration was used. So you don't need a lot of developer,
Therefore, in order to apply the developer evenly to the surface of the developing belt 510, it is most effective to apply the developer with a roller. It should be noted that one or a plurality of transport rollers that transport the liquid developer 508 may be provided between the supply roller 504 and the application roller 506.

The developing belt 510 includes a driving roller 512.
The liquid developer 508 applied to the surface of the photoconductor 10 by the application roller 506 by being rotated in the direction opposite to the rotation direction of the photoconductor 10 by a, 512b, 512c.
To transport. As the developing belt 510, a flexible member such as a seamless nickel belt or a resin belt such as a polyimide belt is used. This makes it possible to disperse the contact pressure when the liquid developer layer formed on the developing belt 510 and the pre-wet liquid layer formed on the photoconductor 10 are dispersed, so that it is formed on the developing belt 510. The liquid developer layer and the pre-wet liquid layer formed on the photoconductor 10 are brought into contact with each other while maintaining a two-layer state,
Moreover, both can be separated inside the pre-wet liquid layer. The developing belt 510 must be capable of applying a developing bias. Therefore, when a resin belt is used, it is necessary to add conductive fine particles to reduce the electric resistance value or to subject the surface of the belt to conductive treatment. When the belt itself has conductivity, rubber rollers having a low electric resistance value are used as the driving rollers 512a, 512b, 512c so that a developing bias can be applied. When the surface of the belt is subjected to electro-conductivity, a conductor that comes into contact with the surface of the belt is provided, and a developing bias is applied to this conductor.

The transfer device 60 of the first embodiment drives the transfer belt 602, which is a transfer member, and rotationally drives the transfer belt 602 and holds a part of the transfer belt 602 so that the transfer belt 602 is brought into contact with the photosensitive member 10. Rollers 604a, 604
b, 604c, a corona discharger 606 for charging the transfer belt 602 with an electric charge having a polarity opposite to that of the toner, and a scraping blade 608 for scraping off the toner adhering to the transfer belt 602.

The transfer belt 602 has a driving roller 604.
The paper conveyed by the paper feeding device 610 is fed between the photoconductor 10 and the transfer belt 602 by being rotated by a, 604b, 604c in the direction opposite to the rotation direction of the photoconductor 10. The transfer belt 602 includes a rubber belt,
A flexible member such as a seamless nickel belt having a surface coated with a resistance layer or a resin belt is used.
This makes it possible to disperse the contact pressure when the toner image formed on the photoconductor 10 comes into contact with the paper.

The transfer belt 602 has an electric resistance value of 10 ⁴
It is desirable to have a resistivity of about 10 ¹¹ Ωcm. Electric resistance is 10 ⁴
If it is Ωcm or less, even the paper fed between the photoconductor 10 and the transfer belt 602 may be charged by the corona discharger 606. In such a case, the resistance value of the paper varies considerably depending on the paper type and humidity (10 ⁹ to 10 ^13).
.OMEGA.cm), which is not appropriate because the fluctuation of the resistance value of the paper affects the transfer of the toner image formed on the photoconductor 10 to the paper. When the electric resistance value is 10 ¹¹ Ωcm or more, the transfer belt 602 is not sufficiently charged, the electrostatic force between the transfer belt 602 and the toner image formed on the photoconductor 10 is weakened, and the toner is moved to the paper. Will not be fully performed.
In order to set the electric resistance value of the transfer belt 602 to the above value, when using a resin belt, it is necessary to add conductive fine particles. Further, when a polyimide film belt is used, it is necessary to subject the surface of the belt to conductive treatment.

The surface of the transfer belt 602 is coated with fluorine. This is to improve the releasability of the transfer belt 602 to prevent the toner adhering to the transfer belt 602 from being easily scraped by the scraping blade 608 and prevent the transfer belt 602 from being soiled.

Next, the image forming material used in the first embodiment of the present invention will be described. The liquid developer 508 used in the first embodiment is a resin serving as a binder such as epoxy,
A toner is composed of a charge control agent that gives a predetermined charge to the toner, a color pigment, a dispersant that uniformly disperses the toner, and the like, and a carrier liquid. The toner composition is basically similar to that used in conventional liquid developers, but their formulation has been modified to be compatible with silicone oils for adjusting charging characteristics and dispersibility. The smaller the average particle size of the toner is, the better the resolution is. However, the smaller the particle size is, the larger the physical adhesive force is, and the more difficult it is to remove when transferring. For this reason, in the first embodiment, the average particle diameter of the toner is adjusted so that the center is around 2 to 4 μm for the purpose of improving transferability.

The viscosity of the liquid developer depends on the carrier liquid used,
It depends on the resin, color pigment, charge control agent, etc. and their concentrations. In the first embodiment, the viscosity is 50-6000.
The experiment was performed by changing the mPa · s and the toner concentration in the range of 5 to 40%.

As the carrier liquid, one having a low viscosity such as dimethylpolysiloxane oil or cyclic polydimethylsiloxane oil exhibiting a high electric resistance is used. Incidentally, the developing belt 510
Since the liquid developer layer formed on top is formed in a thin layer, the carrier liquid contained in the liquid developer layer is extremely small, so that the amount of carrier liquid in the liquid developer supplied to the latent image surface of the photoconductor 10 is small. The carrier liquid contained in is very small. Therefore, the carrier liquid absorbed in the paper or the like during transfer is extremely small, and if the viscosity is 1000 mPa · s or less, almost no carrier liquid remains after fixing. According to experiments conducted by the present inventors, the carrier liquid has a viscosity of 2.5 mPa · s, DC3 manufactured by Dow Corning Co., USA.
When the image output experiment was carried out using No. 44, no carrier liquid remained on the paper after fixing. However, since the volatility is high, it is necessary to make the developing device have a closed structure.
In addition, when the image output experiment was conducted using DC345 of Dow Corning Co., USA, which has a viscosity of 6.5 mPa · s as the carrier liquid, it was fixed on paper after fixing similarly to the case where the image output experiment was conducted using DC344. No carrier liquid remained in the. However, since the volatility is high, it is necessary to make the developing device have a closed structure. Furthermore, the carrier liquid has a viscosity of 2
Shin-Etsu Silicon KF-96-20 with 0 mPa · s
No carrier liquid remained on the paper after fixing was observed when the image output experiment was carried out using. Further, since the volatility is not so high, it is not necessary to make the developing device have a closed structure. DC344, DC345 and KF-96-
20 is generally used in cosmetics and has high safety such as toxicity. There are many kinds of carrier liquids such as KF9937 manufactured by Shin-Etsu Silicon Co., Ltd., and any one may be selected as long as the electric resistance, the evaporation property, the surface tension, the safety and the like are satisfied.

Further, according to experiments conducted by the inventors, when the surface tension is large, fogging and toner lumps may adhere, and experimentally, when the surface tension is 21 dyne / cm or more, a problem of image quality is likely to occur. Do you get it.

The electric resistance value is preferably 10 ¹⁴ Ωcm or more because of the problem of toner charging stability. At least 1
0 ¹² Ωcm or more is necessary. In the description of the first embodiment,
In view of these experimental results, DC is inexpensive and easily available.
An example using 345 is shown.

The pre-wetting liquid easily evaporates during fixing without disturbing the electrostatic latent image formed on the image support,
It is required that fogging and lumps of toner do not adhere. As an example, DC34 manufactured by Dow Corning, USA
4, DC200-0.65, -1.0, -2.0, KF96L-1, KF9937 manufactured by Shin-Etsu Silicon Co., and the like. Generally, it is necessary to select a highly evaporative silicone oil.

In an experiment conducted by the inventors, the liquid viscosity was 0.
The liquid was dried by development, transfer, and fixing without problems in the range of 5 to 3 mPa · s, but from 5 mPa · s to 6 mPa · s
-At about s, there was a tendency that time and temperature were required for drying the liquid at the time of fixing. If it is 10 mPa · s, the energy required for drying becomes too large, which is not general. Also,
If it is 0.5 mPa · s or less, the volatility increases, so
Not suitable because it is treated as dangerous goods. In addition, the boiling point must be 250 ° C. or lower because of the influence of heating the paper.

The surface tension should be as low as possible in order to eliminate the adhesive force between the developer and the image support, improve the releasability and prevent the image from being soiled and fogged, and improve the image resolution and fog. Good. According to the experiments by the present inventors, 2
The limit is about 0 to 21 dyne / cm, and it is necessary to select one lower than this.

When the electric resistance is low, the latent image charge leaks to blur the image. Therefore, it is necessary to use the highest possible one. Experimentally, about 10 ¹⁴ Ωcm or more is desirable. A minimum of 10 ¹² Ωcm is required.

Next, the operation of the image forming apparatus according to the first embodiment of the present invention will be described. First, as shown in FIG. 3A, the surface of the photoconductor 10 is charged by the charging device 30. Generally, a corona discharger is used for the charging device 30. Next, the image is exposed on the charged photoreceptor 10.
For example, the image is exposed by a laser scanner to form an electrostatic latent image on the surface of the photoconductor 10. As shown in FIG. 3B, the portion of the laser scanner exposed to the light becomes conductive, so that the charge disappears, and the portion not exposed to the light remains as an electrostatic latent image which is an image of the charge.

Next, as shown in FIG. 3C, the above-described pre-wetting liquid 220 is applied onto the photoconductor 10 by the pre-wetting device 20. The pre-wetting device 20 receives the pre-wetting liquid supply member 20 when a signal from the outside is input.
2 is brought into contact with the photoconductor 10. The pre-wet liquid 220 is constantly circulated inside the pre-wet liquid supply member 202 by the pump 208.
As shown in FIG. 5, the pre-wet liquid 220 that exceeds the volume of the pores of the bell eater is 02 is discharged from the discharge side 202b of the pre-wet liquid supply member 202 and is discharged from the bottom surface of the pre-wet liquid supply member 202. The photoconductor 10 is evenly applied on the photoconductor 10 without being scratched.

Next, the electrostatic latent image is visualized by the developing device 50. The liquid developer 50 discharged from the tank 502 by the discharge roller 502a and supplied to the supply roller 504.
After being conveyed to the coating roller 506, the developing belt 8
10 is applied. The liquid developer 508 applied to the developing belt 510 forms a thin layer on the developing belt 510 with its layer thickness adjusted by a regulating means such as a blade or a roller.
The liquid developer layer thus formed on the developing belt 510 is brought close to the electrostatic latent image formed on the surface of the photoconductor 10 as shown in FIG. 3D, and is charged by electrostatic force. The toner is moved onto the photoconductor 10 to form a toner image.

Next, the transfer device 60 transfers the toner image formed on the photoconductor 10 to a recording medium such as paper. As shown in FIG. 3E, the toner image formed on the photoconductor 10 and the corona-released paper are conveyed by the paper feeding device 610 and fed between the photoconductor 10 and the transfer belt 602. The toner adheres to the surface by the electrostatic force generated between the transfer belt 602 and the transfer belt 602 which is charged with an electric charge having an opposite polarity to the toner by the electric device 606. As a result, the photoconductor 1
The toner image formed on No. 0 is transferred to paper. Then, as shown in FIG. 3F, the fixing roller 6 of the fixing device 620.
The transferred toner is thermally melted and fixed by the fixing heater 624 provided in the unit 22. On the other hand, the liquid developer 508 remaining on the photoconductor 10 is removed by the cleaning device 70.
Removed by. It should be noted that the photoconductor 10 is repeatedly used in the above cycle from the charging to the static elimination after the static eliminator 80 eliminates static electricity.

6 to 10 are views for explaining the developing process of the first embodiment of the present invention in detail, FIG. 6 is a diagram for explaining the whole developing process, and FIG. 7 is a drawing for the approaching process. FIG. 8 is a diagram showing a state of the toner movement process, FIG. 8 is a diagram showing a state of the toner movement process, FIG. 9 is a diagram showing a separation process of the non-image portion, and FIG. 10 is a diagram showing a separation process of the image portion. Unlike the conventional developing process, in the developing process of the first embodiment, as shown in FIG. 6, the developing belt approaches the photoconductor and the liquid developer approaches the photoconductor surface, and the liquid developer layer. And a prewetting liquid layer are in soft contact with each other to move the toner, and a separation process in which the developing belt is separated from the photoconductor and separated into toner adhering to the developing belt and toner adhering to the photoconductor. It is thought to consist of three processes.

In the approaching process, the developing belt 510 is made of a flexible member as shown in FIG.
A minute gap d between the developing belt 510 and the photoconductor 10
Is formed, and the high-viscosity liquid developer including the carrier liquid and the toner is soft-contacted with the pre-wet liquid.
As a result, the pre-wet liquid having a low viscosity is slightly pushed back and forth, and a liquid pool of the pre-wet liquid is generated.

In the toner moving process, as shown in FIG. 8, in the image portion, the toner passes through the pre-wet liquid layer mainly due to the Coulomb force due to the electric field formed between the charge on the photoconductor 10 and the developing belt 510. And move to the latent image surface. On the other hand, the toner in the non-image area is basically the photosensitive member 10.
Since the surface of the liquid developer and the liquid developer layer are separated by the pre-wet liquid layer, unnecessary toner does not adhere to the surface of the photoconductor 10.

In the separation process, in the non-image part, as shown in FIG.
Basically, the liquid developer remains on the developing belt 510 as shown in FIG. At the interface between the pre-wet liquid layer and the liquid developer layer, when the two layers are separated, a part of the pre-wet liquid layer having a low viscosity is transferred to the liquid developer layer and separated. Therefore, the separation point of the two layers is considered to be inside the pre-wet liquid layer. On the other hand, in the image area, as shown in FIG. 10, the toner that has moved to the surface of the photoconductor 10 displaces the pre-wet liquid layer, so that the pre-wet liquid layer is located on the toner layer and is separated in that layer. On the developing belt 510, a part of the carrier liquid remaining after the toner is moved and a part of the pre-wetting liquid form a layer. The pre-wetting liquid remaining on the photoconductor 10 facilitates the movement of the toner due to the electrostatic force in the subsequent transfer process.

FIG. 11 is a diagram for explaining the significance of thinning the liquid developer. If the liquid developer layer applied on the developing belt 510 is too thick, the liquid developer 508
Since the viscosity of the toner is high, the toner group that tries to move from the developing belt 510 to the surface of the photoconductor 10 by the electrostatic force forms a cluster with respect to the toner located around the toner group and does not cut off the viscosity. Since it moves to the surface of the toner, excessive adhesion of toner occurs and image noise occurs. In order to suppress the generation of these clusters, it is necessary to control the thickness of the liquid developer layer to a minimum value at which development can be sufficiently performed.

FIG. 12 is a view showing that the developing roller, which is the developing support, and the photosensitive member are in hard contact with each other.
FIG. 13 is a diagram for explaining the soft contact of the first embodiment. As explained above, in the developing process of the first embodiment, the function of the pre-wet liquid layer for image formation is important. Therefore, an important requirement in the developing process is to maintain the two-layer state of the pre-wet liquid layer and the liquid developer layer. As shown in FIG. 12, when the developing roller and the photoconductor are hard-contacted with each other, the two-layer state cannot be maintained. Therefore, in the first embodiment, as shown in FIG. By using the developing belt 510 composed of a member having a small gap d, a minute gap d is formed between the surface of the photoconductor 10 on which the electrostatic latent image is formed and the developing belt 510.

Next, optimization of the layer thickness of the liquid developer layer, the layer thickness of the pre-wet liquid layer and the developing gap will be described. The layer thickness of the liquid developer layer is such that the viscosity of the liquid developer is 50 to 50.
Especially 500m for 100mPa · s or more
It is necessary to reduce the thickness of those having Pa · s or more.
Ideally, it should be slightly thicker than the layer thickness that satisfies the toner development amount (that is, the density when solid black is produced) required at the time of development. This is because when a high-viscosity liquid developer is used, electrostatically selected toner moves onto the photoconductor along with the excess toner due to the viscosity of the liquid during development, causing abnormal toner adhesion. This is because the image is smeared and the image is stained. In an experiment conducted by the inventors, a good image was obtained with a layer thickness of about 5 μm for liquid developers having a high toner concentration and about 40 μm for those having a low toner concentration. When a liquid developer having a toner concentration of 20 to 30% was used, good image quality was obtained when the layer thickness of the liquid developer was about 20 μm.

The layer thickness of the pre-wet liquid layer has an optimum value depending on the viscosity and surface tension of the selected pre-wet liquid. If it is too thin, the high-viscosity liquid developer irregularly adheres to the photoconductor to cause image contamination. As the amount of pre-wetting liquid is increased, image stains are improved,
The optimum value is confirmed. When the amount is further increased, the charge of the latent image flows, the sharpness and the resolution are deteriorated, and the toner flows during development, which also tends to blur the image. D
In the experiment using C344, good results were obtained with a thickness of 5 to 30 μm. For those having a lower viscosity than this, good results can be obtained with a thinner thickness or a thicker thickness. However, for high viscosity ones, the optimum value tends to have a narrow range.

As in the conventional developing method, the narrower the gap between the photosensitive member and the developing belt, the better the resolution and the uniformity of the density of the solid portion in the image quality. The highly viscous liquid developer used in the first embodiment has a strong cohesive force between the toners, so that the toner released from the developer support or carrier particles by mechanical impact or electrostatic force is developed like the powder developer. There is no phenomenon like that used in. That is, development is not performed with an air layer interposed between the liquid developer layer and the photoconductor. Therefore, the developing belt and the liquid developer layer,
It is essential that the liquid developer layer and the pre-wet liquid layer are in contact with each other, and the pre-wet liquid layer and the photoconductor are in contact with each other. Therefore, the development gap d is equal to the liquid developer layer,
The dimensions must be less than the thickness of the pre-wet liquid layer and not disturb the respective layers. In the first embodiment, it is set between 20 μm and 50 μm depending on the viscosity of the liquid developer and the difference in toner concentration.

Table 1 shows the results of the image forming experiment under the above-mentioned conditions. From these results, the optimum range of the developer and the viscosity of the pre-wet liquid for the developing method of the first embodiment is 100 mPa · s to 6000 mPa · s for the developer.
s, pre-wetting liquid is 0.5 mPa · s to 5 mPa · s
It was found to be between s. Regarding image quality,
Although it varies depending on the thickness of the liquid developer layer on the developing belt, the thickness of the pre-wet liquid layer, the development gap, etc., even if the various developing conditions are optimized, there is a general tendency as shown in Table 1. It was confirmed that the optimum area of the liquid developer falls within the range shown in Table 1. The silicone oil of the pre-wet liquid is DC200 series manufactured by Dow Corning, and the carrier liquid of the developing liquid is DC345 of the same company.
Was used.

[0058]

[Table 1]

According to the first embodiment of the present invention, the toner image formed on the latent image surface of the photoconductor 10 is used by using the transfer belt 602 composed of a flexible member for the transfer body. Since it is possible to disperse the contact pressure when the paper and the paper as the recording medium are in contact with each other, it is possible to prevent the toner image from being disturbed, and therefore, the toner image is transferred onto the paper without causing image deletion. be able to.

Further, according to the first embodiment, the transfer belt 6
By setting the electric resistance value of 02 to 10 ⁴ to 10 ¹¹ Ωcm, the toner image formed on the photoconductor 10 can be satisfactorily transferred to the paper.

Further, according to the first embodiment, since the surface of the transfer belt 602 is coated with fluorine, the releasability from the toner is improved, so that the transfer belt 60 is released.
It is possible to easily scrape off the toner adhered to the transfer belt 2 and prevent the transfer belt 602 from being soiled.

In addition, according to the first embodiment, the use of silicon oil as the carrier liquid for the liquid developer has the following advantages over the conventional one.

Conventional liquid developers generally use IsoparG (registered trademark: manufactured by Exxon) as a carrier liquid.
Since this Isopar has a resistance value not as high as that of silicone oil, when the toner concentration is increased, that is, when the distance between particles is reduced, the chargeability of the toner is deteriorated. Therefore, Isop
In the case of ar, the toner density is limited. On the contrary,
Since the silicone oil used in the first embodiment has a sufficiently large resistance value, the toner concentration can be increased. Further, generally, in the case of Isopar, the toner dispersion state is good, and therefore even if the toner concentration is 1 to 2%, the toner particles repel each other, so that the toner particles are uniformly dispersed. On the other hand, when the toner concentration is 1 to 2%, the silicone oil has poor dispersibility and will be precipitated soon. However, when the toner concentration is set to 5 to 40%, the toner is densely packed and stably dispersed. Therefore, in the first embodiment, a high-viscosity liquid developer in which toner is dispersed at high density is used. As a result, compared to the conventional low-concentration liquid developer, the amount of developer can be significantly reduced,
It is possible to reduce the size of the device. Furthermore, since the liquid developer of the first embodiment is a high-viscosity liquid, it is easier to store and handle than the conventional low-viscosity liquid developer or powder developer.

Isopar used in the conventional liquid developer is
As mentioned above, it is highly volatile and emits a foul odor,
There is a problem that it not only deteriorates the work environment but also causes pollution. On the other hand, the silicone oil used in the first example is a safe liquid and is odorless, as is clear from the fact that it is used for cosmetics. , The working environment can be improved and no pollution problem will occur.

In the first embodiment, as a transfer device, a transfer belt 602 is charged on the latent image surface of the photoconductor 10 by charging the transfer belt 602 with a charge having a polarity opposite to that of the toner by a corona discharger 606. Although the transfer of the toner image to the paper has been described, the present invention is not limited to this, and the transfer device may be, for example, an electric resistance value in which conductive fine particles are added to a driving roller that rotationally drives the transfer belt. It is also possible to use a low rubber roller and apply a bias voltage to the driving roller to apply a bias voltage to the transfer belt to transfer the toner image onto the paper. Also,
As shown in FIG. 14, at the transfer point between the photoconductor 10 and the transfer belt 602, a conductive sponge roller 607 is pressed from the back surface of the transfer belt 602 to apply an appropriate pressing force, and the sponge roller 607 is biased. A bias voltage may be applied to the transfer belt 602 by applying a voltage to transfer the toner image onto the paper.

In the first embodiment, as the developing device,
Although the developing belt 510 formed of a flexible member is used as the developer support, the present invention is not limited to this, and the developing device may include a metal or the like on the developer support. Alternatively, a developing roller formed of the conductive member may be used. However, in order to bring the liquid developer layer formed on the developing roller and the pre-wet liquid layer formed on the photoconductor into contact with each other while maintaining the two-layer state, and to separate the both inside the pre-wet liquid layer. It is necessary to use a flexible member for the image support or to dispose the developing roller so as to form a minute gap d between the developing roller and the photosensitive member.

Next, a second embodiment of the present invention will be described with reference to FIG.
Will be described with reference to. FIG. 15 is a schematic configuration diagram of an image forming apparatus according to the second embodiment of the present invention. Incidentally, in the electrostatic latent image liquid developing apparatus shown in FIG. 15, those having the same functions as those in the first embodiment are designated by the same reference numerals or corresponding reference numerals, and detailed description thereof will be omitted. .

Image forming apparatus 2 according to the second embodiment of the present invention
15 is different from that of the first embodiment, as shown in FIG. 15, in place of the photoconductor 10 which is an image support, the photosensitive belt 1
2 is used, and the drive rollers 122a, 122b, 12
It is held by 2c and rotationally driven, the developing device 52 is used in place of the developing device 50, and the transfer device 64 is used in place of the transfer device 60.

As the base material of the photosensitive belt 12, a flexible member such as a seamless nickel belt, a resin belt or a polyimide film belt is used. This allows
The contact pressure when the toner image formed on the photosensitive belt 12 comes into contact with the paper can be dispersed.

The developing device 52 of the second embodiment differs from the developing device 52 of the first embodiment in that a developing roller 520 is used instead of the developing belt 510 which is a developer support. The developing roller 520 rotates in the direction opposite to the rotation direction of the photosensitive belt 12 to convey the liquid developer 508 applied to the surface of the photoconductor 10 by the applying roller 506. The developing roller 520, the conductive rubber roller so as to be able to apply the developing bias (10 ⁴ to 1
A member having conductivity such as 0 ¹¹ Ωcm) is used.

The transfer device 64 of the second embodiment is different from the developing device 60 of the first embodiment in that the transfer belt 6 as a transfer member is used.
02, a transfer roller 642 is used, and
Instead of the corona discharger 606 that charges the transfer belt 602 with an electric charge having a polarity opposite to that of the toner, a power supply device (not shown) that applies a bias voltage to the transfer roller 642 is provided.

The transfer roller 642 rotates in the direction opposite to the rotation direction of the photosensitive belt 12 so that the paper feeding device 6
The paper conveyed by 10 is fed between the photosensitive belt 12 and the transfer roller 642. For the transfer roller 642, a conductive member such as a metal is used so that a bias voltage can be applied. The electric resistance value of the transfer roller 642 is 10 ⁴ to 1
0 ¹¹ Ωcm is desirable. If the electric resistance value is 10 ⁴ Ωcm or less, the resistance value of the paper varies considerably depending on the type of paper and the humidity (10 ⁹ to 10 ¹³ Ωcm), so that the fluctuation of the resistance value of the paper is formed on the photosensitive belt 12. It is not appropriate because it affects the transfer of toner image to paper. Electric resistance value is 10 ¹¹ Ω
If it is at least cm, the transfer roller 642 and the photosensitive belt 12
The electrostatic force between the toner image formed above and the toner image weakens, and the toner is not sufficiently moved to the paper.

The surface of the transfer roller 642 is coated with fluorine. This is to improve the releasability with respect to the toner and to easily scrape the toner adhering to the transfer roller 642 by the scraping blade 608 to prevent the transfer roller 642 from being soiled.

In the transfer device 64 having the above structure, the paper conveyed by the paper feeding device 610 and fed between the photosensitive belt 12 and the transfer roller 642 is supplied by the toner image formed on the photosensitive belt 12 and the power supply device. The electrostatic force generated between the toner and the transfer roller 642 to which the bias voltage is applied causes the toner to move onto the paper, and the toner image formed on the photosensitive belt 12 is transferred onto the paper. The other operations of the electrostatic latent image liquid developing device according to the second embodiment are the same as those of the first embodiment, and thus detailed description thereof will be omitted.

According to the second embodiment of the present invention, the toner formed on the latent image surface of the photosensitive belt 12 is used by using the photosensitive belt 12 composed of a flexible member for the image support. Since it is possible to disperse the contact pressure when the image and the paper as the recording medium come into contact with each other, it is possible to prevent the toner image from being disturbed as in the case of the first embodiment. The image can be transferred without causing image deletion. Other effects are similar to those of the first embodiment.

Next, FIG. 16 shows the third embodiment of the present invention.
Will be described with reference to. FIG. 16 is a schematic configuration diagram of an image forming apparatus according to the third embodiment of the present invention. In the image forming apparatus of the third embodiment, those having the same functions as those of the first embodiment are designated by the same reference numerals or corresponding reference numerals, and detailed description thereof will be omitted.

The image forming apparatus 3 according to the third embodiment is different from that according to the first embodiment in that the photosensitive member 10 as an image support is used.
The photosensitive belt 12 used in the apparatus of the second embodiment is used instead of the drive roller 122a, 1 like the second embodiment.
22b and 122c hold and rotate. The operation of the image forming apparatus according to the third embodiment is the same as that of the first embodiment, and detailed description thereof will be omitted.

According to the third embodiment of the present invention, the photosensitive belt 12 made of a flexible member is used as the image support, and the transfer made of a flexible member is used as the transfer body. By using the belt 602, the photosensitive belt 12
Since it is possible to disperse the contact pressure when the toner image formed on the latent image surface of the paper and the paper that is the recording medium come into contact with each other, the toner image can be satisfactorily transferred to the paper without causing image deletion You can Other effects are similar to those of the first embodiment.

The present invention is not limited to the above embodiments, but various modifications can be made within the scope of the invention. For example, in each of the above-described embodiments, the pre-wetting device, which applies the pre-wetting liquid 220 to the surface of the photoconductor 10 by the pre-wetting liquid supply member 202, has been described, but the present invention is not limited to this. Instead, the pre-wetting device may be one that can apply a constant amount of the pre-wetting liquid to the surface of the photoconductor uniformly. For example, it may be applied by ejecting the pre-wet liquid from a plurality of nozzles arranged in the axial direction, or applied by a sponge roller or the like.

In each of the above embodiments, the exposure device 40
The image was exposed on the image support charged by the above, and then the pre-wetting device 20 was used to apply the pre-wet liquid 220 on the image support, but the present invention is not limited to this. Prewetting device 20
By applying the pre-wetting liquid 220 on the image support,
After that, the image may be exposed on the image support charged by the exposure device 40.

Furthermore, in each of the above-mentioned embodiments, the case where the organic photoconductor is used as the image support has been described, but the present invention is not limited to this, and the image support is
It may be an electrostatic recording paper such as an electrostatic plotter, or an electrophotographic recording medium in which an insulating layer is formed on a conductor that directly forms an electrostatic latent image such as various photoconductors used in the Carlson method or ionography.

The present invention is not limited to the above-mentioned embodiments, and a pre-wet liquid layer is formed, and
If the layer thickness of the liquid developer is 5 to 40 μm, the viscosity of the high viscosity developer may be 10,000 mPa · s. At present, a developer with a high viscosity of 6000 mPa · s or more is difficult to agitate between the carrier liquid and the toner, so it is thought to be costly. However, if it becomes available at a low cost, it will be even at 6000 mPa · s or more. Good. Viscosity 100
Those exceeding 00 mPa · s become unrealistic.

[0083]

As described above, according to the first aspect of the present invention, by virtue of the above configuration, when the toner image formed on the latent image surface of the image support comes into contact with the recording medium. Since the contact pressure of the toner can be dispersed, it is possible to prevent the toner image from being disturbed, and therefore, the toner image can be transferred to the recording medium without causing image deletion, and the toner has a high density. By developing the high-viscosity liquid developer dispersed in a thin layer to develop, it is possible to provide an image forming method which has a high resolution, can be easily downsized, and can reduce pollution.

According to the second aspect of the invention, the transfer member has an electric resistance value of 10 ⁴ to 10 ¹¹ Ωcm, and in addition to the effect of the first aspect of the invention, it is formed on the image support. It is possible to provide an image forming method capable of favorably transferring the toner image to a recording medium.

According to the third aspect of the present invention, since the surface of the transfer member is coated with fluorine, the releasability from the toner is improved, so that the toner attached to the transfer member can be easily scraped off. In addition to the effect of the invention described in claim 1, it is possible to provide an image forming method capable of preventing the transfer body from being soiled.

According to the invention described in claim 4, by virtue of the above-mentioned constitution, in addition to the effect of the invention described in claim 1, there is provided an image forming method in which the liquid developer and the pre-wet liquid are well compatible with each other. can do.

According to the fifth aspect of the invention, by virtue of the above-mentioned constitution, in addition to the effect of the fourth aspect of the invention, there is provided an image forming method capable of improving the working environment with less pollution. Can be provided.

According to the sixth aspect of the invention, by virtue of the above-mentioned constitution, in addition to the above effects, it is possible to provide an image forming method in which the toner is easily peeled off during transfer.

According to the seventh aspect of the invention, by virtue of the above construction, it is possible to provide an image forming method capable of improving the releasability at the time of transfer in addition to the above effects. .

According to the invention as set forth in claim 8, by virtue of the above-mentioned constitution, in addition to the above effects, there is provided an image forming method which can further reduce the pollution and improve the working environment. it can.

According to the ninth aspect of the invention, with the above configuration, it is possible to provide an image forming apparatus having the same effect as the effect of the first aspect of the invention.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an image forming apparatus that is a first embodiment of the present invention.

FIG. 2 is a schematic perspective view of a pre-wetting device used in the image forming apparatus shown in FIG.

FIG. 3 is a diagram for explaining the operation of the image forming apparatus shown in FIG.

FIG. 4 is a diagram for explaining the operation of the pre-wetting device shown in FIG.

FIG. 5 is a diagram showing the flow of the pre-wet liquid when the pre-wet liquid supply member is brought into contact with the photoconductor.

FIG. 6 is a diagram for explaining the entire developing process.

FIG. 7 is a diagram showing a state of an approaching process.

FIG. 8 is a diagram showing a state of a toner movement process.

FIG. 9 is a diagram showing a separation process of a non-image portion.

FIG. 10 is a diagram showing a process of separating an image portion.

FIG. 11 is a diagram for explaining the significance of thinning the liquid developer.

FIG. 12 is a diagram showing a state in which a developing roller and a photoconductor are in hard contact.

FIG. 13 is a diagram for explaining soft contacts of the image forming apparatus according to the first embodiment.

FIG. 14 is a diagram showing a modification of the transfer device used in the image forming apparatus according to the first embodiment.

FIG. 15 is a schematic configuration diagram of an image forming apparatus that is a second embodiment of the present invention.

FIG. 16 is a schematic configuration diagram of an image forming apparatus that is a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Photoconductor 12 Photosensitive belt 20 Pre-wet device 30 Charging device 40 Exposure device 50,52 Developing device 60,64 Transfer device 70 Cleaning device 80 Eliminating device 122a, 122b, 122c, 512a, 512b,
512c, 604a, 604b, 604c Drive roller 202 Pre-wet liquid supply member 204 Case 206, 502 Tank 208 Pump 210a, 210b Tube 212 Displacement device 220 Pre-wet liquid 502a Release roller 504 Supply roller 506 Application roller 508 Liquid developer 510 Development belt 520 Developing roller 602 Transfer belt 607 Sponge roller 610 Paper feeding device 620 Fixing device 622 Fixing roller 624 Fixing heater 642 Transfer roller

Claims (9)

[Claims] 1. An electrostatic latent image formed on an image support,
An image forming method of developing with a toner which is a charged image-forming particle, and transferring a toner image formed on the image support to a recording medium, which comprises: A pre-wetting process of applying a pre-wetting liquid, which is a dielectric liquid having releasability and chemically inert, and 100 to 1 in which the toner is dispersed at a high concentration in the insulating liquid.
A developing step of supplying a high-viscosity liquid developer of 0000 mPa · s to the latent image surface of the image support by a developer support; and supplying the high-viscosity liquid developer to the latent image surface of the image support. And a transfer step of transferring the toner image formed by the transfer to a recording medium arranged on the transfer body, wherein at least one of the image support and the transfer body is formed of a flexible member. An image forming method, characterized in that 2. The transfer member has an electrical resistance value of 10 ⁴ to 1
The image forming method according to claim 1, wherein the image forming method is 0 ¹¹ Ωcm. 3. The image forming method according to claim 1, wherein the transfer member has a surface coated with fluorine. 4. The liquid developer, wherein the insulating liquid has a viscosity of 0.5 to 1000 mPa · s and an electric resistance of 10 ¹² Ωcm.
Above, surface tension is 21 dyne / cm or less and boiling point is 10.
4. The temperature is 0 ° C. or higher, claim 1, 2 or 3.
The image forming method described. 5. The image forming method according to claim 4, wherein the liquid developer uses silicon oil as an insulating liquid. 6. The liquid developer has an average particle diameter of 0.1 to 5
The image forming method according to claim 1, 2, 3, 4, or 5, wherein the toner contains a toner having a particle size of 5 μm at a concentration of 5 to 40%. 7. The pre-wetting liquid has a viscosity of 0.5 to
5 mPa · s, electric resistance 10 ¹² Ωcm or more, boiling point 1
The image forming method according to claim 1, 2, 3, 4, 5 or 6, wherein the surface tension is 0 to 250 ° C and the surface tension is 21 dyne / cm or less. 8. The image forming method according to claim 7, wherein the pre-wetting liquid contains silicon oil as a main component. 9. An electrostatic latent image formed on an image support,
An image forming apparatus which develops with a toner which is a charged image-forming particle and transfers the toner image formed on the image support to a recording medium, which has releasability on the image support. Prewetting means for applying a prewetting liquid, which is a chemically inert dielectric liquid, and 100 to 1 in which the toner is dispersed at a high concentration in the insulating liquid.
Developing means for supplying a high-viscosity liquid developer of 0000 mPa · s to the latent image surface of the image support by a developer support, and supplying the high-viscosity liquid developer for the latent image surface of the image support. And a transfer unit configured to transfer the toner image formed by the transfer to a recording medium arranged on the transfer body, and at least one of the image support and the transfer body is formed of a flexible member. An image forming apparatus characterized in that