JP2001305886A - Liquid development electrophotographic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent heat deterioration of a photoreceptor drum by isolating the heat which transfers to the photoreceptor drum. SOLUTION: An intermediate transfer assembly includes an intermediate transfer roller being arranged so as to transform a toner image held on an image holding body according to electric field formed between the image holding body and the intermediate transfer roller, and an intermediate transfer belt or roller where the toner image transferred onto the intermediate transfer roller is further transferred and the toner image further transferred is melt and transferred onto a printing medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid developing electrophotographic apparatus using a liquid toner, and more particularly to a liquid developing apparatus in which heat of a heated intermediate transfer belt is prevented from being transmitted to a photosensitive drum via an intermediate transfer roller. The present invention relates to an electrophotographic apparatus.

[0002]

2. Description of the Related Art In an electrophotographic apparatus in which an electrostatic latent image is formed on a photosensitive member (photosensitive drum), toner is adhered to the image, and the image is transferred to paper and fixed, a dry type using powder toner is widely used. Used. However, the powder toner has a problem that the toner is scattered and a problem that the resolution is poor because the toner particles are as large as 7 to 10 μm.

Therefore, when high resolution is required, a liquid developing system using a liquid toner is used. This is because the liquid toner has toner particles as small as about 1 μm and the charge amount is large, so that disturbance of the toner image hardly occurs and high resolution can be realized.

FIG. 7 shows the overall structure of a conventionally known liquid developing type electrophotographic apparatus (for example, Japanese Patent Laid-Open No. 2000-2000).
-56575). After being charged by the charging device 21, the photosensitive drum 10 is exposed by the exposure device 22 to form an electrostatic latent image. The pre-wet device 23 applies silicone oil to the surface of the photosensitive drum 10.

The developing device 24 is provided in association with yellow / magenta / cyan / black, and uses a non-volatile, high-viscosity, high-concentration liquid toner as a liquid developing solution. The developing roller supplies the liquid developing solution onto the photosensitive drum 10 and causes toner particles of the liquid developing solution to adhere to the photosensitive drum 10 according to an electric field generated between the developing roller and the photosensitive drum 10.

The intermediate transfer roller 15 transfers the color toner attached to the photosensitive drum 10 one by one according to the electric field between the intermediate transfer roller 15 and the photosensitive drum 10. When the intermediate transfer roller 15 transfers the toner particles adhered to the photosensitive drum 10 in accordance with the electric field between the intermediate transfer roller 15 and the photosensitive drum 10, excessive pre-wet and development that move from the photosensitive drum 10 to the intermediate transfer roller 15 together with the toner particles It is necessary to remove the oil consisting of the carrier in the toner layer. Therefore, in the illustrated apparatus, an oil removing roller 25 is provided on the intermediate transfer roller 15.

The heating device 28 heats the surface of the intermediate transfer roller 15 to melt the toner attached to the intermediate transfer roller 15. The heating by the heating device 28 is performed after transferring the toners of all colors. The pressure roller 19 fixes the toner on the intermediate transfer roller 15 melted by the heating device 28 to the print medium. In the figure, reference numeral 26 denotes a blade for scraping off residual developing toner, and 27 denotes a static eliminator.

Since the color toners adhered to the photosensitive drum 10 are transferred one by one, the toner on the intermediate transfer roller 15 which has already been transferred is contacted between the photosensitive drum 10 and the intermediate transfer roller 15 before heating. Passing through the part. At this time, the excess pre-wet liquid and the carrier accumulate there when they are conveyed to the contact portion between the photosensitive drum 10 and the intermediate transfer roller 15, flow and disturb the image, or cause the toner layer to be heated and melted during fixing. Affect.

The configuration shown can remove such excess pre-wet liquid or carrier liquid. However, in this configuration, the photosensitive drum 10 and the intermediate transfer roller 1
It is necessary that the heat is sufficiently cooled at the contact portion with the heat sink 5. Due to the heat resistance of the photosensitive drum 10, the temperature is 60 ° C.
It must be: For this reason, when the printing speed is increased, there is a problem that the cooling device becomes large as well as the heating device.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to prevent heat deterioration of the photosensitive drum by interrupting heat transfer to the photosensitive drum.

Another object of the present invention is to efficiently heat and cool without substantially lowering the throughput.

[0012]

A liquid developing electrophotographic apparatus according to the present invention uses a liquid toner as a liquid developing solution and supplies the liquid developing solution by contacting an image support on which an electrostatic latent image is formed. And a developing unit for forming a toner image by adhering toner particles of the liquid developer to the image support in accordance with an electric field generated between the image support and the developing unit. An intermediate transfer unit for transferring the toner image, and a transfer fixing unit that heats and melts the toner image transferred to the intermediate transfer unit at a contact portion with the print medium and melt-transfers the toner image to the print medium. The intermediate transfer unit, according to an electric field between the image support, an intermediate transfer roller for transferring a toner image on the image support, the toner image transferred to the intermediate transfer roller is further transferred, and And an intermediate transfer belt on which the transferred toner image is melt-transferred onto a print medium.

Further, the liquid developing electrophotographic apparatus of the present invention comprises:
The intermediate transfer unit includes a first intermediate transfer member for transferring a toner image on the image support according to an electric field between the image support and a toner image transferred to the first intermediate transfer member. Further, the image forming apparatus is characterized by comprising a second intermediate transfer body which is transferred and the transferred toner image is melt-transferred to a print medium.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail according to embodiments. FIG. 1 is a diagram showing a first configuration example of a liquid developing type electrophotographic apparatus embodying the present invention.
In the present invention, a non-volatile, high-viscosity, high-concentration liquid toner is used as a liquid developer. The liquid toner is obtained by dispersing solid particles such as a pigment in a liquid carrier (oil). It is.

The illustrated liquid developing electrophotographic apparatus includes a developing section provided at the lowermost portion of the apparatus, an intermediate transfer section above the developing section,
And a transfer / fixing unit located at the top of the apparatus. The developing units are provided in association with yellow / magenta / cyan / black. One photosensitive drum (photoconductor) 10 is provided, and a charger for charging the photosensitive drum 10 to about 700 V is provided. In addition, a static eliminator (not shown) is provided in front of the charger, and a photosensitive drum 10 is provided.
The above residual potential is eliminated. The exposure indicated by the arrow is performed by charging the charged photosensitive drum 10 based on image data, for example, 780
This is performed using laser light having a wavelength of nm. As a result, the potential of the exposed portion on the photosensitive drum 10 becomes about 100
An electrostatic latent image which is V is formed. A pre-wet device is provided at a position after exposure and before development. The pre-wet apparatus uses a conventionally known technique, and has a cst of 2.5 cSt to 500 cSt.
4-5 μm of silicone oil having a viscosity of about cSt
The thickness can be applied to the surface of the photosensitive drum 10.

The developing section includes one developing belt common to each color, a toner supply roller provided in association with yellow / magenta / cyan / black for supplying and applying a liquid toner onto the developing belt, and a developing unit. It comprises a blade for each color for scraping off toner remaining on the developing belt later. The toner supply roller and the toner scraping blade are respectively arranged horizontally below the developing belt. The toner supply roller is generally composed of a plurality of rollers for each color toner, and has a toner viscosity of 100 to 40.
00mPa · S, carrier viscosity 20 ~ 500cS
The liquid toner having a predetermined layer thickness (for example, 4 to 10 μm) is applied to the developing belt by pumping the liquid toner having preferably 100 cSt from the toner reservoir (toner tank) and conveying the liquid toner while spreading it thinly. I do. A roller that contacts the toner tank and adjusts the toner supply amount can be configured by a gravure roller (patterned roller). By arranging the developing unit at the lower part in this way, even if toner leaks, it becomes possible to prevent the inside of the apparatus from being stained.

The developing belt is biased at a predetermined voltage such as about 400 V to 600 V, and supplies the positively charged toner to the photosensitive drum 10 in accordance with an electric field between the developing belt and the photosensitive belt 10. As a result, toner is attached to an exposed portion on the photosensitive drum 10 charged to about 100 V, and the electrostatic latent image on the photosensitive drum 10 is developed to form an image.

Intermediate transfer roller 1 as first intermediate transfer member
5 are biased to about -800 V, and each photosensitive drum 1
The toner adhered to the photosensitive drum 10 is transferred according to an electric field between 0 and 0. The intermediate transfer roller 15 first transfers a toner image developed using a first color, for example, a yellow liquid toner, and then develops using a second color, for example, a magenta liquid toner. Transferred toner image, followed by transferring a toner image developed using a third color, for example, cyan liquid toner, and finally,
A toner image developed using a fourth color, for example, black liquid toner is transferred. In this manner, the first to fourth four-color toner images are sequentially superimposed on the intermediate transfer roller 15 by rotating the intermediate transfer roller 15 four times to form a color image. A carrier removing roller is provided on the intermediate transfer roller 15, and after all of the four color toners are superimposed on the intermediate transfer roller, the carrier can be brought into contact with the intermediate transfer roller to remove excess carrier and pre-wet liquid.

Thereafter, the four-color image is electrostatically transferred onto an intermediate transfer belt 16 having a belt structure as a second intermediate transfer member. Then, after the carrier liquid is removed by the carrier removing unit, the toner image on the intermediate transfer belt 16 is heated and melted by the fixing heat roller, and the printing medium is contacted with the printing medium conveyed on the medium conveying belt. Is melt-transferred.

After the four color toner images superimposed on the intermediate transfer roller are simultaneously transferred to the intermediate transfer belt, the four color toner images are transferred to the intermediate transfer belt 15 while the next print image is formed on the intermediate transfer roller 15. Can be lowered, and by lowering the rotation speed, the temperature of the fixing heater can be set low.

Further, instead of superimposing the four-color toner image on the intermediate transfer roller 15 as described above, the four-color toner image is sequentially transferred from the photosensitive drum 10 to the intermediate transfer roller 1.
5, the toner image is transferred to the intermediate transfer belt 16 one by one, and toner images of four colors are superimposed on the intermediate transfer belt 16. At this time, the respective circumferential lengths of the photosensitive drum 10 and the intermediate transfer roller 15 are
One image is completed by two rotations of the photosensitive drum 10 and the intermediate transfer roller 15 by making the perimeter shorter than the vertical length of the image area, for example, making each circumference half of the vertical length of the image area. Can be configured. As a result, the size of the device can be reduced.

The intermediate transfer belt is formed on the polyimide by 5 to
An elastic layer can be provided on the roller surface by coating with 50 μm silicon rubber or fluorosilicone rubber. With such an elastic layer, the toner image can be melt-transferred to high quality paper or the like having a relatively rough surface by reliably pressing the toner image at the nip portion with the print medium. The image formed of the liquid toner on the intermediate transfer belt 16 contains a carrier liquid, and the carrier oil removed by the carrier removing unit illustrated as having a plurality of rollers is removed. This carrier removal section
It is provided at an appropriate position between the contact portion of the intermediate transfer belt 16 with the intermediate transfer roller 15 and the time until the toner image on the intermediate transfer belt is heated and melted.

This carrier removal can be performed after the four color toner images are transferred onto the intermediate transfer belt and before the next print image is formed on the intermediate transfer roller. The carrier removing device is evacuated while the toner image is being transferred onto the intermediate transfer belt 16 and while the toner image passes through the fixing heat roller, and after the toner image is heated and melted by the fixing heat roller, the toner cools down. The carrier can be removed only when the carrier is in a hardened state.

The print medium is conveyed, for example, on an electrostatic attraction belt which is attracted and conveyed by electrostatic force, and the toner image on the intermediate transfer belt 16 is melt-transferred and fixed at the transfer and fixing unit. This electrostatic attraction belt can include a retraction mechanism that makes contact with the intermediate transfer belt only when transfer to a print medium is performed in the transfer and fixing unit.

The heating by the fixing heat roller is for melting the toner image on the intermediate transfer belt 16 and performing the transfer and fixing to the print medium. Later, it needs to be cooled. This is performed at a position after contact with the print medium and before contact with the intermediate transfer roller, and can be performed, for example, by using a roller around which the intermediate transfer belt 16 is wound as a cooling roller. . The cooling roller may be provided with fins therein, and may be cooled by blowing air. The cooling is performed to prevent heat from being transmitted to the photosensitive drum and causing the photosensitive drum to thermally degrade.

The intermediate transfer belt has a thickness of 5 to 50 μm.
By setting m to be small, the heat capacity can be reduced so that the sheet is heated at the contact portion with the print medium and then naturally cooled.

Further, means for cooling not only the intermediate transfer belt but also the intermediate transfer roller can be provided. This can be performed by providing a fin inside the intermediate transfer roller and blowing air to the fin using, for example, a fan.

As described above, since the liquid developing electrophotographic apparatus shown in the drawing is provided with the transfer fixing section which generates a large amount of heat at the top of the apparatus, heat can be efficiently exhausted from the apparatus. Further, the cooling of the intermediate transfer belt 16 can be made more efficient. Further, since the developing section for handling the liquid toner is provided at the lowermost portion of the apparatus, even if the liquid toner leaks, the printing medium is hardly stained.

The configuration shown in FIG.
6 and the intermediate transfer roller 15 are separated from each other except when the toner image is transferred. This can be performed by a mechanism for retracting the intermediate transfer belt. This makes it possible to block the transfer of heat from the intermediate transfer belt 16 to the intermediate transfer roller 15 and from there to the photosensitive drum 10. After the transfer to the intermediate transfer belt 16, the heating temperature of the intermediate transfer belt 16 can be reduced by reducing the rotation speed of the intermediate transfer belt 16 to ま で.

FIG. 2 is a diagram showing a second configuration example of a liquid developing type electrophotographic apparatus embodying the present invention. In the illustrated liquid developing electrophotographic apparatus, an intermediate transfer section is provided below a developing section provided at the top of the apparatus, and a transfer fixing section for transferring and fixing to a print medium is provided below the intermediate transfer section. As an intermediate transfer section, two intermediate transfer members of primary and secondary roller configurations are provided. As described above, since the transfer is performed from one roller to another, stable contact can be ensured, and the nip pressure between both rollers can be easily increased.

It is desirable that the material of the secondary intermediate transfer body has a surface layer and a lower layer, and that the surface layer has a higher resistance than the lower layer. Thereby, the current flowing in the surface direction of the secondary intermediate transfer member can be suppressed. At the time of the electrostatic secondary transfer, the toner is prevented from scattering toward the surface, and the edge of the image becomes sharper.

As the material of the primary intermediate transfer member, an elastic rubber material can be used for the lower layer. By using an elastic rubber material, the adhesiveness between the primary intermediate transfer member and the secondary intermediate transfer member is increased, and uniform transfer can be achieved without contact unevenness between the two.

It is desirable that the primary and secondary intermediate transfer material should have a lower resistance than the resistance of the toner itself.
FIG. 5 is a diagram for explaining this. At the time of the electrostatic secondary transfer, the bias voltage V is applied to the primary intermediate transfer member and the secondary intermediate transfer member with the toner layer interposed therebetween. This is modeled and shown on the left side of FIG. 5, and its equivalent circuit is shown on the right side. By reducing the resistance R1 of the primary intermediate transfer member and the resistance R2 of the secondary intermediate transfer member, the voltage Vt applied to the toner layer is increased,
The electric field E applied to the toner layer can be increased.

It is desirable to use a material having a high dielectric constant in the lower layer of the primary and secondary intermediate transfer material. A material having a high dielectric constant has a large capacitance, and flows more current in an operating state than in a stationary state. By using a material having a low resistance value and using a material having a high dielectric constant, current can flow more easily, and the resistance appears to be lower in an operating state.

It is desirable to use a primary and secondary intermediate transfer material having a mirror surface with little unevenness. FIG.
It is a figure for explaining this. The model on the left side of FIG. 6 models a state where the surface of the intermediate transfer member has irregularities. The middle part of FIG. 6 shows a state in which the toner layer has been transferred onto the irregularities. When the toner layer is transferred to the next transfer medium, as shown in the right side of FIG. 6, irregularities appear on the surface of the toner layer. In order to improve the quality of image printing, it is desirable that the surface of the intermediate transfer member should be as smooth as possible.

FIG. 3 is a diagram showing a third configuration example of a liquid developing type electrophotographic apparatus embodying the present invention. The illustrated liquid developing electrophotographic apparatus also has two intermediate transfer members, primary and secondary, as intermediate transfer units. As in the apparatus illustrated in FIG. 1, the primary intermediate transfer member is constituted by a roller, and the secondary intermediate transfer member is constituted by a belt. By configuring the transfer from the roller to the belt, the nip width is increased, and the transfer time can be increased. By increasing the transfer time, the transfer efficiency can be increased.

FIG. 4 is a diagram showing a fourth configuration example of a liquid developing type electrophotographic apparatus embodying the present invention. The illustrated liquid developing electrophotographic apparatus has the same structure as the apparatus illustrated in FIG. 3 except that the primary intermediate transfer member of the intermediate transfer unit is configured by a roller, and the secondary intermediate transfer body is configured by a belt. A roller is applied. Thereby, the stability of contact between the primary transfer roller and the secondary transfer belt can be increased.

[0038]

The present invention has a mechanism for separating the primary and secondary intermediate transfer members except when the toner image is transferred from the primary intermediate transfer member to the secondary intermediate transfer member. The heat of the heated secondary intermediate transfer member is transmitted to the photosensitive drum via the primary intermediate transfer member, thereby preventing the photosensitive drum from being thermally degraded. In addition, this enables efficient heating and cooling without lowering the substantial throughput.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first configuration example of a liquid developing type electrophotographic apparatus embodying the present invention.

FIG. 2 is a diagram showing a second configuration example of a liquid developing type electrophotographic apparatus embodying the present invention.

FIG. 3 is a diagram illustrating a third configuration example of a liquid developing type electrophotographic apparatus embodying the present invention.

FIG. 4 is a diagram illustrating a fourth configuration example of a liquid developing type electrophotographic apparatus embodying the present invention.

FIG. 5 is a diagram illustrating a low resistance that the intermediate transfer material should have.

FIG. 6 is a diagram for explaining the function of the intermediate transfer material.

FIG. 7 is a view showing the overall configuration of a conventionally known liquid developing type electrophotographic apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Photosensitive drum 15 Intermediate transfer roller 16 Intermediate transfer belt 21 Charging device 22 Exposure device 23 Pre-wet device 24 Developing device 26 Blade 27 Static elimination device 28 Heating device

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/10 G03G 15/10 2H074 15/11 15/20 103 3J103 15/20 103 109 109 109 15/10 113 21/20 21/00 534 (72) Inventor Shigenori Uesugi 98 Unoki-nu, Unoki-cho, Hebei-gun, Ishikawa Pref. Inside PFU Co., Ltd. (72) Inventor Satoru Hongo Unoki 98, Unoki-cho, Kawakita-gun, Ishikawa Address No. 2 PFU Co., Ltd. (72) Inventor Masanori Takahata 98 Uno-ki, Unoki-cho, Hebei-gun, Ishikawa Prefecture 98-2 In Pfu Co., Ltd. (72) Inventor Genji Ichida Unoki-nu, Unoki-cho, Kawakita-gun, Ishikawa 98-2 PFU Co., Ltd. (72) Inventor Shigeharu Okano 98 shares of Unoki, Unoki-cho, Kawakita-gun, Ishikawa Pref. (72) Inventor, Keiichi Takeda, Unoki-cho, Unoki-cho, Kawakita-gun, Ishikawa Prefecture 98 (2) Inventor, Satoshi Nishikawa 98, Unoki-nu, Unoki-cho, Kawakita-gun, Ishikawa, Japan 2 PFU Co., Ltd. (72) Inventor, Satoshi Miyamoto 98, Unoki-nu, Unoki-cho, Kawakita-gun, Ishikawa Prefecture 2 P-fu Co., Ltd. (72) Kazushi Terashima, 98, Unoki-nu, Unoki-cho, Kawakita-gun, Ishikawa 2 PFU Co., Ltd. (72) Inventor Satoshi Sakai 98, Unoki-nu, Unoki-cho, Hebei-gun, Ishikawa Prefecture 2 PFU-U Co., Ltd. (72) Hironori Motokawa Unogu-98, Unoki-cho, Kawakita-gun, Ishikawa Prefecture No. 2 Inside PFU Co., Ltd. (72) Inventor Masanobu Motoe 98 Unoki Nu, Unoki-cho, Hebei-gun, Ishikawa Prefecture F-term within PFU Corporation (reference) 2H027 JA11 JB13 JB16 JC01 JC09 2H030 AA06 AD04 BB02 BB27 BB42 BB46 BB61 2H032 AA05 AA14 BA0 4 BA08 BA09 BA21 BA30 CA04 CA13 2H033 AA02 AA41 BB04 BB15 CA04 CA07 CA27 CA36 2H071 DA08 DA09 EA04 EA18 2H074 AA03 AA04 BB50 CC22 3J103 FA01 GA02 GA52 HA11

Claims (25)

[Claims] 1. A liquid developer is used as a liquid developer to supply a liquid developer in contact with an image support on which an electrostatic latent image is to be formed and to be generated between the image support and the image developer. A developing unit for forming a toner image by attaching toner particles of the liquid developer to the image support in response to an electric field; an intermediate transfer unit for transferring the toner image on the image support; A transfer fixing unit that heats and melts the toner image transferred to the printing unit at a contact portion with the print medium and melt-transfers the toner image to the print medium, wherein the intermediate transfer unit includes the image support An intermediate transfer roller for transferring a toner image on the image support in accordance with an electric field between the intermediate transfer roller and the toner image transferred to the intermediate transfer roller, and further transferring the transferred toner image to a print medium. Is melt-transferred to And an intermediate transfer belt. And a mechanism for separating the intermediate transfer roller and the intermediate transfer belt except when a toner image is transferred from the intermediate transfer roller to the intermediate transfer belt. 2. The liquid developing electrophotographic apparatus according to claim 1, wherein transmission to the image support via an intermediate transfer roller is prevented. 3. A means for cooling the intermediate transfer belt at a position after contact with a print medium and before contact with the intermediate transfer roller, and means for cooling the intermediate transfer roller. Item 3. A liquid development electrophotographic apparatus according to Item 2. 4. The liquid developing electrophotographic apparatus according to claim 3, wherein cooling of the intermediate transfer roller is performed by providing fins inside the intermediate transfer roller and blowing air. 5. The intermediate transfer belt has a thickness of 5 to 50 μm.
The liquid developing electrophotographic apparatus according to claim 2, wherein the heat capacity is reduced to heat the portion in contact with the print medium and then cool naturally. 6. A fixing heat roller for heating and fusing the toner image on the intermediate transfer belt, wherein the fixing heat roller and the intermediate transfer belt are provided with an elastic layer on their surfaces to form a nip portion with a print medium. 6. The liquid developing electrophotographic apparatus according to claim 5, wherein the toner image can be reliably transferred to a high-quality paper having a relatively rough surface by pressing the toner image. 7. The image support is constituted by a photosensitive drum, and toner images of each color are sequentially transferred from the photosensitive drum to an intermediate transfer roller and from there to an intermediate transfer belt. 3. The liquid development electrophotography according to claim 2, wherein the apparatus is miniaturized by making the peripheral lengths of the photosensitive drum and the intermediate transfer roller shorter than the vertical length of the image area. apparatus. 8. The image support is constituted by a photosensitive drum, and toner images of respective colors are sequentially transferred from the photosensitive drum to an intermediate transfer roller, and a plurality of color toner images superimposed on the intermediate transfer roller are converted into a plurality of color toner images. 3. The liquid developing electrophotographic apparatus according to claim 2, wherein the image is transferred to an intermediate transfer belt at the same time to reduce the influence of color expansion accuracy due to thermal expansion. 9. The liquid developing electrophotographic apparatus according to claim 2, wherein the separation of the intermediate transfer roller and the intermediate transfer belt is performed by retracting the intermediate transfer belt. 10. After a plurality of color toner images superimposed on the intermediate transfer roller are simultaneously transferred to an intermediate transfer belt, a plurality of color toner images are transferred to the intermediate transfer roller while a next print image is formed on the intermediate transfer roller. 9. The liquid developing electrophotographic apparatus according to claim 8, wherein the rotation speed of the transfer belt is reduced and the temperature of the fixing heater is set low. 11. A method in which a plurality of color toner images superimposed on the intermediate transfer roller are simultaneously transferred to the intermediate transfer belt in a plurality of colors, and then the toner images on the intermediate transfer belt are heated and melted. The liquid developing electrophotographic apparatus according to claim 8, further comprising a carrier removing device. 12. The image forming apparatus according to claim 1, wherein after the plurality of color toner images have been transferred onto the intermediate transfer belt, the carrier removing device is configured to move the toner image on the intermediate transfer belt until a next print image is formed on the intermediate transfer roller. The liquid developing electrophotographic apparatus according to claim 11, wherein the toner image is heated to remove the carrier liquid. 13. The carrier removing device according to claim 1, wherein the toner image is transferred onto the intermediate transfer belt and evacuated while passing through the fixing heat roller. Then, the toner image is heated and melted by the fixing heat roller, and the toner is cooled. The liquid developing electrophotographic apparatus according to claim 12, wherein the carrier is removed by contacting the solidified state. 14. The image forming apparatus according to claim 8, further comprising a carrier removing device on the intermediate transfer roller, wherein the carrier removing device makes contact with the intermediate transfer roller after all of the plurality of color toners are superimposed on each other. The liquid developing electrophotographic apparatus according to claim 1. 15. An electrostatic attraction belt for transporting a print medium, wherein the electrostatic attraction belt has a retraction mechanism for making contact with the intermediate transfer belt only when transfer to a print medium is performed in the transfer and fixing section. The liquid developing electrophotographic apparatus according to claim 2, further comprising: 16. The image forming apparatus according to claim 1, wherein the developing unit is provided at a lower portion of the apparatus, and the intermediate transfer belt is provided at an upper part of the apparatus so as to efficiently heat the inside of the apparatus and prevent the image support and the developing section from being affected by heat. The liquid developing electrophotographic apparatus according to claim 2, which is configured. 17. A developing device comprising: a developing belt in contact with a photosensitive drum serving as the image support; and a toner applying mechanism arranged in a horizontal direction for applying a plurality of color toners to a lower portion of the developing belt. And a toner scraping mechanism provided for each of the toners of a plurality of colors in order to collect the residual toner on the developing belt after the development, so as to prevent contamination in the apparatus due to leakage of the toner. Claim 1
7. The liquid developing electrophotographic apparatus according to 6. 18. The liquid developing device according to claim 17, wherein the toner application mechanism includes a toner tank that pumps up from a lower portion of the mechanism, and a roller that contacts the toner tank and adjusts a toner supply amount is a gravure roller. Photo equipment. 19. The liquid developing electrophotographic apparatus according to claim 1, wherein a rigid roller is applied from the back side of said intermediate transfer belt to contact said intermediate transfer roller. 20. The liquid developing electrophotographic apparatus according to claim 1, wherein the intermediate transfer belt has a two-layer structure including a surface layer and a layer below the surface layer, and the surface layer is formed of a material having higher resistance than the lower layer. . 21. The liquid developing electrophotographic apparatus according to claim 1, wherein said intermediate transfer roller uses an elastic rubber material for a lower layer. 22. A liquid developer as a liquid developer,
A liquid developer is supplied in contact with an image support on which an electrostatic latent image is to be formed, and toner particles of the liquid developer are applied to the image according to an electric field generated between the image support and the image support. A developing unit for forming a toner image by adhering to a support, an intermediate transfer unit for transferring the toner image on the image support,
A liquid fixing electrophotographic apparatus comprising: a transfer fixing unit that heats and fuses the toner image transferred to the intermediate transfer unit at a contact portion with a print medium and melt-transfers the toner image to the print medium; A first intermediate transfer roller for transferring a toner image on the image support in accordance with an electric field between the image support and the toner image transferred to the first intermediate transfer roller; A liquid developing electrophotographic apparatus comprising a second intermediate transfer roller for transferring the transferred toner image to a print medium by fusion transfer. 23. The liquid developing electrophotographic apparatus according to claim 1, wherein a material having a low resistance is used as a material of a roller or a belt constituting the intermediate transfer section. 24. The liquid developing electrophotographic apparatus according to claim 1, wherein a material having a high dielectric constant is used as a lower layer material of a roller or a belt constituting the intermediate transfer section. 25. The liquid developing electrophotographic apparatus according to claim 1, wherein a material surface of a roller or a belt constituting the intermediate transfer portion is a mirror surface having little unevenness.