JP2003345138A - Liquid developing electrophotographic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure paper separation with a relatively low pressure of a current of air, in the fusion transfer part of a liquid developing electrophotographic device using a liquid toner. <P>SOLUTION: In paper separation in the fusion transfer part, the fusio transfer part is constituted of an image support having an elastic surface, and a rotary body which faces the image support and has a surface having hardness greater than that of the image support. By constituting the fusion transfer part, with the leading end of a printing medium directed to the rotary body, air is blown to the surface of the rotary body so that the direction in which air blows is substantially vertical to a straight line passing through a nip, the air flows toward the nip on the printing-medium exit side, and the printing medium is separated from the rotary body. <P>COPYRIGHT: (C)2004,JPO

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, it uses air to reliably separate paper at a relatively small wind pressure in the paper separation in a melt transfer section, and to melt the paper. A liquid-developing electrophotographic apparatus capable of non-contactly transporting a print medium to a fixing unit so that a paper guide is not contaminated or an image is deteriorated when the print medium separated by a transfer unit is transported to the fixing unit. Is.

[0002]

2. Description of the Related Art FIG. 9 is a block diagram of a liquid developing electrophotographic apparatus using liquid toner. In FIG.
After being charged by the charger 54, the exposure device 53
Is exposed to form an electrostatic latent image. Developing device 5
2 is provided in association with yellow / magenta / cyan / black, and uses a non-volatile, high-viscosity, high-concentration liquid toner as a liquid developer. The developing roller contacts the photoconductor 51 to supply the liquid developer, and adheres the toner particles of the liquid developer to the photoconductor 51 according to the electric field generated between the developing roller and the photoconductor 51.

The supply of this liquid developer to the developing roller is
It is carried out by the developing solution applying means while being thinly extended from the toner reservoir, whereby a toner layer having a thickness of about 2 to 3 μm is formed on the developing roller. Incidentally, 56 is a blade for scraping off the residual toner, and 55 is a static eliminator.

The intermediate transfer member 57 is generally about -300V.
Biased to, and following the electric field between the photoconductor 51,
The toner attached to the photoconductor 51 is, for example, yellow /
By transferring in the order of magenta / cyan / black, a four-color image is formed on the intermediate transfer member 57 in a superimposed manner. In addition, 4 formed on the intermediate transfer member 57.
The carrier liquid removing device 59 removes the carrier liquid from the color image.

The backup roller 60 is an intermediate transfer member 5.
7, the backup roller 60 and the intermediate transfer body 57 constitute a melt transfer section, the melt transfer section is pressed, and the color image formed on the intermediate transfer body 57 is transported from the transport roller 64. Melt transfer to the print medium. The intermediate transfer member 57 and the backup roller 60 are
A heater 58 and a heater 61 are provided respectively, and the surfaces of the intermediate transfer body 57 and the backup roller 60 are heated to a predetermined temperature.

The melt-transferred print medium 62 is conveyed to a fixing unit 63 which is heated to a predetermined temperature by a heater and subjected to a fixing process. A paper guide 65 for guiding the print medium 62 is provided between the fusion transfer section and the fixing unit 63.

By the way, in the separation of the print medium in the fusion transfer section constituted by the backup roller 60 and the intermediate transfer member 57, the toner in the molten state has a melt viscosity of the toner (in the molten state, the toner exhibits a strong adhesive force, The print medium 62 may be wound around the intermediate transfer body 57 or the backup roller 60 due to the property of sticking to the print medium or the intermediate transfer body) and the pressure applied during the melt transfer. Therefore, the intermediate transfer member 57 or the backup roller 6
It is necessary to separate the print medium 62 wound around 0 from the intermediate transfer body 57 or the backup roller 60.

FIG. 10 shows a diagram of the prior art.
In the figure, the backup roller 60 and the intermediate transfer member 5
When the print medium 62 is separated in the melt transfer section constituted by the backup roller 60 and the intermediate transfer member 57.
A separating claw 70 is provided on the outlet side of the printing medium 62, and the printing medium 62 wound around the intermediate transfer member 57 or the backup roller 60 is made to collide with the separating claw 70 to separate the winding printing medium 62.

FIGS. 11 and 12 show other prior art drawings. In the figure, the backup roller 60
When separating the print medium by separating the print medium 62 from the intermediate transfer body 57 or the backup roller 60 in the separation of the print medium in the fusion transfer portion constituted by the intermediate transfer body 57 and the intermediate transfer body 57, for example, FIG. As shown in (a), air is blown from the side of the intermediate transfer member 57 to the nip portion of the melt transfer portion. Alternatively, as shown in FIG. 12A, air is blown from the backup roller 60 side to the nip portion of the melt transfer portion. The air is shown in FIG.
As shown in (b), the print medium 62 is evenly sprayed in the width direction.

The air blown to the nip portion of the melt transfer portion is blown obliquely to the nip portion. Therefore, as shown in FIG. 12 (b), the wind pressure F of the air is at the backup roller surface or It consists of a component force Fa for pressing the surface of the intermediate transfer member and a component force Fb for pressing the print medium 62. For this reason, the air pressure F of air is increased in the sheet separation at the fusion transfer section.

[0011]

As described above, the conventional techniques have the following problems.

When a separating claw is used in the sheet separation in the melt transfer section, the toner adheres to the separating claw to cause toner stain on the separating claw, and the toner stain accumulates to adhere the toner to the print medium. To do. Further, the contact between the surface of the intermediate transfer body and the surface of the backup roller and the separation claw may cause the surface of the intermediate transfer body and the surface of the backup roller to be damaged.

Further, when air is used in the sheet separation in the melt transfer section, the air is blown obliquely to the nip portion, and the wind pressure of the air is the component force for pressing the surface of the rotary member and the printing. It consists of the component force to press the medium. Therefore, it is necessary to increase the air pressure of the air during the sheet separation in the melt transfer section.

Further, in the liquid development electrophotographic apparatus shown in FIG. 9, the physical contact between the paper path such as a paper guide and the print medium increases the frictional force for transporting the print medium to the fixing portion, and the melt transfer is performed. In addition to the feeding force of the printing medium in the set, a feeding force for conveying the printing medium to the fixing unit is required.

Further, in the liquid developing electrophotographic apparatus shown in FIG. 9, by disposing the developing section on the lower side of the apparatus,
Even if the liquid toner leaks, the print medium and the intermediate transfer member are not contaminated. Further, although there is an advantage that the influence of heat on the photoconductor can be prevented, the image surface may be below the surface after the melt transfer, so that the paper guide may be stained and the image may be deteriorated.

An object of the present invention is to reliably perform sheet separation with a relatively small wind pressure by using air in the sheet separation in the melt transfer section of the liquid developing electrophotographic apparatus using the liquid toner.

Further, when the print medium separated by the melt transfer section is conveyed to the fixing section, the air used for separating the sheet is also used so that the sheet guide is not contaminated or the image is deteriorated. The purpose is to convey the print medium to the fixing unit by contact.

[0018]

In order to solve the above problems, the present invention employs the following means.

In the sheet separation in the melt transfer section, the melt transfer section is composed of an image support having a surface having elasticity and a rotating body facing the image support and having a surface having a hardness higher than that of the image support. In a state in which the tip of the print medium is directed to the rotating body side, the air is blown onto the surface of the rotating body so that the air blowing direction is substantially perpendicular to the straight line passing through the nip portion, and the air is printed. The print medium is separated from the rotating body side by being configured to face the nip portion on the outlet side.

By taking the above-mentioned means, the air blown onto the surface of the rotating body is diffused in the width direction of the printing medium while heading for the nip portion on the print medium outlet side along the surface of the rotating body. Further, the air blown on the surface of the rotating body goes to the nip portion without applying the component force for pressing the surface of the rotating body. As a result, in the sheet separation in the fusion transfer section, the sheet separation is surely performed with a relatively small wind pressure.

Further, when the print medium separated in the melt transfer section is conveyed to the fixing section, air is blown up in the direction of pushing up the separated print medium from the rotator side, and the air to be blown up and the air blown onto the surface of the rotator. With this configuration, the print medium is conveyed to the fixing unit in a non-contact manner.

By adopting the above means, in the paper path between the melt transfer section and the fixing section, the air blown up and the air blown onto the surface of the rotating body prevent abnormal lifting of the print medium, By reducing the frictional force for transporting the medium to the fixing unit, it becomes possible to transport the print medium to the fixing unit without using a special physical transport means. Further, even if there is an unfixed image on the lower side of the print medium, image deterioration does not occur.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention has the following embodiments.

As shown in FIG. 1 and FIG. 2, the liquid developing electrophotographic apparatus is such that an intermediate transfer member 1 as an image support formed of a material whose surface has elasticity and an intermediate transfer member 1 facing each other. A fusion transfer section is constituted by a backup roller 2 as a rotating body whose surface has a hardness higher than that of the intermediate transfer body 1, and the intermediate transfer body at the nip portion generated at the time of pressurization in the melt transfer section. The melt viscosity of the toner and the tack of the surface of the intermediate transfer body 1 are utilized by utilizing the depressions of No. 1 (the surface of the intermediate transfer body is made of rubber so that the surface of the intermediate transfer body has elasticity so that the print medium sticks to the surface of the rubber, etc. The property prevents the print medium 12 from being wound around the intermediate transfer body 1 and causes the front end of the print medium 12 to move toward the backup roller 2.
A liquid developing electrophotographic apparatus using a liquid toner provided with a paper separating mechanism configured to blow air in a direction of separating the print medium 12 from the backup roller 2 side in a state of being directed toward the side. The mechanism has at least one air outlet 8 for blowing air,
The position where the air is blown out is above the radius of the backup roller 2 as viewed from the nip portion and is perpendicular to the straight line a passing through the nip portion and the tangent line to the outlet side of the print medium 12 of the backup roller 2. On the surface of the backup roller 2, the range between the straight line b passing through the center of the backup roller 2 and the direction in which the air is blown out is substantially perpendicular to the straight line a passing through the nip portion. Configure to spray.

By adopting the above-mentioned form, the air blown onto the surface of the rotating body in such a manner that the air is blown out in a direction substantially perpendicular to the straight line passing through the nip portion, and the air blown onto the surface of the rotating body is blown. Spread toward the nip portion on the print medium outlet side along the surface of the rotating body and diffuse in the width direction of the print medium. Further, the air blown on the surface of the rotating body goes to the nip portion without applying the component force for pressing the surface of the rotating body. As a result, in the sheet separation in the melt transfer section, the sheet separation is surely performed with a relatively small wind pressure.

Further, the paper separating mechanism is provided with an air pressure / air volume adjusting mechanism 6, and the air pressure / air volume adjusting mechanism 6 applies an air pressure of 0.15 MPa (1.5 kgf / cm) to the surface of the backup roller 2. ² ) and above,
Set the air volume to 20 liters / min or more.

By adopting the above-mentioned form, the sheet separation in the fusion transfer section can be made more stable and reliable.

Further, the paper separating mechanism reduces the air pressure of the air blown onto the surface of the backup roller 2 to 0.
The air flow rate is set to 15 MPa (1.5 kgf / cm ² ) or more, and the air flow rate is changed according to the paper thickness of the print medium.
Set to 0 liter / min, thicker than 45 kg / ream 1
The air volume is set to 15 liters / min for print media thinner than 20 kg / ream, and the air volume is set to 5 liters / min for print media over 120 kg / ream.

By adopting the above-mentioned form, the air flow rate is appropriately changed with respect to the paper thickness of the print medium, so that the paper separation in the melt transfer section becomes efficient.

Further, the paper separating mechanism is provided with a hot air generating mechanism 7, and the hot air generating mechanism 7 sets the temperature of the air blown on the surface of the backup roller 2 to be equal to or higher than the temperature set for the backup roller 2.

By adopting the above-mentioned form, the toner in the molten state does not cool rapidly, and the toner image transferred to the image support does not stick. This allows
Since the print medium does not stick to the surface of the image support together with the toner, the paper is reliably separated.

Further, as shown in FIG. 7, the liquid developing electrophotographic apparatus is provided with a blower mechanism 5 for blowing air in a direction of pushing up the print medium 12 separated from the backup roller 2 side by the paper separating mechanism, By the air blown up in the direction of pushing up the print medium 12 and the air blown on the surface of the backup roller 2,
The print medium 12 is configured to be conveyed to the fixing unit 20 in a non-contact manner.

According to the above-mentioned configuration, in the paper path between the melt transfer section and the fixing section, the air blown up in the direction of pushing up the print medium and the air blown on the surface of the rotating body cause the abnormal floating of the print medium. And the physical contact with a print medium such as a paper guide is eliminated, so that the frictional force for transporting the print medium to the fixing unit is reduced. Further, by setting the distance between the melt transfer section and the fixing section shorter than the length of the print medium, without using a special physical transport means,
The print medium can be conveyed to the fixing unit only by the feeding force of the print medium in the melt transfer unit. Further, even if there is an unfixed image on the lower side of the print medium, the image can be conveyed to the fixing unit in a non-contact manner, so that the image is not deteriorated.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A typical embodiment according to the present invention will be described with reference to FIGS. In the following, the same parts are denoted by the same reference numerals, and detailed description thereof may be omitted.

1 and 2 show an embodiment of the present invention.

In the figure, in the melt transfer section of a liquid developing electrophotographic apparatus using a liquid toner, the intermediate transfer member 1 as an image support has a surface made of an elastic material such as rubber. The melt transfer section is constituted by the backup roller 2 as a rotating body which is formed so as to face the intermediate transfer body 1 and have a surface having a hardness higher than that of the intermediate transfer body 1.

The liquid developing electrophotographic apparatus utilizes the depression of the intermediate transfer member 1 at the nip portion generated at the time of pressurization in the melt transfer portion, and by the melt viscosity of the toner and the tack on the surface of the intermediate transfer member 1, The print medium 12 is prevented from being wound around the intermediate transfer body 1, and air is blown onto the surface of the backup roller 2 with the tip of the print medium 12 facing the backup roller 2 side. 12 is separated from the backup roller 2 side.

The air outlet 8 for blowing out air has a small-diameter through hole and is provided at the center of the backup roller 2 in the width direction. Further, as shown in FIG. 2, the position where the air is blown out is above the radius of the backup roller 2 as seen from the nip portion and is perpendicular to the straight line a passing through the nip portion. It is set within a range between a tangent line of the print medium 12 on the outlet side and a straight line b passing through the center of the backup roller 2.

The air is blown out in a direction substantially perpendicular to the straight line a passing through the nip portion, and air is supplied to the air blow-out port 8 by the blower mechanism 5 including an air pump or the like, so that the backup is performed. Spray on the surface of the roller 2.

The air pressure / air volume adjusting mechanism 6 has a function of appropriately adjusting the air pressure and the air volume of the air blown onto the surface of the backup roller 2. In addition, the hot air generating mechanism 7
Is provided with a heater heated to a high temperature and blows air by the blowing mechanism 5 to generate hot air, which is supplied to the air outlet 8 and blown onto the surface of the backup roller 2.

As shown in FIG. 3, the backup roller 2
The air blown onto the surface of the backup roller 2 from the central portion in the width direction of the print head travels along the surface of the backup roller 2 toward the nip portion on the print medium outlet side,
Diffuses in the width direction of the print medium 12. Furthermore, since the air blown onto the surface of the backup roller 2 goes to the nip portion without applying the component force for pressing the surface of the backup roller 2, as in the conventional case, the air is blown obliquely to the nip portion. Compared with the case of spraying, the paper can be sufficiently separated with a small wind pressure.

In FIG. 4, when the melt transfer pressure, the melt transfer temperature, and the wind pressure are the same, the sheet is straight from the melt transfer section when the air blowing position and the air blowing direction are changed. The experimental results of the probability of appearing in are shown.
In the air blowing direction, the case where the air is blown onto the surface of the backup roller 2 in a direction substantially perpendicular to the straight line passing through the nip portion is A, and air is blown toward the nip portion from an oblique direction with respect to the straight line passing through the nip portion. When attaching B
C represents the case where air is blown from a substantially horizontal direction toward the nip portion with respect to a straight line passing through the nip portion.

As shown in FIG. 4 (b), in the case where the air is blown onto the surface of the backup roller 2 in a direction substantially perpendicular to the straight line passing through the nip portion,
The probability that the paper will come out straight from the melt transfer section is 10
It turns out that it is the highest with 0%. That is, when compared with other blowing positions and blowing directions, it is shown that the paper separation is reliably performed even with a relatively small wind pressure (0.15 MPa).

Next, the backup roller 2 is set so that the air blowing direction is substantially perpendicular to the straight line passing through the nip portion.
The experimental result when changing the wind pressure and the air volume when spraying on the surface of is shown.

FIG. 5 shows the experimental results of the probability that the paper will come out straight from the melt transfer section when the wind pressure is changed under the same conditions of the melt transfer pressure and the melt transfer temperature. As shown in FIG. 5B, it can be seen that if the air pressure is set to 0.15 MPa or more, the probability that the paper will come out straight from the melt transfer section becomes 100%.

FIG. 6 shows that when the melt transfer pressure, the melt transfer temperature, and the wind pressure are set to the same conditions and the air volume is changed with respect to the paper thickness of the print medium, the paper straightly comes out from the melt transfer section. The experimental result of the probability of coming is shown. As shown in FIG. 6B, the wind pressure is set to 0.15 MPa (1.5 kgf / c).
m ² ), the air pressure at which the probability that the paper will come out straight from the melt transfer section is 100% is 45 liters / repeated printing medium, and the air volume is 20 liters / min or more. In the medium, the air volume is 15 liters /
The air flow rate is 5 liters / min or more for a printing medium of 120 kg / ream.

In FIG. 5 and FIG. 6, in order to more stably and reliably separate the paper in the melt transfer portion, the air pressure of the air blown onto the surface of the backup roller 2 is set to 0.
It can be seen that it is desirable to set the pressure to 15 MPa (1.5 kgf / cm ² ) or more and the air flow rate to 20 liters / min or more.

Further, in FIG. 6, by changing the air volume with respect to the paper thickness of the printing medium, in order to efficiently perform the paper separation in the melt transfer section, the air pressure of the air blown on the surface of the backup roller 2 is changed. 0.15 MPa (1.
5 kgf / cm ² ) or more, and an air flow rate of 20 liters / min for print media of 45 kg / ream or less.
Is set to 15 liters / min for print media thicker than 45 kg / ream and less than 120 kg / ream, and set to 5 liters / min for print media over 120 kg / ream. It turns out that it is desirable.

The diameter of the backup roller 2 is 100.
If it exceeds mm, the distance from the air outlet to the nip becomes too large, and the electrostatic force generated at the nip causes the print medium to stick to the backup roller 2 facing the intermediate transfer body 1 more than the air. Since it is superior, it is difficult to separate the paper.

By the way, when the print medium 12 receives a low temperature air to lower its temperature, the toner image transferred to the intermediate transfer body 1 is fixed due to rapid cooling of the molten toner. Wake up. Along with this, the print medium 12 also sticks to the surface of the intermediate transfer body 1 together with the toner. Therefore, in order to prevent the occurrence of such a phenomenon and ensure the paper separation, the temperature of the air blown onto the surface of the backup roller 2 is set to, for example, the melt transfer temperature set in the backup roller 2. (Melting temperature of resin component of toner particles) or higher.

FIG. 7 shows another embodiment of the present invention.

In the figure, as shown in FIG. 1 described above, in order to separate the sheets in the fusion transfer section, the air blowing direction is set to be substantially perpendicular to the straight line passing through the nip portion, and the backup roller 2 is rotated. The liquid developing electrophotographic apparatus having a mechanism for spraying on the surface is provided with a blower mechanism 5 for blowing air in a direction to push up the print medium separated from the backup roller 2 side.

The air is blown up in a direction substantially perpendicular to the straight line a (see FIG. 2) passing through the nip portion, and is blown onto the image surface side of the print medium emerging from the melt transfer portion. The air outlet that blows out the air
It is desirable that the through holes having a small diameter are formed and provided in the entire width direction of the intermediate transfer body 1 as shown in FIG. 8, so that the intermediate transfer body 1 is uniformly blown up in the width direction of the print medium 12.

The air pressure / air volume adjusting mechanism 6 is provided on the image surface side of the print medium in response to the air pressure and the air volume of the air blown on the surface of the backup roller 2 described above with reference to FIG. It has a function of appropriately adjusting the air pressure and the air volume of the air to be blown.

The print medium 12 is contactlessly fixed by the air blown up in the direction of pushing up the print medium and the air blown onto the surface of the backup roller 2.
It can be configured to transport to zero.

As a result, the fusion transfer section and the fixing unit 2
If the distance between the melt transfer portion and the fixing unit is set to be shorter than the length of the print medium in the paper path between the print medium and 0, abnormal rise of the print medium can be prevented and the print medium in the melt transfer portion can be prevented. The printing medium can be conveyed to the fixing unit 20 in a non-contact manner only by the feeding force. Also,
Even if there is an unfixed image on the lower side of the print medium, it can be conveyed to the fixing unit 20 in a non-contact manner, so that image deterioration does not occur.

[0057]

According to the present invention, the following effects can be expected.

An image support having an elastic surface and a rotating body having a surface facing the image support and having a hardness higher than that of the image support constitute a melt transfer section, and the front end of the print medium is formed. In the state in which the air is blown toward the rotating body side, a paper separating mechanism for blowing the air onto the surface of the rotating body is configured so that the air blowing direction is substantially perpendicular to the straight line passing through the nip portion. The air blown onto the surface is directed to the nip portion on the print medium outlet side along the surface of the rotating body and is diffused in the width direction of the print medium. Further, the air blown on the surface of the rotating body goes to the nip portion without applying the component force for pressing the surface of the rotating body.
As a result, it is possible to reliably perform the sheet separation with a relatively small wind pressure in the sheet separation at the fusion transfer unit.

Further, by providing an air pressure / air volume adjusting mechanism, the sheet separation in the fusion transfer section can be made more stable and reliable. Further, by appropriately changing the air volume with respect to the paper thickness of the print medium, the paper separation in the melt transfer section is made efficient.

Further, by providing a hot air generating mechanism and making the temperature of the air equal to or higher than the temperature set for the rotating body, the toner in the molten state is not cooled rapidly, and the toner image transferred to the image support is not. Will not stick. As a result, the print medium does not stick to the surface of the image support together with the toner, so that the paper is reliably separated.

Further, the print medium is conveyed to the fixing unit in a non-contact manner by the air blown up in the direction to push up the print medium and the air blown onto the surface of the rotating body, whereby the melt transfer unit and the fixing unit are arranged. By setting the distance between the melt transfer section and the fixing section to be shorter than the length of the print medium in the paper path between the print medium and the print medium, abnormal lifting of the print medium is prevented, and a special physical conveyance means is provided. Without using, the print medium can be conveyed to the fixing unit only by the feeding force of the print medium in the fusion transfer unit. Further, even if there is an unfixed image on the lower side of the print medium, it can be conveyed to the fixing unit in a non-contact manner, so that the image deterioration can be prevented.

[Brief description of drawings]

FIG. 1 is a diagram of an embodiment of the present invention.

FIG. 2 is a diagram of an embodiment of the present invention.

FIG. 3 is a diagram of an embodiment of the present invention.

FIG. 4 is a diagram of an embodiment of the present invention.

FIG. 5 is a diagram of an embodiment of the present invention.

FIG. 6 is a diagram of an embodiment of the present invention.

FIG. 7 is a diagram of an embodiment of the present invention.

FIG. 8 is a diagram of an embodiment of the present invention.

FIG. 9 is a configuration diagram of a liquid development electrophotographic apparatus.

FIG. 10 is a diagram of the prior art.

FIG. 11 is a diagram of the prior art.

FIG. 12 is a diagram of the prior art.

[Explanation of symbols]

1: Intermediate transfer body 2: Backup roller 5: Blower mechanism 6: Air pressure / air volume adjustment mechanism 7: Hot air generation mechanism 8: Air outlet

Claims (5)

[Claims] 1. Melt transfer with an image support whose surface is formed of a material having elasticity, and a rotating body which is opposed to the image support and whose surface has a higher hardness than that of the image support. The print medium is wound around the image support by the melt viscosity of the toner and the tack on the surface of the image support by utilizing the depression of the image support in the nip portion that occurs when the pressure is applied in the melt transfer section. A liquid using a liquid toner, which is equipped with a paper separating mechanism configured to prevent sticking and blow air in a direction of separating the print medium from the rotating body side with the front end of the print medium facing the rotating body side. In the developing electrophotographic apparatus, the paper separating mechanism has at least one air outlet for blowing air, and the air blowing position is above the radius of the rotating body when viewed from the nip portion, In the range between the tangent line on the print medium outlet side of the rotating body which is perpendicular to the straight line passing through the nip portion and the straight line passing through the center of the rotating body, the air blowing direction is the nip. A liquid developing electrophotographic apparatus, characterized in that the liquid developing electrophotographic apparatus is configured so as to be sprayed onto the surface of the rotating body in a direction substantially perpendicular to a straight line passing through the section. 2. The paper separating mechanism applies a wind pressure of the air blown to the surface of the rotating body of 0.15.
The liquid developing electrophotographic apparatus according to claim 1, wherein the pressure is set to MPa or more and the air volume is set to 20 liter / min or more. 3. The paper separating mechanism applies an air pressure of 0.15 to the surface of the rotating body.
It is configured to change the air flow rate according to the paper thickness of the print medium after setting it to MPa or more, and set the air flow rate to 20 liters / min for the print medium of 45 kg / reach or less, The air volume is set to 15 liters / min for a thick print medium thinner than 120 kg / ream, and the air volume is set to 5 liters / min for a print medium over 120 kg / ream. 1. The liquid developing electrophotographic apparatus according to 1. 4. The liquid developing electrophotographic apparatus according to claim 1, wherein the paper separating mechanism sets the temperature of the air blown onto the surface of the rotating body to be equal to or higher than the temperature set for the rotating body. 5. The liquid developing electrophotographic apparatus comprises an air blowing mechanism that blows air in a direction of pushing up the print medium separated from the rotator side by the paper separating mechanism, and the air blown in the direction of pushing up the print medium and the rotation. The liquid developing electrophotographic apparatus according to claim 1, wherein the print medium is conveyed to the fixing unit in a non-contact manner by air blown onto the surface of the body.