JP2003195643A - Liquid development electrophotographic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid development electrophotographic device which realizes the efficient removal of a carrier solvent remaining in a toner image by removing and recovering the carrier solvent separating in a fixing process step while positively separating the carrier solvent remaining before the fixing process step in a liquid development electrophotographic device using a liquid toner of a high viscosity and high concentration indicating non-volatility. <P>SOLUTION: The liquid development electrophotographic device using the liquid toner of the high viscosity and high concentration indicating the non- volatility is provided with a carrier remover touching an image surface side heating element in a transfer fixing section consisting of the image surface side heating element for heat melting the toner image in a contact section with a printing medium and melt transferring the toner image to the printing medium and a printing medium pressurizer for pressurizing the printing medium in a process for fixing the toner image on the printing medium and is equipped with a carrier removing unit for impressing an electric bias for moving the offset toner to the carrier remover side. <P>COPYRIGHT: (C)2003,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 non-volatile, high-viscosity, high-concentration liquid toner, and particularly to positively separating a carrier solvent remaining before the fixing step. The present invention relates to a liquid developing electrophotographic apparatus that realizes removal and recovery of a carrier solvent separated in a fixing step.

[0002]

2. Description of the Related Art A carrier solvent for liquid development is 1 μm.
It has the function of preventing the toner particles from flying around the air, which is around m, and also has the function of charging the toner particles to make them uniformly dispersed. In the development and electrostatic transfer processes, the toner particles easily move due to the electric field effect. It plays a role like a "bridge" for doing.

The carrier solvent in the liquid development printer process is a necessary component for toner storage, toner transport / layer formation, development and electrostatic transfer. However, the carrier solvent is not required from the viewpoint of image quality after the fixing step on a printing medium such as paper and the fixing step on a non-oil absorbing (non-penetrative) printing medium such as a polyester sheet. For these reasons, volatile insulating liquids are currently used as carrier solvents for many liquid developers (toners).
However, a liquid developer (toner) that uses a non-volatile carrier solvent has also been developed due to toner sticking in the device due to volatilization of the carrier, the influence of the volatile carrier on the human body, environmental issues, etc. High Viscous Silicone-oi
l) Toner.

In the case of a liquid toner using a non-volatile carrier, it is necessary to remove the carrier solvent as much as possible before the fixing step, and the toner image on the intermediate transfer member is removed by the carrier removing step using a carrier removing roller or the like. Carriers are being removed. Further, it has been found that the carrier can be efficiently removed at a temperature (semi-molten state) slightly higher than the Tg temperature (glass transition temperature) of the toner.

However, it is extremely difficult to completely remove the carrier solvent in the toner layer even after such a carrier removing step. The carrier solvent (particularly, silicone oil solvent) inside the toner layer that cannot be completely removed hinders the integration of toner particles (cohesive strength of the toner layer) in the fixing step and the increase in adhesive strength to the print medium. Especially O
Fixing to a polyester sheet, which is a transparent sheet for HP, is because the sheet is non-oil absorbing (non-permeable),
The effect of the residual carrier solvent appears more significantly.

Further, the carrier solvent adhering to the surface of the fixing roller of a general heat pressure roller fixing device must be removed and collected from the fixing roller by the next rotation. This is a method opposite to the release oil application such as silicone oil which is widely used in general dry toner fixing, and is important for the liquid development method using a non-volatile carrier solvent.

FIG. 10 is a prior art diagram showing the overall construction of a liquid developing electrophotographic apparatus. In the figure, the liquid developing electrophotographic apparatus mainly includes a developing unit, an intermediate transfer member 51, a fixing unit 53, and a carrier removing unit. The developing units 54, 55, 56, 57 are
The intermediate transfer member 51 is provided in association with yellow / magenta / cyan / black. Further, each of the developing units 54, 55, 56 and 57 is provided with a photosensitive drum and a developing roller.

The developing roller is biased to a predetermined voltage and adheres toner to an exposed portion on the photosensitive drum in accordance with an electric field between the developing roller and the photosensitive drum to develop an electrostatic latent image on the photosensitive drum to form an image. To form. Liquid toner is supplied to the developing roller from a toner reservoir. As a result, the liquid toner is applied on the developing roller in a predetermined layer thickness.

The intermediate transfer member 51 transfers the toner attached to the photosensitive drums according to the electric field between the intermediate transfer members 51. As a result, the four color toner images developed on the respective photosensitive drums are sequentially superimposed on the intermediate transfer body 51 while the intermediate transfer body 51 is rotated once to form a color image. The carrier liquid is removed by the carrier removing unit from the four-color image superimposed on the intermediate transfer member 51 in this manner.

The image formed by the liquid toner on the intermediate transfer member 51 contains the carrier liquid, and the carrier removing unit for removing the carrier oil is located at the first position after the plural colors are superposed. Carrier removal unit 6
A plurality of carrier removing units including a first carrier removing unit 62, a second carrier removing unit 62, and a third carrier removing unit 63 are arranged, and carriers of, for example, four colors are collectively collected. After that, the four-color image is transferred to the print medium using the pressure roller 52 at the contact portion with the print medium, and then fixed by the fixing unit 53.

As described above, the carrier solvent in the liquid development printer process is used for toner storage, toner transport / layer formation,
It is a necessary component for development and electrostatic transfer. However, the carrier solvent is not required from the viewpoint of image quality after the fixing step on a printing medium such as paper and the fixing step on a non-oil absorbing (non-penetrative) printing medium such as a polyester sheet.

In the case of a liquid developing toner which uses a non-volatile carrier solvent, the carrier solvent cannot volatilize the toner when it is heated and melted. In some cases, the development of adhesive strength is obstructed and the image quality and adhesive strength on the print medium cannot be sufficiently satisfied.

[0013]

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

Even after the carrier removing step as described above,
It is extremely difficult to completely remove the carrier solvent in the toner layer. The carrier solvent (particularly, silicone oil solvent) inside the toner layer that cannot be completely removed is formed by integration of toner particles in the fixing step (cohesion strength of the toner layer),
It prevents the adhesive strength to the print medium from increasing.

Particularly, in fixing to a polyester sheet which is a transparent sheet for OHP, the effect of the residual carrier solvent appears more markedly because the sheet is non-oil absorbing (non-penetrative).

An object of the present invention is to provide HVS (High Viscous Sil
In a liquid development electrophotographic apparatus that uses a high-viscosity, high-concentration liquid toner that exhibits non-volatility (e.g., icone-oil), the carrier that remains in the toner image during the toner image fixing process, especially before the toner image fixing process. It is to remove and collect the separated carrier solvent in the fixing step while positively separating the solvent.

Further, even in the case of a non-oil-absorbing (non-penetrable) printing medium such as a polyester sheet, it is to effectively remove the carrier solvent remaining on the image surface of the printing medium.

[0018]

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

In a liquid developing electrophotographic apparatus using a non-volatile, high-viscosity, high-concentration liquid toner, a toner image is heated and melted at a contact portion with a printing medium, and is fused and transferred to the printing medium. In the process of fixing the toner image on the print medium in the transfer fixing unit that serves as a print medium pressing body that presses the print medium, a carrier removing body that comes into contact with the image surface side heating body is provided, and the carrier removing body side is provided. A carrier removing unit for applying an electric bias for moving the offset toner is provided.

By adopting the above means, in the process of fixing the toner image on the print medium, the high temperature offset toner and surplus carrier solvent which are transferred from the toner image portion and the print medium to the image side heating member are efficiently used. Remove.
That is, instead of simply removing it with a doctor blade, it is removed electrically.

Further, in a liquid developing electrophotographic apparatus that uses a non-volatile, high-viscosity, high-concentration liquid toner, the carrier solvent on the print medium for removing the carrier solvent remaining on the image surface side of the print medium downstream of the fixing unit is removed. The carrier removal unit on a print medium includes a unit, and a carrier removal body that contacts the image surface side of the print medium, and a carrier removal backup body that is installed to face the carrier removal body with the print medium sandwiched therebetween.

By taking the above-mentioned means, in the case of a non-oil absorbing (non-penetrable) print medium such as a polyester sheet, the excess carrier solvent in the image does not penetrate into the print medium, so that it is Although a large amount of surplus oil remains as compared with the print medium, the carrier solvent on the print medium effectively removes the carrier solvent remaining on the image surface of the print medium.

[0023]

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

As shown in FIG. 1, the liquid developing electrophotographic apparatus is a liquid developing electrophotographic apparatus using a non-volatile, high-viscosity and high-concentration liquid toner, and a toner image is heated and melted at a contact portion with a print medium. Then, in the process of fixing the toner image on the print medium in the fixing unit including the image surface side heating body that fixes the print medium and the print medium pressing body that pressurizes the print medium, A carrier removing unit that abuts is provided, and a carrier removing unit that applies an electric bias for moving the offset toner to the carrier removing unit side is provided.

Further, as shown in FIG. 1, the carrier removing member is composed of a conductive or semi-conductive carrier removing roller 21 which is in contact with the image surface side heating member 11 and to which an electric bias is applied.

Further, as shown in FIG. 2, the carrier removing member is composed of a conductive or semi-conductive carrier removing belt 24 which is in contact with the image surface side heating member 11 and to which an electric bias is applied.

Further, as shown in FIG. 3, the carrier removing body is composed of a blade 22 for recovering a conductive or semiconductive carrier solvent which is in contact with the image side heating body 11 and to which an electric bias is applied. To do.

By adopting the above-mentioned form, in the process of fixing the toner image on the print medium, the high temperature offset toner and the surplus carrier solvent which are transferred from the toner image portion and the print medium to the image side heating member are efficiently used. Remove.
That is, instead of simply removing it with a doctor blade, it is removed electrically.

Further, the carrier remover shown in FIGS. 1 to 4 is composed of a member having a resistance value adjusted to a semiconductive range of about 1E4Ω to 1E9Ω. In addition, desirably,
The resistance value of the carrier remover is set in the range of 1E4Ω to 1E7Ω.

By adopting the above-mentioned form, an effective electric field is formed between the carrier removing body and the image surface side heating body.

Further, as shown in FIGS. 1 and 2, in the carrier removing unit, the rotation direction of the carrier removing body is moved in the opposite direction at the contact portion with the image surface side heating body. Rotate (hereinafter sometimes referred to as reverse rotation).

By adopting the above-mentioned form, a high carrier recovery rate can be obtained by rotating the carrier removing member in the reverse direction, so that the carrier recovery efficiency is improved.

Further, in the carrier removing body, the surface material is made of a material having a low friction coefficient.

By adopting the above-mentioned form, excessive rotation load and stick-slip vibration due to the frictional resistance between the image surface side heating body and the carrier removing body are not generated.

Further, as shown in FIG. 4, the carrier removing unit rotates so that the rotation direction of the carrier removing body moves in the forward direction at the contact portion with the image surface side heating body. Hereinafter, it may be referred to as forward rotation), and the rotation speed of the carrier removing body is rotated so that the contact surface moves excessively at the contact portion with the image surface side heating body.

By adopting the above-mentioned embodiment, the carrier removing body is over-fed in the forward rotation to obtain a high carrier recovery rate, so that the carrier recovery efficiency is improved.

Further, as shown in FIGS. 1 to 4, in the liquid developing electrophotographic apparatus, the surface of the image-side heating body 11 is coated with a material that does not swell with a carrier solvent.

By adopting the above-mentioned form, the frictional resistance between the image surface side heating body and the carrier removing body is reduced, so that excessive rotation load and stick-slip vibration are reduced, and the abrasion resistance of the contact member is reduced. Increase.

Further, as shown in FIG. 5, the liquid developing electrophotographic apparatus is a liquid developing electrophotographic apparatus using a non-volatile, high-viscosity and high-concentration liquid toner, and the image surface of the print medium is provided downstream of the fixing unit. A carrier removal unit on the print medium for removing the carrier solvent remaining on the side is provided, and the carrier removal unit on the print medium is a carrier remover that is in contact with the image surface side of the print medium and a carrier remover that sandwiches the print medium. And a carrier-removing backup body installed opposite to each other.

Further, as shown in FIG. 5, the carrier removing body is composed of a conductive or semi-conductive carrier removing roller 31 which is in contact with the image surface side of the print medium and to which an electric bias is applied.

Further, as shown in FIGS. 6 and 7, the carrier removing body is composed of a conductive or semi-conductive carrier removing belt 33 which is in contact with the image surface side of the print medium and to which an electric bias is applied. To do.

By adopting the above-described form, in the case of a non-oil-absorbing (non-penetrable) print medium such as a polyester sheet, the excess carrier solvent in the image does not penetrate into the print medium, and therefore, such as paper. Although a large amount of surplus oil remains as compared with the print medium, the carrier solvent on the print medium effectively removes the carrier solvent remaining on the image surface of the print medium.

Further, as shown in FIGS. 5 to 7, the carrier removing unit on the print medium applies an electric bias to the carrier removing body so that the toner does not move.

By adopting the above-mentioned form, particularly in a non-oil-absorbing (non-penetrative) print medium such as a polyester sheet, the toner image is attached to the carrier-removing body that comes into contact with the print medium. And do not transfer.

Further, as shown in FIG. 5, in the liquid developing electrophotographic apparatus, the rotation direction of the carrier removing member and the carrier removing backup member moves in the opposite direction at the contact portion with the surface of the print medium. (Hereinafter, also referred to as reverse rotation) so that the feed force of the discharge roller 35 for discharging the print medium installed downstream of the print medium on carrier removal unit is set to the feed on the print medium on carrier removal unit. It is configured to be larger than the force.

By adopting the above-mentioned configuration, by rotating the carrier removing member in the reverse direction, a high carrier recovery rate can be obtained especially in the case of a non-oil absorbing (non-penetrative) printing medium such as a polyester sheet. As a result, the carrier recovery efficiency is improved.

Further, as shown in FIG. 8, in the liquid developing electrophotographic apparatus, the rotation of the carrier removing member and the carrier removing backup member moves in the forward direction at the contact portion with the surface of the print medium. Printing which is installed downstream of the carrier removing unit on the print medium, while rotating in a direction (hereinafter also referred to as forward rotation), further rotating so as to move excessively at the contact portion with the surface of the print medium. The feed force of the discharge roller 35 for discharging the medium is set to be larger than the feed force of the above-mentioned print medium carrier removing unit.

By adopting the above-mentioned form, the carrier removing member and the carrier removing backup member are over-fed by forward rotation, and in particular, the printing medium is a non-oil absorbing (impermeable) printing such as a polyester sheet. Since the stress on the toner is low in the medium, the occurrence of image deterioration is prevented.

Further, as shown in FIG. 9, in the carrier-on-printing medium removing unit, the rotation direction of the carrier removing body is moved in the opposite direction at the contact portion with the image surface side of the printing medium. (Hereinafter, sometimes referred to as reverse rotation), and the rotation direction of the carrier removal backup body 32 is rotated so that the contact surface moves in the forward direction at the contact portion with the surface of the print medium (hereinafter, forward rotation). In some cases), carrier removal backup body 32
The feeding force is higher than the feeding force of the carrier removing body.

By adopting the above-mentioned form, the carrier removing body is rotated in the reverse direction and the carrier removing backup body is rotated in the forward direction, so that the carrier removing unit on the print medium can be contacted from the front end of the print medium. Accordingly, in particular, when the print medium is a non-oil-absorbing (non-permeable) print medium such as a polyester sheet, the print medium is stably conveyed by the feed force of the carrier-removing backup body that rotates forward.

[0051]

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.

FIG. 1 shows an embodiment of the present invention.

In the figure, a fixing unit included in a liquid developing electrophotographic apparatus using a non-volatile, high-viscosity and high-concentration liquid toner is composed of an image surface side heating body 11 and a print medium pressing body 12. The image side heating element 11 is
The toner image is heated and melted at the contact portion with the print medium 13 and fixed on the print medium 13. Print medium pressing body 12
Is installed so as to face the image-side heating body 11 with the print medium 13 interposed therebetween, and presses the print medium 13.

In the process of fixing the toner image on the print medium 13 in the fixing section by the fixing unit, a carrier removing member that comes into contact with the image surface side heating member 11 is provided, and an electric charge for moving the offset toner to the carrier removing member side. A carrier removing unit for applying a bias is provided.

The carrier removing body is the image surface side heating body 1.
1 is composed of a conductive or semi-conductive carrier removing roller 21 to which an electric bias is applied which is in contact with 1.
The rotation direction is reversely rotated so that the contact surface moves in the opposite direction at the contact portion with the image surface side heating body 11.

Further, the carrier removing roller 21 does not generate excessive rotation or stick-slip vibration due to the frictional resistance between the image-side heating body 11 and the carrier removing roller 21, so that the surface material has a friction coefficient. Composed of low material. The surface material is preferably, for example, a metal roller whose surface roughness is reduced to a mirror surface or a roller coated with a fluororesin.

The carrier removing unit is provided with, for example, a blade 22 for collecting the carrier solvent and a carrier collecting section 23 in order to collect the separated carrier solvent from the carrier removing roller 21.

Another embodiment of the carrier remover will be described below.

FIG. 2 shows an embodiment of the present invention.

In the figure, the carrier removing member is composed of a conductive or semi-conductive carrier removing belt 24 which is in contact with the image surface side heating member 11 and to which an electric bias is applied. The contact surface with the image-side heating body 11 is rotated so that the contact surface moves in the opposite direction. In addition, in the carrier removing unit, for example, a blade 22 for collecting the carrier solvent and a carrier collecting unit 23 are arranged in order to collect the carrier solvent separated and removed from the carrier removing belt.

1 and 2, the carrier removing member is rotated in the reverse direction to obtain a high carrier recovery rate, so that the carrier recovery efficiency is improved.

FIG. 3 shows an embodiment of the present invention.

In the same figure, the carrier removing body may be constituted by a blade 22 for recovering a conductive or semi-conductive carrier solvent which is in contact with the image surface side heating body 11 and to which an electric bias is applied.

In FIGS. 1 to 3, the electric bias applied to the carrier removing body composed of the carrier removing roller 21, the carrier removing belt 24 and the blade 22 is about 100V to 5KV.

In order to form an effective electric field between the carrier removing body and the image surface side heating body, the carrier removing body is made of a member whose resistance value is adjusted to a semiconductive range of about 1E4Ω to 1E9Ω. To do. Desirably, the resistance value of the carrier remover is set in the range of 1E4Ω to 1E7Ω.

With this configuration, in the process of fixing the toner image on the print medium, the high temperature offset toner and excess carrier solvent transferred from the toner image area and the print medium to the image side heating member are simply removed by the doctor blade. Instead, it is removed electrically.

In FIGS. 1 to 3, the surface of the image side heating element 11 is held in order to retain the carrier solvent which is separated from the molten toner at the fixing portion and adheres to the surface of the image side heating element 11. Coat with a material that does not swell in the carrier solvent. When the carrier solvent is silicone oil, for example, the material of the surface of the image-side heating body 11 is a material other than silicone rubber or silicone resin. As the material other than the silicone resin-based material, for example,
There are fluororesin coat and fluororubber.

FIG. 4 shows an embodiment of the present invention.

In the figure, the carrier removing member is composed of a conductive or semi-conductive carrier removing roller 21 which is in contact with the image surface side heating member 11 and which is applied with an electric bias. The contact surface is rotated so as to move in the forward direction at the contact portion with the side heating body 11, and the rotation speed of the carrier removing roller 21 is excessively fed at the contact portion with the image side heating body 11. Rotate to move.

With this structure, since the stress on the toner is low, the occurrence of image deterioration is prevented.

Next, an example of removing the carrier solvent remaining on the image surface of the print medium will be described.

FIG. 5 shows an embodiment of the present invention.

In the figure, in a liquid developing electrophotographic apparatus using a non-volatile, high-viscosity, high-concentration liquid toner, a non-oil absorbing (non-permeating) printing medium such as a polyester sheet (printing medium) 13a is used. After being transferred to
The fixing process is performed through the fixing unit. Further, for example, a polyester sheet (print medium) is provided downstream of the fixing unit.
A carrier removing unit on the print medium for removing the carrier solvent remaining on the image surface side of 13a is provided. The carrier removing unit on the print medium includes a carrier remover that contacts the image surface side of the polyester sheet (print medium) 13a,
And a carrier-removing backup body that is installed to face the carrier-removing body with the print medium interposed therebetween.

The carrier removing body is composed of a conductive or semi-conductive carrier removing roller 31 which is in contact with the image surface side of the polyester sheet (print medium) 13a and to which an electric bias is applied. The carrier removal backup body 32 is composed of a conductive or semiconductive roller. Further, the carrier removing roller 31 and the carrier removing backup body 32 are rotated so that the contact surface moves in the opposite direction at the contact portion with the surface of the polyester sheet (print medium) 13a.

Further, a discharge roller 35 for discharging the polyester sheet (print medium) 13a is installed downstream of the carrier-on-print medium removing unit composed of the carrier removing roller 31 and the carrier removing backup body 32. The feed force of the roller 35 is configured to be larger than the feed force of the carrier unit on the print medium, which includes the carrier removing roller 31 and the carrier removing backup body 32.

In the carrier removing unit on the print medium, in order to collect the separated and removed carrier solvent from the carrier removing roller 31, for example, a blade 22 for collecting the carrier solvent and a carrier collecting section 23 are arranged.

Another embodiment will be described below.

FIG. 6 shows an embodiment of the present invention.

In the figure, in the carrier removing unit on the print medium, the carrier remover is brought into contact with the image surface side of the polyester sheet (print medium) 13a. Consists of a belt. Further, the carrier removal backup body 34 is composed of a conductive or semi-conductive belt. The rotation direction of the carrier removal belt 33 and the carrier removal backup body 34 is rotated so that the contact surface moves in the opposite direction at the contact portion with the surface of the polyester sheet (print medium) 13a.

In the carrier removing unit on the print medium, the carrier solvent separated and removed is removed by the carrier removing belt 3
In order to collect the carrier solvent, the carrier solvent is collected, for example, the blade 22 and the carrier collecting unit 23 are arranged.

As shown in FIG. 7, the carrier removal backup body is a carrier removal backup composed of conductive or semi-conductive rollers that are installed to face the carrier removal belt 33 with the polyester sheet (print medium) 13a interposed therebetween. It may be the body 32.

With this structure, by rotating the carrier removing member in the reverse direction, a high carrier recovery rate can be obtained especially in the case of a non-oil absorbing (non-penetrative) printing medium such as a polyester sheet. Improves carrier recovery efficiency.

5 to 7, the carrier-removing-on-printing-medium unit has the carrier-removing roller so that the toner image does not adhere to or transfer to the carrier-removing member that contacts the printing medium. An electric bias of about 100 V to 5 KV that does not move the toner is applied to 31 or the carrier removing belt 33.

FIG. 8 shows an embodiment of the present invention.

In the figure, the carrier removing roller 31 and the carrier removing backup member 32 are rotated so that the contact surface moves in the forward direction at the contact portion with the surface of the polyester sheet (print medium) 13a, and further, The polyester sheet (print medium) 13a is rotated so as to move excessively at the contact portion with the surface thereof.

Further, a polyester sheet (print medium) 13 installed downstream of the carrier removing unit on the print medium
The feed force of the discharge roller 35 that discharges a is set to be larger than the feed force of the above-described print medium carrier removing unit.

Further, the carrier removing roller 31 is applied with an electric bias of about 100 V to 5 KV at which the toner does not move.

With this configuration, in a non-oil-absorbing (non-penetrative) printing medium such as a polyester sheet, the stress on the toner is low, and therefore the occurrence of image deterioration is prevented.

FIG. 9 shows an embodiment of the present invention.

In the figure, the carrier removing roller 31 is rotated so that the contact surface moves in the opposite direction at the contact portion with the image surface side of the polyester sheet (print medium) 13a, and the carrier removing backup member 32 is rotated. The rotation direction is rotated so that the contact surface moves in the forward direction at the contact portion with the surface of the polyester sheet (print medium) 13a.
Further, the feed force of the carrier removal backup body 32 is configured to be larger than the feed force of the carrier removal roller 31.

Further, the carrier removing roller 31 has
An electric bias of about 100 V to 5 KV is applied so that the toner does not move.

With this structure, the carrier removing unit on the print medium can be contacted from the front end of the print medium. The print medium is stably conveyed by the feed force of the carrier-removing backup member that rotates forward.

5 to 9, the toner image is heated and melted at the contact portion with the polyester sheet (print medium) 13a as shown in FIGS. ) In the process of fixing the toner image on the polyester sheet (print medium) 13a in the fixing portion including the image surface side heating body 11 fixed to 13a and the print medium pressing body 12 that presses the polyester sheet (print medium) 13a , The image side heating element 1
It is desirable to provide a carrier removing body such as a carrier removing roller 21 that comes into contact with 1 and to provide a carrier removing unit that applies an electric bias for moving the offset toner to the carrier removing body side.

[0094]

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

In a liquid-developing electrophotographic apparatus using a non-volatile, high-viscosity and high-concentration liquid toner, a toner image is heated and melted at a contact portion with a print medium, and is fixed on the print medium. In the process of fixing the toner image on the print medium in the fixing unit including the print medium pressing body that presses the print medium, a carrier removing body that contacts the image surface side heating body is provided, and the offset toner is applied to the carrier removing body side. By including a carrier removing unit that applies an electric bias for moving the toner, a high-temperature offset toner that is transferred from the toner image portion and the print medium to the image surface side heating body in the process of fixing the toner image on the print medium, Excess carrier solvent can be removed efficiently. That is, it can be removed by electrical action, rather than simply by a doctor blade.

Further, the carrier remover is composed of a member whose resistance value is adjusted to a semi-conductive range of about 1E4Ω to 1E9Ω, so that an effective electric field is provided between the carrier remover and the image side heater. Can be formed.

Furthermore, since the carrier removing unit obtains a high carrier recovery rate by rotating the carrier removing body in the reverse direction, the carrier recovery efficiency can be improved.

Further, the carrier removing member has a surface material made of a material having a low coefficient of friction, so that an excessive rotation load or stick slip is caused by frictional resistance between the image surface side heating member and the carrier removing member. Vibration can be prevented from occurring.

Further, the carrier removing unit can reduce excessive rotation load and vibration such as stick slip by over-feeding the carrier removing body in the forward rotation, and enhance the abrasion resistance of the contact member. .

Further, in the liquid developing electrophotographic apparatus, by covering the surface of the image-side heating element with a material that does not swell with the carrier solvent, the image-side heating element is separated from the molten toner in the fixing portion, and the image-side heating element is separated. The carrier solvent adhering to the surface can be retained, and the carrier can be efficiently recovered.

Further, in a liquid development electrophotographic apparatus which uses a non-volatile, high-viscosity, high-concentration liquid toner, carrier carrier on the print medium for removing the carrier solvent remaining on the image surface side of the print medium downstream of the fixing unit is removed. The carrier removing unit on the print medium is provided with a unit, and a carrier removing body that contacts the image surface side of the print medium, and a carrier removing backup body that is installed to face the carrier removing body with the print medium sandwiched therebetween. In the case of non-oil absorbing (non-penetrative) print media such as polyester sheet, the excess carrier solvent in the image does not penetrate into the print media, so more excess oil is generated than the print media such as paper. Although remaining, the carrier solvent on the print medium can effectively remove the carrier solvent remaining on the image surface of the print medium.

Furthermore, the carrier removing unit on the print medium applies a non-oil absorbing (non-penetrative) property to the carrier remover by applying an electric bias to the carrier remover so that the toner does not move. In the above print medium, it is possible to prevent the toner image from adhering to or transferring to the carrier-removed body that contacts the print medium.

Further, in the liquid developing electrophotographic apparatus, the carrier removing member and the carrier removing backup member are rotated in the reverse direction, and the feed force of the discharging roller is made larger than the feed force of the carrier removing unit on the print medium. With such a configuration, particularly in a non-oil absorbing (non-penetrable) printing medium such as a polyester sheet as the printing medium, a high carrier recovery rate can be obtained, so that the carrier recovery efficiency can be improved.

Further, in the liquid developing electrophotographic apparatus, the carrier removing member and the carrier removing backup member are over-fed by forward rotation, and the feed force of the discharge roller is against the feed force of the carrier removing unit on the print medium. By configuring the print medium to have a large size, it is possible to prevent the occurrence of image deterioration because the stress on the toner is low particularly in a non-oil absorbing (non-penetrative) print medium such as a polyester sheet. it can.

Further, since the carrier removing unit on the print medium rotates the carrier removing member in the reverse direction and the carrier removing backup member rotates in the forward direction, the carrier removing unit on the print medium can be contacted from the front end of the print medium. As a result, in particular, when the print medium is a non-oil-absorbing (non-permeable) print medium such as a polyester sheet, it is possible to stably convey the print medium by the feed force of the carrier-removing backup body that rotates forward. .

[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 diagram of an embodiment of the present invention.

FIG. 10 is a diagram of the prior art.

[Explanation of symbols]

11: Heating body on the image side 12: Printing medium presser 21: Carrier removing roller 22: Blade 23: Carrier Recovery Department 24: Carrier removal belt 31: Carrier removing roller 32: Carrier removal backup body 33: Carrier removal belt 34: Carrier removal backup body 35: discharge roller

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI theme code (reference) G03G 15/20 105 G03G 15/10 113 (72) Inventor Isao Nagata Unokenu, Unoku Town, Kawakita-gun, Ishikawa Prefecture No. 98, No. 2 Inventor Hironaga Honkawa, 72, PFU Co., Ltd. Unoki-nu, Unoki-cho, Hebei-gun, Ishikawa Prefecture No. 98 No. 2 Inventor, P-FU Co., Ltd. 72, Eri Yamanishi, Uno-cho, Hebei-gun, Ishikawa Prefecture No. 98, Ki-nu Co., Ltd. 2 PFU Co., Ltd. (72) Inventor Norihiro Yamasaku No. 2, Uno-ki, Hebei-gun, Kawasaki-gun, Ishikawa Prefecture No. 2 No. 2 F-P Co., Ltd. F-Term Co., Ltd. 2H033 AA08 AA45 AA49 BA10 BA12 BA13 BA49 BA50 BA51 BA54 BA55 BA57 BA58 BA59 BB02 BB05 BB17 BB37 CA36 CA40 2H069 BA00 DA06 2H072 CA01 JA02 2H074 AA03 BB42 BB43 BB50 BB56 BB58 BB60 BB72 EE07 3F049 DA12 LA01 LB03

Claims (16)

[Claims] 1. A liquid-developing electrophotographic apparatus using a non-volatile, high-viscosity, high-concentration liquid toner, in which a toner image is heated and melted at a contact portion with a print medium to be fixed on the print medium. In the process of fixing the toner image on the print medium in the fixing unit including the body and the print medium pressing body that presses the print medium, a carrier removing body that contacts the image side heating body is provided, and the carrier removing body side is provided. A liquid developing electrophotographic apparatus comprising a carrier removing unit for applying an electric bias for moving the offset toner. 2. The carrier removing body is composed of a conductive or semi-conductive carrier removing roller that is in contact with the image surface side heating body and is applied with an electric bias. Liquid developing electrophotographic device. 3. The carrier removing body is composed of a conductive or semi-conductive carrier removing belt to which an electric bias is applied, which is in contact with the image surface side heating body. Liquid developing electrophotographic device. 4. The carrier removing body is constituted by a blade for recovering a conductive or semi-conductive carrier solvent to which an electric bias is applied, which is in contact with the image surface side heating body. 1. The liquid developing electrophotographic apparatus according to 1. 5. The carrier removing body is composed of a member having a resistance value adjusted to a semi-conductive range of about 1E4Ω to 1E9Ω, and the carrier removing member according to any one of claims 1 to 4. Liquid developing electrophotographic device. 6. The carrier removing unit rotates the rotation direction of the carrier removing body so that the contact surface moves in the opposite direction at the contact portion with the image surface side heating body. 1 to claim 1
A liquid developing electrophotographic apparatus according to the item 1. 7. The liquid developing electrophotographic apparatus according to claim 6, wherein the carrier removing body has a surface material made of a material having a low friction coefficient. 8. The carrier removing unit rotates the rotation direction of the carrier removing body so that the contact surface moves in a forward direction at a contact portion with the image surface side heating body, and the carrier removing body rotates. 4. The liquid developing electrophotographic apparatus according to claim 1, wherein the speed is rotated so that the contact surface moves excessively at a contact portion with the image surface side heating body. . 9. The liquid developing electrophotographic apparatus according to claim 1, wherein the surface of the image-side heating body is coated with a material that does not swell in a carrier solvent.
A liquid developing electrophotographic apparatus according to the item 1. 10. A liquid-removing electrophotographic apparatus using a non-volatile, high-viscosity, high-concentration liquid toner, which removes carrier solvent remaining on the image side of the print medium downstream of the fixing unit to remove carrier from the print medium. A carrier removing unit on the print medium, the carrier removing unit being in contact with the image surface side of the print medium, and the carrier removing backup unit being installed to face the carrier removing unit with the print medium interposed therebetween. And a liquid developing electrophotographic apparatus. 11. The carrier removing body is composed of a conductive or semi-conductive carrier removing roller which is in contact with the image surface side of the print medium and to which an electric bias is applied. Liquid developing electrophotographic device. 12. The carrier removing body is composed of a conductive or semi-conductive carrier removing belt which is in contact with the image surface side of the print medium and to which an electric bias is applied. Liquid developing electrophotographic device. 13. The liquid developing electrophotographic apparatus according to claim 11, wherein the carrier removing unit on the print medium applies an electric bias to the carrier removing member so that toner does not move. 14. The liquid developing electrophotographic apparatus rotates the carrier removing member and the carrier removing backup member so that the contact surfaces move in opposite directions at the contact portion with the surface of the print medium. The feed force of a discharge roller that discharges a print medium installed downstream of the print medium carrier removal unit is configured to be larger than the feed force of the print medium carrier removal unit. The liquid developing electrophotographic apparatus according to claim 11 or 12. 15. The liquid development electrophotographic apparatus rotates the carrier removing member and the carrier removing backup member in a direction in which a contact surface moves in a forward direction at a contact portion with the surface of the print medium, and further, The carrier is rotated so as to be excessively moved at the contact portion with the surface of the print medium, and the feed force of a discharge roller for discharging the print medium installed downstream of the print medium carrier removing unit is applied to the print medium carrier removing unit. 13. The liquid developing electrophotographic apparatus according to claim 11 or 12, wherein the liquid developing electrophotographic apparatus is configured so as to be larger than the feeding force. 16. The carrier removing backup unit rotates the carrier removing member on the print medium so that the contact surface moves in the opposite direction at the contact portion with the image surface side of the print medium. Rotate the rotation direction of the body so that the contact surface moves in the forward direction at the contact portion with the surface of the print medium, and increase the feed force of the carrier removal backup body with respect to the feed force of the carrier removal body. The liquid developing electrophotographic apparatus according to any one of claims 10 to 12, wherein the liquid developing electrophotographic apparatus is configured.