JP2007193158A - Wet type fixing device and image forming apparatus having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wet type fixing device for preventing distortion of a toner image, and to provide an image forming apparatus having the wet type fixing device. <P>SOLUTION: The printer 1 as the electrophotographic image forming apparatus includes an intermediate transfer belt 8 to which a toner image T is transferred; and the wet type fixing device 11 that applies a fixing liquid to the toner image T. The wet type fixing device 11 has: an application roller 19 that applies the fixing liquid to the toner image T; and an opposite roller 20 disposed opposite to the application roller 19 via the intermediate transfer belt 8. The fixing liquid is applied from the circumference 19a of the application roller 19 to the toner image T transferred to the external circumferential face 8a of the intermediate transfer belt 8. In addition, the opposite roller 20 has been charged to the polarity opposite to that of the toner T. The toner image T has been electrically attracted to the external circumferential face 8a of the intermediate transfer belt 8. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wet fixing apparatus that applies a fixing liquid to a toner image, thereby causing the toner to have an adhesive force, and uses the adhesive force to fix the toner image on a recording material, and an image forming apparatus including the wet fixing device. .

An image forming apparatus such as a printer is provided with a wet fixing device that applies a fixing solution to a toner image to cause the toner to have an adhesive force, and uses the adhesive force to fix the toner image on a recording material such as paper. There is something to prepare.
As such a wet fixing apparatus, for example, there is an apparatus including an intermediate transfer belt, a fixing liquid application roller, and a fixing liquid tank. The intermediate transfer belt is endless, and a toner image is transferred to the outer peripheral surface thereof. The peripheral surface of the fixing liquid application roller is in contact with the outer peripheral surface of the intermediate transfer belt, and the fixing liquid pumped from the fixing liquid tank is transferred from the peripheral surface of the fixing liquid application roller to the outer peripheral surface of the intermediate transfer belt. The toner image is applied to the toner image (see, for example, Patent Document 1).
JP 2004-109747 A

However, in the wet fixing device described in Patent Document 1, when the fixing liquid application roller applies the fixing liquid to the toner image on the intermediate transfer belt, the toner is dragged by the peripheral surface of the fixing liquid application roller, and the toner image is disturbed. May occur.
The present invention has been made under such a background, and an object thereof is to provide a wet fixing apparatus capable of preventing a toner image from being disturbed and an image forming apparatus having the wet fixing apparatus.

  In order to achieve the above object, the invention according to claim 1 is a wet type in which a fixing liquid is applied to a toner image to cause the toner to have an adhesive force, and the toner image is fixed on the recording material using the adhesive force. In the fixing device, a transfer material (2, 19) having a transfer surface (19a, 23) onto which a toner image (T) is transferred, a fixer tank (18) for storing a fixer, and a peripheral surface (19a). ) And the fixing liquid application roller (19) for drawing the fixing liquid from the fixing liquid tank and applying the fixing liquid to the toner image transferred from the peripheral surface to the transfer surface, and the back surface of the transfer surface of the transfer material. And an electrode member (20, 22) facing the fixing liquid application roller via a transfer material, and the electrode member is given a charge having a polarity opposite to that of the toner. Device (11).

In addition, the alphanumeric characters in parentheses represent corresponding components in the embodiments described later. The same applies hereinafter.
According to this configuration, the fixing liquid application roller draws the fixing liquid from the fixing liquid tank by its peripheral surface, and applies the fixing liquid to the toner image transferred from the peripheral surface to the transfer surface. Further, the electrode member disposed on the back surface of the transfer material of the transfer material is given a charge having a polarity opposite to that of the toner, and the positively or negatively charged toner is electrically transferred to the transfer material. Be attracted. Accordingly, when the fixing liquid application roller applies the fixing liquid to the toner image on the transfer surface, it is possible to prevent the toner image from being dragged by the fixing liquid application roller and causing the toner image to be disturbed.

According to a second aspect of the present invention, the electrode member is a counter roller (20) facing the fixing liquid application roller via a transfer material, and the peripheral surface of the fixing liquid application roller and the peripheral surface (20a) of the counter roller. The wet fixing apparatus according to claim 1, wherein the two are arranged so as to face each other.
According to this configuration, the peripheral surface of the opposing roller is disposed so as to face the peripheral surface of the fixing liquid application roller via the transfer material, and the transfer material is predetermined by the fixing liquid application roller and the opposing roller. Led in the direction of. Further, since the opposing roller functions as an electrode member, it is possible to prevent the toner image from being disturbed.

According to a third aspect of the present invention, the electrode member is a plate-like member (22) that faces the fixing liquid application roller via the transfer material, and the plate-like member moves the transfer material in a predetermined direction (X1). 2. The wet fixing device according to claim 1, wherein the wet fixing device is held by a guide member (21) for guiding to the outside.
According to this configuration, the transfer material can be guided in a predetermined direction by the fixing liquid application roller and the guide member. Further, since the plate member as the electrode member is held by the guide member, it is possible to prevent the toner image from being disturbed.

The invention described in claim 4 is characterized in that the material to be transferred includes a recording material (2) or a transfer belt (8) for transferring a toner image to the recording material. The wet fixing apparatus according to Item 1.
According to this configuration, even when the fixing liquid is applied to the toner image transferred to the recording material such as paper or the toner image transferred to the transfer belt, the toner image can be prevented from being disturbed.

According to a fifth aspect of the present invention, there is provided an image forming unit (30 to 34) for forming a toner image based on image data, and a toner image formed by the image forming unit according to any one of the first to fourth aspects. An image forming apparatus (1,200) comprising the wet fixing device according to Item 1.
According to this configuration, it is possible to prevent the toner image from being disturbed and obtain a good image quality.

Embodiments of the present invention will be specifically described below with reference to the drawings.
FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a printer 1 as an image forming apparatus including a wet fixing device 11 according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view schematically showing the wet fixing device 11 in FIG.
Referring to FIG. 1, a printer 1 is provided along a cassette 3 in which a sheet 2 as a recording material is accommodated, a sheet conveyance path 4 through which a sheet 2 in the cassette 3 is conveyed, and a sheet conveyance path 4. A transfer device 5 for transferring the toner image T onto the paper 2 and a discharge roller provided along the paper transport path 4 for discharging the paper 2 on which the toner image T has been transferred by the transfer device 5 to the outside of the apparatus. Pair 6 is provided.

The transfer device 5 includes a pair of transfer rollers 7 a and 7 b provided with the sheet conveyance path 4 interposed therebetween, and an endless intermediate transfer belt 8. The intermediate transfer belt 8 is stretched around one transfer roller 7a and a plurality of support rollers 9, and is rotationally driven in the circumferential direction of the intermediate transfer belt 8 by a drive source (not shown).
Around the intermediate transfer belt 8, a plurality (four in the present embodiment) of image forming units 30 to 33 for forming toner images T based on image data sent to the printer 1, and image forming units A wet fixing device 11 for applying a fixing solution to the toner image T transferred from 30 to 33 to the intermediate transfer belt 8 is provided.

  The image forming units 30 to 33 are for forming toner images T of different colors. Specifically, the image forming units 30 to 33 form toner images T corresponding to the respective colors of yellow, magenta, cyan, and black. Can do. Each of the image forming units 30 to 33 includes a photosensitive drum 12 and a charging device 13, an exposure device 14, a developing device 15, a static elimination device 16, and a cleaning device 17 provided around the photosensitive drum 12. Yes. A predetermined electrostatic latent image is formed on the peripheral surface 12 a of the photosensitive drum 12 by an electrophotographic method, and the electrostatic latent image is developed by the developing device 15 to form a toner image T.

  The photosensitive drums 12 provided in the image forming units 30 to 33 are arranged so that the peripheral surface 12 a thereof is in contact with the outer peripheral surface 8 a of the intermediate transfer belt 8. Each photosensitive drum 12 is rotationally driven by a driving source (not shown). Thereby, the toner image T formed on the peripheral surface 12 a of the photosensitive drum 12 can be transferred to the outer peripheral surface 8 a of the intermediate transfer belt 8. That is, in the present embodiment, the intermediate transfer belt 8 serves as a transfer material, and the outer peripheral surface 8a of the intermediate transfer belt 8 corresponds to the transfer surface.

The toner images T formed on the peripheral surface 12a of each photoconductor drum 12 are transferred to the outer peripheral surface 8a of the intermediate transfer belt 8 so as to overlap each other. As a result, a full-color toner image T is formed on the outer peripheral surface 8 a of the intermediate transfer belt 8.
Referring to FIGS. 1 and 2, wet fixing device 11 includes a fixing liquid tank 18 that stores fixing liquid, and an application roller that applies fixing liquid to toner image T transferred to outer peripheral surface 8 a of intermediate transfer belt 8. 19 and an opposing roller 20 as an electrode member facing the applying roller 19 with the intermediate transfer belt 8 interposed therebetween.

  Although not shown, the application roller 19 and the counter roller 20 extend in the width direction of the intermediate transfer belt 8 (in FIG. 1 and FIG. 2, the direction perpendicular to the paper surface), and are equal to or greater than the width of the intermediate transfer belt 8. Each has an axial length. Further, the applying roller 19 is disposed on the outer peripheral side of the intermediate transfer belt 8, and the opposing roller 20 is disposed on the inner peripheral side of the intermediate transfer belt 8. That is, the applying roller 19 and the opposing roller 20 are arranged so as to sandwich the intermediate transfer belt 8 in the thickness direction. Thus, the intermediate transfer belt 8 is guided in the rotation direction X1 of the intermediate transfer belt 8 by the applying roller 19 and the opposing roller 20.

The applying roller 19 is disposed such that the peripheral surface 19a thereof is in contact with the outer peripheral surface 8a of the intermediate transfer belt 8, and is rotationally driven by a driving source (not shown).
The fixing liquid tank 18 is for storing the fixing liquid applied to the toner image T transferred to the outer peripheral surface 8 a of the intermediate transfer belt 8, and the applying roller 19 can enter the fixing liquid tank 18. Yes. The applying roller 19 is immersed in the fixing liquid over a part of the circumferential direction in the fixing liquid tank 18 in the axial direction. The fixing liquid in the fixing liquid tank 18 adheres to the peripheral surface 19a of the applying roller 19 due to the surface tension, and is pumped from the fixing liquid tank 18 as the applying roller 19 rotates.

  The fixer pumped from the fixer tank 18 is applied to the outer peripheral surface 8a of the intermediate transfer belt 8 from the peripheral surface 19a of the applying roller 19, and is transferred to the toner image T transferred to the outer peripheral surface 8a of the intermediate transfer belt 8. Fixer is applied. As a result, the toner T is dissolved or swollen by the fixing solution to form an elastic gum and generate an adhesive force. The toner T moves to a predetermined transfer position by the rotation of the intermediate transfer belt 8 while the adhesiveness is generated, and the outer peripheral surface 8a of the intermediate transfer belt 8 and the surface of the sheet 2 between the pair of transfer rollers 7a and 7b. Is transferred to the paper 2 due to the difference in frictional force. Then, the toner T transferred to the surface of the paper 2 is hardened by the evaporation (vaporization) of the fixing liquid, and is fixed and fixed to the paper 2.

  On the other hand, a predetermined charge is applied to the opposing roller 20 facing the applying roller 19 via the intermediate transfer belt 8, and the opposing roller 20 is charged positively or negatively (in this embodiment, negatively). That is, electric charge remains in the toner particles in the toner image T formed through the electrophotographic method, and the toner T is charged positively or negatively (positively in this embodiment). A charge having a polarity opposite to that of the toner T is applied to the peripheral surface 20 a of the facing roller 20, and the facing roller 20 is charged to have a polarity opposite to that of the toner T.

  As a result, the toner T is electrically attracted toward the counter roller 20. Further, since the opposing roller 20 is disposed on the inner peripheral surface 8b side that is the back surface of the outer peripheral surface 8a of the intermediate transfer belt 8, the toner image T on the outer peripheral surface 8a is attracted toward the outer peripheral surface 8a. Therefore, when the fixing liquid is applied from the application roller 19 to the toner image T on the outer peripheral surface 8 a of the intermediate transfer belt 8, the fixing liquid is applied to the peripheral surface 19 a of the application roller 19 due to the surface tension and adhesiveness of the fixing liquid. It is possible to prevent the toner image T from adhering and being dragged to the peripheral surface 19a of the applying roller 19 to cause the toner image T to be disturbed. As a result, an undistorted toner image T can be transferred to the paper 2 to achieve good image quality.

FIG. 3 is an enlarged cross-sectional view schematically showing a wet fixing apparatus 11 according to another embodiment of the present invention. In FIG. 3, the same components as those shown in FIGS. 1 and 2 described above are denoted by the same reference numerals as those in FIGS. 1 and 2, and the description thereof is omitted.
Referring to FIG. 3, the present embodiment is mainly different from the above-described embodiment in that a guide member 21 facing the applying roller 19 is provided via the intermediate transfer belt 8, and the electrode member serves as an electrode member. The plate member 22 is held by the guide member 21.

Although not shown, the plate-like member 22 extends in the width direction of the intermediate transfer belt 8 and has a length equal to or greater than the width of the intermediate transfer belt 8. Further, the plate-like member 22 is charged with a polarity opposite to that of the toner T. The guide member 21 can guide the intermediate transfer belt 8 together with the applying roller 19 in the rotation direction X1.
According to this embodiment, the plate-like member 22 is arranged on the inner peripheral surface 8b side, which is the back surface of the outer peripheral surface 8a of the intermediate transfer belt 8 to which the toner image T is transferred, as in the above-described embodiment. By charging the member 22 with a polarity opposite to that of the toner T, it is possible to prevent the toner image T from being disturbed and to achieve good image quality.

FIG. 4 is a schematic cross-sectional view showing a schematic configuration of a main part of a printer 200 as an image forming apparatus including the wet fixing device 11 according to still another embodiment of the present invention.
4, the same components as those shown in FIGS. 1 to 3 described above are denoted by the same reference numerals as those in FIGS.
Referring to FIG. 4, the present embodiment is mainly different from the above-described embodiment in that the toner image T formed by the image forming unit 34 is directly transferred to the sheet 2, and the wet fixing device 11 performs the sheet transfer. 2 is to apply the fixing solution directly.

The image forming unit 34 includes the photosensitive drum 12 and a charging device 13, an exposure device 14, a developing device 15, a transfer roller 25, a static elimination device 16, and a cleaning device 17 provided around the photosensitive drum 12.
The toner image T formed on the peripheral surface 12 a of the photosensitive drum 12 is transferred to one surface 23 of the sheet 2 conveyed through the sheet conveying path 4 between the photosensitive drum 12 and the transfer roller 25. That is, in the present embodiment, the sheet 2 serves as a transfer material, and one surface 23 of the sheet 2 corresponds to the transfer surface.

  Then, a fixing liquid is applied to the toner image T transferred to one surface 23 of the sheet 2 by the applying roller 19, and the toner image T is fixed to the sheet 2. At this time, the toner image T transferred to one surface 23 of the paper 2 is electrically attracted by the opposing roller 20 disposed on the other surface 24 side of the paper 2, and the toner image T is disturbed. Is prevented. Thereby, good image quality can be achieved. Also, the configuration of the printer 200 can be simplified as compared with the embodiment of FIGS.

In this embodiment, the wet fixing apparatus 11 includes the fixing liquid tank 18, the applying roller 19, and the counter roller 20. However, the wet fixing apparatus 11 includes the fixing liquid tank 18 shown in FIG. The roller 19, the guide member 21, and the plate-like member 22 may be provided.
The present invention is not limited to the contents of the above embodiments, and various modifications can be made within the scope of the claims. For example, in the above embodiment, an example in which the image forming apparatus is a printer has been described. However, the image forming apparatus may be a copying machine or a facsimile. Further, the image forming apparatus may be a multifunction peripheral having two or more functions of a printer, a copier, or a facsimile.

  In the above embodiment, the example in which the peripheral surface 19 a of the applying roller 19 is in contact with the outer peripheral surface 8 a of the intermediate transfer belt 8 has been described. However, the peripheral surface 19 a of the applying roller 19 is the outer peripheral surface of the intermediate transfer belt 8. For example, the applying roller 19 may be disposed so that the peripheral surface 19 a of the applying roller 19 is close to the outer peripheral surface 8 a of the intermediate transfer belt 8.

1 is a schematic cross-sectional view showing a schematic configuration of a printer as an image forming apparatus including a wet fixing device according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view schematically showing the wet fixing device in FIG. 1. It is an expanded sectional view showing roughly a wet fixing device in another embodiment of the present invention. FIG. 10 is a schematic cross-sectional view illustrating a schematic configuration of a main part of a printer as an image forming apparatus including a wet fixing device according to still another embodiment of the present invention.

Explanation of symbols

1,200 printer (image forming device)
2 Paper (recording material, transferred material)
8 Intermediate transfer belt (transfer material, transfer belt)
8a Outer peripheral surface (transferred surface)
11 Wet Fixing Device 18 Fixing Liquid Tank 19 Application Roller (Fixing Liquid Application Roller)
19a Peripheral surface (peripheral surface of fixing liquid application roller)
20 Opposite roller (electrode member)
20a Peripheral surface (peripheral surface of opposed roller)
21 Guide member 22 Plate member (electrode member)
30 to 34 Image forming unit 23 One surface (transfer target surface)
T toner, toner image X1 rotation direction (predetermined direction)

Claims (5)

In a wet fixing apparatus in which a fixing liquid is applied to a toner image to generate an adhesive force on the toner, and the toner image is fixed on a recording material using the adhesive force.
A transfer material having a transfer surface onto which a toner image is transferred;
A fixer tank for storing fixer;
A fixing liquid application roller that draws the fixing liquid from the fixing liquid tank by the peripheral surface and applies the fixing liquid to the toner image transferred from the peripheral surface to the transfer surface;
An electrode member disposed on the back side of the transfer surface of the transfer material, and facing the fixing liquid application roller via the transfer material;
The wet fixing apparatus, wherein the electrode member is given a charge having a polarity opposite to that of the toner.   The electrode member is a facing roller that faces the fixing liquid application roller via a transfer material, and is arranged such that the peripheral surface of the fixing liquid application roller and the peripheral surface of the counter roller face each other. The wet fixing apparatus according to claim 1.   The electrode member is a plate-like member facing the fixing liquid application roller via a transfer material, and the plate-like member is held by a guide member that guides the transfer material in a predetermined direction. The wet fixing apparatus according to claim 1.   The wet fixing apparatus according to claim 1, wherein the transfer material includes a recording material or a transfer belt for transferring a toner image onto the recording material. An image forming unit for forming a toner image based on the image data;
An image forming apparatus comprising: the wet fixing device according to claim 1 for fixing a toner image formed by the image forming unit.

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