JP2000305365A - Developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably hold a developing gap between a liquid coloring medium carrier and an electrostatic latent image carrier by arranging the liquid coloring medium carrier for developing an electrostatic latent image by sticking the liquid coloring medium to an electrostatic latent image carrier proximately to the electrostatic latent image carrier through a gap forming member. SOLUTION: The liquid coloring medium carrier 7 developing the electrostatic latent image formed on the electrostatic latent image carrier 2 as a toner image by supplying the liquid coloring medium to the outer peripheral surface of the carrier 2 is provided so that one part of the outer peripheral surface may project. Electrostatic latent image carrier rollers 27 rotating in contact with the carrier 7 and forming a specified uniform gap between the carriers 2 and 7 are respectively attached on a rotary shaft at both ends of the carrier 2. Thus, the developing gap between the carriers 2 and 7 is stably held and developing density is stabilized to eliminate irregular density.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device used for an image forming apparatus such as an electrophotographic apparatus, and more particularly, to a wet developing device for visualizing an electrostatic latent image with a liquid coloring medium.

[0002]

2. Description of the Related Art Developing devices employed in image forming apparatuses such as copying machines utilizing electrophotography are roughly classified into dry developing devices and wet developing devices. Among them, a liquid coloring medium used in a wet developing device is a dispersion of charged granular toner in a carrier liquid. For example, such a liquid coloring medium is formed on the surface of an electrostatic latent image carrier such as a photosensitive drum. When a liquid coloring medium is supplied, the toner is electrophoresed, adheres to the electrostatic latent image, and is visualized.

For example, a liquid coloring medium in which a toner composed of carbon black coated with a resin is dispersed in a carrier liquid composed of an aliphatic hydrocarbon such as “IsoparG” (trade name, manufactured by Exxon Corporation) is used as an electrostatic latent image. The liquid coloring medium is supplied between the surface of the electrostatic latent image carrier on which is formed and the counter electrode arranged at a uniform interval on the surface to bring the liquid coloring medium into contact with the surface of the electrostatic latent image carrier, and the carrier liquid The electrostatic latent image is developed by utilizing the electrophoresis phenomenon of charged toner in the inside.

In a wet developing apparatus using a liquid coloring medium,
There is an advantage that high resolution can be obtained due to the fineness of the toner particles and the like as compared with the dry developing device.

This liquid coloring medium is called a two-component liquid coloring medium because a carrier liquid is used for charging and moving the toner.

In a wet developing apparatus using such a two-component liquid coloring medium, the liquid coloring medium contacts not only the electrostatic latent image but also the non-latent image portion, and thus adheres to the electrostatic latent image carrier. The amount of the liquid coloring medium taken out is increased. For this reason, it is necessary to provide a means for removing excess liquid coloring medium on the surface of the electrostatic latent image carrier.

Further, since the liquid coloring medium comes into contact with the non-latent image portion, toner adheres to the non-latent image portion due to the action of residual charges in the non-latent image portion, and the image is soiled. is there.

Further, when the toner on the electrostatic latent image carrier is transferred to a transfer material to obtain a final image, the liquid adhering to the electrostatic latent image carrier regardless of the latent image portion and the non-latent image portion is obtained. Since the coloring medium is transferred to the transfer material, the transfer material immediately after the transfer of the toner image is in a wet state with the liquid coloring medium. Therefore, it is necessary to evaporate the solvent at the time of fixing, for example, before discharging the transfer material out of the apparatus. The amount of heat for evaporating the solvent not only occupies most of the amount of heat used in the image forming apparatus, but also around the image forming apparatus, the vapor concentration of the organic liquid evaporated by drying becomes high, which is inconvenient for the user. It can also give you pleasure.

As a wet developing apparatus for solving the above problems, there is one disclosed in Japanese Patent Application Laid-Open No. 55-143565. This uses a liquid coloring medium in which a coloring material is dispersed or dissolved in a liquid, and a non-contact protruding development at a gap between the liquid coloring medium on the liquid coloring medium carrier and the electrostatic latent image carrier, that is, a developing gap. Alternatively, jumping development is performed. Such a developing method is hereinafter referred to as a “non-contact wet developing method”.

The liquid coloring medium used in the non-contact wet developing system is such that the entire liquid behaves as a toner without the color material moving in the liquid, and corresponds to the carrier liquid in the two-component liquid coloring medium. For this reason, it is called a one-component liquid coloring medium.

Here, an image forming apparatus using a non-contact wet developing system will be described below.

In a non-contact wet development type image forming apparatus,
An electrostatic latent image carrier on which an electrostatic latent image is formed is rotatably supported by the apparatus main body. On the outer periphery of the electrostatic latent image carrier, a charger for uniformly charging the electrostatic latent image carrier, an exposure optical system for forming an electrostatic latent image on the electrostatic latent image carrier, and an electrostatic latent image are provided. A wet developing device for developing a visible image, a cleaning device for removing a coloring medium remaining on the outer surface of the electrostatic latent image carrier,
Static eliminators for removing the electrostatic latent image charge remaining on the electrostatic latent image carrier are sequentially arranged along the rotation direction of the electrostatic latent image carrier.

Inside the developing device, there is a liquid tank in which a liquid coloring medium is stored, and the liquid coloring medium carrying the liquid coloring medium is supplied to the outer surface of the electrostatic latent image carrier to visualize the electrostatic latent image. body,
A sponge-like foaming roller for supplying a liquid coloring medium, which absorbs the liquid coloring medium in the liquid tank and supplies it to the liquid coloring medium carrier, is provided. The liquid tank is connected with a carrier liquid cartridge for supplying a carrier liquid for dispersing the toner and a concentrated liquid coloring medium cartridge for supplying a concentrated liquid coloring medium.

The cleaning device includes a cleaning foam roller for pressing against the electrostatic latent image carrier, and a cleaning blade for the electrostatic latent image carrier having elasticity for pressing against the electrostatic latent image carrier. A cleaning liquid cartridge and a waste liquid treatment tank are connected to the cleaning device.

On the side of the image forming apparatus, a paper cassette containing paper is provided. A transfer roller for transferring the toner image on the electrostatic latent image carrier to a sheet is disposed at a position facing the developing surface of the electrostatic latent image carrier. A transfer material separating device that separates the paper from the electrostatic latent image carrier and a fixing device that fixes the toner image on the paper are sequentially arranged behind the transfer roller in the transport direction.

Next, the operation of the image forming apparatus thus configured will be described.

When image formation is started, the surface of the electrostatic latent image carrier is uniformly charged, and an electrostatic latent image is formed on such an electrostatic latent image carrier by an exposure optical system. And
The liquid coloring medium is supplied to the surface of the liquid coloring medium carrier by rotating the liquid coloring medium supply foam roller partially immersed in the liquid tank.

The liquid coloring medium supplied to the liquid coloring medium carrier is adjusted to a predetermined thickness by rotating the liquid coloring medium regulating member. Since a developing gap is formed between the liquid coloring medium film formed on the surface of the liquid coloring medium carrier and the surface of the electrostatic latent image carrier, the electric charge forming the electrostatic latent image is transferred to the developing unit. Upon arrival, the electric field of the electric charge causes the liquid coloring medium film to bulge or jump toward the electric charge and adhere to the electrostatic latent image carrier, whereby the electrostatic latent image is developed.

As a result, the electrostatic latent image formed on the electrostatic latent image carrier is visualized and transferred to a sheet by the transfer roller. Thereafter, the sheet is separated from the electrostatic latent image carrier by the transfer material separating device and transported to the fixing device, where the toner image is fixed.

The residual colored medium remaining on the electrostatic latent image carrier is removed by a cleaning device, and the residual electrostatic latent image on the electrostatic latent image carrier is removed by a static eliminator.

With respect to such an image forming apparatus using the non-contact wet developing method, as disclosed in Japanese Patent Application Laid-Open No. 7-20722, a piezoelectric element is provided in a developing gap, and an electric signal of the piezoelectric element is used to control the developing gap. Techniques for adjusting the interval have been proposed.

[0022]

However, even if the developing gap can be adjusted by the piezoelectric element, if the adjusted developing gap cannot be stably maintained, the developing density is unstable. This causes development density unevenness.

Accordingly, an object of the present invention is to provide a developing device capable of stably maintaining a developing gap between a liquid colored medium carrier and an electrostatic latent image carrier.

[0024]

To solve this problem, a developing device according to the present invention comprises an electrostatic latent image carrier on which an electrostatic latent image is formed, and a gap with respect to the electrostatic latent image carrier. A liquid coloring medium carrier that is disposed close to the forming member and adheres the liquid coloring medium onto the electrostatic latent image carrier to visualize the electrostatic latent image, and is rotated while being pressed against the liquid coloring medium carrier A liquid coloring medium supply foam roller for supplying the absorbed liquid coloring medium to the surface of the liquid coloring medium carrier, and a liquid coloring medium for regulating the thickness of the liquid coloring medium supplied to the surface of the liquid coloring medium carrier The configuration includes a regulating member and voltage applying means for applying a bias voltage between the liquid colored medium carrier and the electrostatic latent image carrier.

This makes it possible to stably maintain the development gap between the electrostatic latent image carrier and the liquid coloring medium carrier.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to an electrostatic latent image carrier on which an electrostatic latent image is formed, and a gap forming member with respect to the electrostatic latent image carrier. A liquid coloring medium carrier that is disposed in close proximity and adheres a liquid coloring medium on the electrostatic latent image carrier to visualize the electrostatic latent image, and a liquid that has been rotated while being pressed against the liquid coloring medium carrier and absorbed A liquid roller for supplying a color medium to the surface of the liquid medium carrier, a liquid medium control member for regulating the thickness of the liquid medium supplied to the surface of the medium, A developing device having voltage applying means for applying a bias voltage between the colored medium carrier and the electrostatic latent image carrier, wherein the developing gap between the electrostatic latent image carrier and the liquid colored medium carrier is stably maintained. Has the effect that it becomes possible to hold the

According to a second aspect of the present invention, in the first aspect of the invention, the gap forming members are respectively mounted on rotating shafts at both ends of the electrostatic latent image carrier, and the gap member is provided with a liquid coloring medium carrier. A developing device which is an electrostatic latent image carrier roller which rotates while being in contact with a body and forms a predetermined uniform gap between the electrostatic latent image carrier and the liquid coloring medium carrier; This has the effect that the developing gap between the carrier and the liquid coloring medium carrier can be stably maintained.

According to a third aspect of the present invention, in the first aspect of the present invention, the gap forming members are respectively mounted on rotating shafts at both ends of the liquid coloring medium carrier.
A developing device which is a liquid colored medium carrier roller that rotates in contact with the electrostatic latent image carrier and forms a predetermined uniform gap between the electrostatic latent image carrier and the liquid colored medium carrier, This has the effect that the developing gap between the electrostatic latent image carrier and the liquid colored medium carrier can be stably maintained.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the gap forming members are each provided with an electrostatic latent image carrier mounted on a rotating shaft at both ends of the electrostatic latent image carrier. The body roller and the liquid coloring medium carrier are respectively mounted on the rotating shafts at both ends, rotate while contacting the electrostatic latent image carrier roller, and between the electrostatic latent image carrier and the liquid coloring medium carrier. The developing device is a liquid coloring medium carrier roller that forms a predetermined uniform gap, and can stably maintain the development gap between the electrostatic latent image carrier and the liquid coloring medium carrier. Having.

According to a fifth aspect of the present invention, in the fourth aspect, a gap adjusting thin plate member is inserted between the electrostatic latent image carrier roller and the liquid coloring medium carrier roller. The developing device has a function that the gap can be finely adjusted and the film thickness of the liquid coloring medium can be more finely regulated.

According to a sixth aspect of the present invention, in the first aspect, the gap forming members are respectively attached to both ends of the electrostatic latent image carrier, and two gaps are provided with respect to the liquid coloring medium carrier. A developing device that is a pair of electrostatic latent image carrier rollers that rotate while contacting at a point and form a predetermined uniform gap between the electrostatic latent image carrier and the liquid coloring medium carrier; This has the effect that the development gap between the latent image carrier and the liquid colored medium carrier can be stably maintained.

According to a seventh aspect of the present invention, in the first aspect of the present invention, the gap forming members are attached to both ends of the liquid coloring medium carrier, respectively. A developing device that is a pair of liquid coloring medium carrier rollers that rotate while contacting at a point and form a predetermined uniform gap between the electrostatic latent image carrier and the liquid coloring medium carrier; This has the effect that the development gap between the image carrier and the liquid colored medium carrier can be stably maintained.

According to an eighth aspect of the present invention, in the second or fourth aspect of the present invention, the electrostatic latent image bearing roller is a developing device in which the roller is a bearing. Mutual friction between the body and the liquid coloring medium carrier is suppressed,
This has the effect that both rotations can be made smooth.

According to a ninth aspect of the present invention, in the third or fourth aspect of the present invention, there is provided a developing device in which the liquid-colored medium carrier roller is a bearing, and the electrostatic latent image carrier is provided. Friction between the liquid coloring medium carrier and the liquid coloring medium carrier is suppressed, and the rotation of both can be made smooth.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. In these drawings, the same members are denoted by the same reference numerals, and duplicate description is omitted.

FIG. 1 is a sectional view showing an image forming apparatus using a developing device according to one embodiment of the present invention, and FIG.
FIG. 3 is a cross-sectional view showing a developing device in the image forming apparatus of FIG. 2, FIG. 3 is an explanatory view showing an example of a holding structure of an electrostatic latent image carrier and a liquid colored medium carrier in the developing device of FIG. 2, and FIG. FIG. 5 is an explanatory view showing another example of the holding structure of the electrostatic latent image carrier and the liquid coloring medium carrier in the developing device. FIG. 5 is a diagram illustrating the electrostatic latent image carrier and the liquid coloring medium carrier in the developing device of FIG. FIG. 6 is an explanatory view showing still another example of the holding structure of FIG.
FIG. 7 is an explanatory view showing still another example of the holding structure of the electrostatic latent image carrier and the liquid coloring medium carrier in the developing device of FIG. It is explanatory drawing which shows another example of the holding structure with a body.

In FIG. 1, an electrostatic latent image carrier 2 on which an electrostatic latent image is formed is rotatably supported by an image forming apparatus 1. An organic photoconductor (OP) is provided on the surface of the electrostatic latent image carrier 2.
C), an amorphous silicon (a-Si) -based or selenium (Se) -based photosensitive receiving layer is applied. In the present embodiment, the electrostatic latent image carrier 2 has a drum shape, but may have a belt shape.

A charger 3 for uniformly charging the electrostatic latent image carrier 2 using corona discharge is provided on the outer periphery of the electrostatic latent image carrier 2, and a laser is turned on / off based on information from a host computer. Exposure optical system 4 for forming an electrostatic latent image on electrostatic latent image carrier 2, liquid colored medium L1 contributing to development (FIG. 2)
A wet developing device 5 for transferring the toner inside to the electrostatic latent image portion to develop the electrostatic latent image into a visible image, a light emitting diode, and the like are provided, and remain on the outer peripheral surface of the electrostatic latent image carrier 2. A cleaning device 13 for removing the remaining toner, and a static eliminator 11 for removing the electrostatic latent image charge remaining on the electrostatic latent image carrier 2 after removing the residual toner by light irradiation is provided in the rotation direction of the electrostatic latent image carrier 2 Are arranged in sequence.

As shown in FIG. 2, a liquid tank 12 is formed inside a housing 5a of the developing device 5, and a liquid coloring medium L1 is stored therein.

Further, the liquid coloring medium L1 is supplied to the outer peripheral surface of the electrostatic latent image carrier 2 to make the electrostatic latent image formed on the electrostatic latent image carrier 2 visible as a toner image. The body 7 is provided so as to protrude a part of the outer peripheral surface.

Further, the sponge-like foaming roller 6 for supplying the liquid coloring medium L1 in the liquid tank 12 and supplying it to the liquid coloring medium carrier 7 is pressed against the liquid coloring medium carrier 7 by pressing. Are located.

Then, a liquid coloring medium regulating member 21 for regulating the film thickness of the liquid coloring medium L1 supplied to the surface of the liquid coloring medium carrier 7 forms a uniform gap in the liquid coloring medium carrier 7 at the upper part of the housing 5a. It is placed close to holding.

A liquid coloring medium regulating member cleaning blade 22 is provided in pressure contact with the surface of the liquid coloring medium regulating member 21. Thereby, the liquid coloring medium regulating member 2
The liquid coloring medium L1 attached to the housing 1 is removed and dropped and collected into the liquid tank 12, and the housing 5 cooperates with the liquid coloring medium carrier 7 and the liquid coloring medium regulating member 21.
The liquid coloring medium L1 accommodated in a is shut off from the outside air. Therefore, the phenomenon that the carrier liquid in which the toner is dispersed evaporates and the concentration of the liquid coloring medium increases can be prevented.

The developing device 5 is provided with a voltage applying means 26 for applying a bias voltage between the liquid colored medium carrier 7 and the electrostatic latent image carrier 2.

Here, the holding structure of the electrostatic latent image carrier 2 and the liquid colored medium carrier 7 will be described with reference to FIGS.

In the case shown in FIG. 3, the electrostatic latent image carrier 2 rotates in contact with the liquid coloring medium carrier 7 on the rotating shafts at both ends, and the electrostatic latent image carrier 2 and the liquid An electrostatic latent image carrier roller (gap forming member) 27 that forms a predetermined uniform gap with the body 7 is attached.

In addition, in the case shown in FIG. 4, the liquid coloring medium carrier 7 rotates on the rotation shafts at both ends in contact with the electrostatic latent image carrier 2 and rotates with the electrostatic latent image carrier 2 in liquid coloring. Liquid colored medium carrier rollers (gap forming members) 28 that form a predetermined uniform gap with the medium carrier 7 are respectively attached.

Further, in the case shown in FIG. 5, the electrostatic latent image carrier rollers (gap forming members) 27 are respectively mounted on the rotating shafts at both ends of the electrostatic latent image carrier 2, and the liquid coloring medium carrier 7 is provided. On the rotation shafts at both ends, the electrostatic latent image carrier 2 rotates while contacting the electrostatic latent image carrier roller 27.
A liquid coloring medium carrier roller (gap forming member) 28 that forms a predetermined uniform gap between the liquid coloring medium carrier 7 and the liquid coloring medium carrier 7 is attached. In order to regulate the thickness of the liquid coloring medium L1 by adjusting the gap, a gap of a necessary amount is formed between the electrostatic latent image carrier roller 27 and the liquid coloring medium carrier roller 28. The adjustment thin plate member 29 is inserted.

In the case shown in FIG. 6, both ends of the electrostatic latent image carrier 2 are brought into contact with the liquid coloring medium carrier 7 at two points and rotated, and the electrostatic latent image carrier 2 is A pair of electrostatic latent image carrier rollers (gap forming members) 27 that form a predetermined uniform gap with the medium carrier 7 are respectively attached.

In the case shown in FIG. 7, the two ends of the liquid colored medium carrier 7 are brought into contact with the electrostatic latent image carrier 2 at two points and rotated. A pair of liquid coloring medium carrier rollers (gap forming members) 28 that form a predetermined uniform gap with the liquid coloring medium carrier 7 are respectively attached.

With the structure shown in FIGS. 3 to 7,
The developing gap between the electrostatic latent image carrier 2 and the liquid coloring medium carrier 7 can be stably maintained. This makes it possible to stabilize the development density and eliminate density unevenness.

Here, bearings can be used for the electrostatic latent image carrier roller 27 and the liquid colored medium carrier roller 28. By doing so, mutual friction between the electrostatic latent image carrier 2 and the liquid colored medium carrier 7 is suppressed, and both rotations can be made smooth.

In order to prevent the bias voltage applied between the liquid colored medium carrier 7 and the electrostatic latent image carrier 2 from leaking from the gap formed between them, the electrostatic latent image carrier is used. Body roller 27, liquid coloring medium supporting body roller 28,
The specific resistance of the gap adjusting thin plate member 29 is the liquid coloring medium L.
The specific resistance is preferably 1 or more, more preferably 1E + 06 Ω · cm or more.

Examples of such a high resistivity material include the following glass and polymer.

Glass materials include potassium lime glass, soda lime glass, borosilicate glass, crown glass, zinc crown glass, soda potassium glass, barium borosilicate glass, 96% silicate glass, 99.5% silicate glass, phosphate glass, Low melting glass, lithium silicate glass, zinc aluminum silicate glass, zirconium silicate glass, and the like can be used.

Examples of the polymer include acrylonitrile butadiene styrene, acetal, melamine, polyamide, polycarbonate, polyester, phenol, polyimide, oxidized polyphenol, polyphenol sulfide, ethylene propylene fluoride, acrylonitrile methyl methacrylate, polyamide, polyethylene, Polypropylene, polyvinyl chloride, polyvinylidene fluoride, butyl rubber, chlorosulfonated polyethylene, ethylene propylene rubber, furan / furfuryl alcohol resin, nitrile rubber, polychloroprene, polytetrafluoroethylene (trade name: "Teflon"), styrene, meta Acrylic, nylon, fluorine rubber, silicone rubber, polyurethane, EPDM, acrylic, polyethylene terephthalate Toshito or the like can be used.

The liquid coloring medium L1 is made of, for example, Iso.
For example, 1E + 12 composed of an aliphatic hydrocarbon such as parG
It is composed of a carrier liquid having a high specific resistance of Ω · cm or more and a toner composed of, for example, carbon black coated with a resin and positively charged and dispersed in the carrier liquid.

As shown in FIG. 1, the liquid tank 12 is connected to a carrier liquid cartridge 14 for supplying a carrier liquid for dispersing toner and a concentrated liquid coloring medium cartridge 15 for supplying a concentrated liquid coloring medium.

The cleaning device 13 includes a sponge-like cleaning foam roller 9 that is in pressure contact with the electrostatic latent image carrier 2 and an elastic body such as rubber. A latent image carrier cleaning blade 10 is provided. The cleaning device 13 is connected with a cleaning liquid cartridge 19 for replenishing a cleaning liquid using a carrier liquid for cleaning the electrostatic latent image carrier 2 and a waste liquid processing tank 20 for collecting waste liquid.

On the side of the image forming apparatus 1, a paper cassette 16 containing paper 16a as a transfer material is provided. A transfer roller 8 for transferring the toner image formed on the electrostatic latent image carrier 2 to the sheet 16a is provided at a position facing the developing surface of the electrostatic latent image carrier 2 with the sheet 16a interposed therebetween. Are located.

Further, behind the transfer roller 8 in the transport direction, a transfer material separating device 17 for removing electricity from the paper 16a by corona discharge and separating it from the electrostatic latent image carrier 2, and a transfer material separating device 17 A fixing device 18 for fixing the toner image transferred to the paper 16a separated from the electrostatic latent image carrier 2 by the above-mentioned is sequentially arranged. And paper 1
The toner image is fixed to 6 a by the pressure and heat when passing through the inside of the fixing device 18.

The operation of the image forming apparatus thus configured will be described below.

When image formation is started, first, as a charging step, a corona discharge is performed by a charger 3 connected to a high-voltage power supply to uniformly charge the surface of the electrostatic latent image carrier 2. Next, in the exposure step, the laser of the exposure optical system 4 is turned on / off by information sent from the host computer, and the charge on the surface of the electrostatic latent image carrier 2 rotated in the circumferential direction is partially eliminated. As a result, an electrostatic latent image is formed.

In the subsequent developing step, the liquid tank 12
The liquid coloring medium L1 is supplied to the surface of the liquid coloring medium carrier 7 by rotating the liquid coloring medium supplying foam roller 6 partially immersed in the liquid coloring medium L1. The liquid coloring medium L1 supplied to the liquid coloring medium carrier 7 is adjusted to a predetermined thickness by rotating the liquid coloring medium regulating member 21.

The paper 16 a is transported from the paper cassette 16 to the transfer roller 8. Then, the development of the toner image on the electrostatic latent image carrier 2 is completed, and the paper 16 a is transferred to the transfer roller 8.
The transfer roller 8 comes into contact with the electrostatic latent image carrier 2 at substantially the same time when the transfer roller 8 is conveyed. Then, by applying a predetermined level of transfer bias, the toner image on the electrostatic latent image carrier is transferred to the sheet 16a.

Here, since the paper 16 a is a dielectric material, it is charged when a high voltage is applied and is electrostatically attracted to the electrostatic latent image carrier 2. Therefore, almost at the same time as the paper 16a is conveyed to the transfer roller 8, corona discharge is performed by the transfer material separation device 17 by an AC bias, and the paper 16a is discharged. When the sheet 16a is completely discharged, the electrostatic attraction force between the sheet 16a and the electrostatic latent image carrier 2 decreases, and the sheet 16a is separated from the electrostatic latent image carrier 2 by stiffness and its own weight. .

The separated paper 16a is conveyed to the fixing device 18 where the toner image is fixed, and the image formation is completed.

On the other hand, the toner remaining on the electrostatic latent image carrier 2 without being transferred to the paper 16 a is
Removed by That is, the cleaning liquid supplied from the cleaning liquid cartridge 19 is diffused to the cleaning foam roller 9, and the cleaning foam roller 9 and the cleaning blade 1 for the electrostatic latent image carrier are dispersed.
0 cleaning. Further, the electrostatic latent image carrier 2
Is removed by the charge remover 11. As a result, the electrostatic latent image carrier 2 enters a standby state for forming a new image.

[0069]

As described above, according to the present invention, there is obtained an effective effect that the development gap between the electrostatic latent image carrier and the liquid coloring medium carrier can be stably maintained. .

As a result, an effective effect of stabilizing the development density and eliminating the density unevenness can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an image forming apparatus using a developing device according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a developing device in the image forming apparatus of FIG. 1;

FIG. 3 is an explanatory diagram showing an example of a holding structure of an electrostatic latent image carrier and a liquid colored medium carrier in the developing device of FIG. 2;

FIG. 4 is an explanatory view showing another example of a holding structure of the electrostatic latent image carrier and the liquid colored medium carrier in the developing device of FIG. 2;

FIG. 5 is an explanatory view showing still another example of a structure for holding the electrostatic latent image carrier and the liquid colored medium carrier in the developing device of FIG. 2;

FIG. 6 is an explanatory view showing still another example of a structure for holding the electrostatic latent image carrier and the liquid colored medium carrier in the developing device of FIG. 2;

FIG. 7 is an explanatory diagram showing still another example of a holding structure of the electrostatic latent image carrier and the liquid colored medium carrier in the developing device of FIG. 2;

[Explanation of symbols]

 2 Electrostatic Latent Image Carrier 5 Developing Device 6 Liquid Colored Medium Supply Foam Roller 7 Liquid Colored Media Carrier 21 Liquid Colored Medium Regulator 26 Voltage Applying Unit 27 Electrostatic Latent Image Carrier Roller (Gap Forming Member) 28 Liquid Coloring Medium carrier roller (gap forming member) 29 Thin plate member for gap adjustment L1 Liquid coloring medium

Claims (9)

[Claims] An electrostatic latent image carrier on which an electrostatic latent image is formed; and an electrostatic latent image carrier, wherein the electrostatic latent image carrier is disposed close to the electrostatic latent image carrier via a gap forming member, and is disposed on the electrostatic latent image carrier. A liquid-colored-medium carrier for adhering a liquid-colored medium to visualize the electrostatic latent image; and a liquid-colored-medium carrier that rotates while being pressed against the liquid-colored-medium carrier and absorbs the absorbed liquid-colored medium. A liquid roller for supplying a liquid coloring medium to be supplied to the surface of the liquid coloring medium, a liquid coloring medium regulating member that regulates the thickness of the liquid coloring medium supplied to the surface of the liquid coloring medium carrier, and the liquid coloring medium carrier. And a voltage applying means for applying a bias voltage to the electrostatic latent image carrier. 2. The image forming apparatus according to claim 1, wherein the gap forming members are respectively mounted on rotating shafts at both ends of the electrostatic latent image carrier, rotate while contacting the liquid coloring medium carrier, and rotate with the electrostatic latent image carrier. 2. The developing device according to claim 1, wherein the roller is an electrostatic latent image carrier that forms a predetermined uniform gap with the liquid coloring medium carrier. 3. The gap forming member is mounted on a rotating shaft at both ends of the liquid coloring medium carrier, and rotates while contacting with the electrostatic latent image carrier. 2. The developing device according to claim 1, wherein the roller is a liquid coloring medium carrier that forms a predetermined uniform gap with the liquid coloring medium carrier. 4. The image forming apparatus according to claim 1, wherein the gap forming member includes an electrostatic latent image carrier roller attached to a rotating shaft at both ends of the electrostatic latent image carrier, and a rotating shaft at both ends of the liquid coloring medium carrier. A liquid coloring medium carrier that rotates in contact with the electrostatic latent image carrier roller and forms a predetermined uniform gap between the electrostatic latent image carrier and the liquid coloring medium carrier. The developing device according to claim 1, wherein the developing device is a body roller. 5. A developing device according to claim 4, wherein a gap adjusting thin plate member is inserted between said electrostatic latent image carrier roller and said liquid coloring medium carrier roller. 6. The electrostatic latent image carrier is attached to both ends of the electrostatic latent image carrier, contacts the liquid colored medium carrier at two points, and rotates. 2. The developing device according to claim 1, wherein a pair of electrostatic latent image bearing rollers form a predetermined uniform gap between the electrostatic latent image bearing member and the liquid coloring medium carrier. 7. The gap-forming member is attached to each end of the liquid-colored-medium carrier, contacts the electrostatic-latent-image carrier at two points, rotates, and rotates the electrostatic-latent-image carrier. 2. The developing device according to claim 1, wherein the developing device comprises a pair of rollers for forming a predetermined uniform gap between the roller and the liquid-colored medium carrier. 8. The developing device according to claim 2, wherein said electrostatic latent image bearing roller is a bearing. 9. The developing apparatus according to claim 3, wherein said liquid-colored medium carrier roller is a bearing.