WO1995015516A1

WO1995015516A1 - Liquid developing apparatus for electrostatic latent image

Info

Publication number: WO1995015516A1
Application number: PCT/JP1994/002034
Authority: WO
Inventors: Masahiko Itaya; Tsutomu Sasaki; Toshihiro Saito; Hiroyuki Nakakoshi
Original assignee: Nippon Steel Corporation
Priority date: 1993-12-02
Filing date: 1994-12-02
Publication date: 1995-06-08

Abstract

An apparatus for developing an electrostatic latent image formed on a photosensitive member (10) by a toner. The developing apparatus includes a pre-wet device (20) for applying a pre-wet solution to the photosensitive member (10), and a developing device (20) for uniformly coating the latent image surface of the photosensitive member (10) with a high-viscosity liquid developer (508), which is a high-density suspension of toner in an insulating liquid and is carried onto the latent image in the form of film that is spread to a regulated thickness of 5-40 νm on a belt (510) by a feeder (504). According to the apparatus, a small amount of the liquid developer can be supplied uniformly to the latent image surface of an image support. The developer feeder (504) may be a layer formation blade so disposed as to come into contact with the developing belt or at least two rollers or a circular cylinder coated with a thin sponge layer.

Description

Description Liquid developing device for electrostatic latent images This application is assigned to the assignee of the present application and the Japan Patent Office is the receiving office under the name of `` Liquid developing method and liquid developing device ''. PCT application filed on January 0 PCTZJP 94/011541, and similarly PCT application filed on January 30, 1994 under the name `` Image forming apparatus and method '' PCTZJP 9 4 // and the contents of these application specifications are incorporated by reference as part of the present application.

Technical field

The present invention relates to an electrostatic latent image liquid developing apparatus that visualizes an electrostatic latent image formed by a method such as electrophotography, electrostatic recording, or ionography using a liquid developer. is there. Background art

Conventionally, in an electrostatic latent image liquid developing apparatus for developing an electrostatic latent image formed on an image support with toner, which is a charged visualized particle, a latent image on the image support is used. When supplying the liquid developer to the surface, a method is used in which irregularities are provided on the surface of the developing roller, which is a developer support, and the liquid developer is held in the recess and supplied to the image support. The sponge roller is pressed against the image support using an imager, and the liquid developer absorbed by the sponge roller is imaged. The liquid developer is directly supplied to the image support without using the developer support by supplying the image support to the support or by immersing the image support in a developer tank in which the liquid developer is stored. Method is used.

Also, conventionally, in a color-compatible electrostatic latent image developing apparatus in which an electrostatic latent image formed on an image support is developed by toner, which is a charged visualized particle, When supplying the color developer to the latent image surface of the support, a developer support corresponding to each of the yellow, magenta, cyan, and black developers is provided. By contacting the developer support corresponding to the yellow developer with the image support, the yellow developer is supplied to the latent image surface of the image support, and then, in a similar manner, A method of supplying a magenta, cyan, and black developer one after another to a latent image surface of an image support has been used.

However, in conventional large-size electrostatic recording devices, low-viscosity liquids are generally used in which toner is mixed with an organic solvent, Isopar G (registered trademark: manufactured by Exxon) at a ratio of about 1 to 2%. Developer is used.

However, in order to realize a safer and smaller liquid developing device by suppressing the generation of solvent vapor, it is preferable to use a liquid developer having a higher concentration than that used in conventional devices. Such a device has not been found in the past. Therefore, a high-concentration and high-viscosity liquid developer that supplies a small amount to the image support (toner is dispersed at a high concentration in an insulating liquid) High-viscosity liquid developer of 100 to 1000 OmPa · s), any method can be used to supply the liquid developer to the latent image surface of the image support. It is not clear whether is suitable.

Also, when multiple liquid developers are used for color printing, a conventional electrostatic latent image developing device requires a developer support for each developer, so the size of the device can be reduced. There was a problem that there was not.

Disclosure of the invention

The present invention has been made on the basis of the above circumstances, and is intended to reduce the thickness of a high-concentration, high-viscosity liquid developer applied on a developing agent support to be thin and uniform, thereby improving image quality. An electrostatic latent image that can supply a small amount of high-concentration and high-viscosity liquid developer uniformly to the latent image surface of the image support without causing toner to adhere to the non-image area of the support It is an object to provide a liquid developing device.

It is another object of the present invention to provide a small liquid developing device for forming a color image.

A liquid developing device for an electrostatic latent image according to the invention of the present application comprises a splitting means for applying a splitting liquid, which is a chemically inactive dielectric liquid having releasability, onto an image support. ,

A liquid developer with a viscosity of 100 to 100 OmPas in which toner is dispersed at a high concentration in a developer support and an insulating liquid in a thickness of 5 to 4 Coating means for applying the liquid developer to the surface, and applying the liquid developer through the developer support. Developing means for supplying to the surface of the image support;

It is characterized by having.

Further, it is preferable that the application means is a layer forming blade provided so as to abut on the developer support in the trail direction.

Furthermore, the application means may be at least two roller forces.

Further, the application means may be an application roller whose surface is covered with a sponge.

In addition, as a liquid developing device for an electrostatic latent image that forms a color image, an application unit includes a plurality of developer supply units that apply different liquid developers to the surface of the developer support, respectively. I like it.

According to the electrostatic latent image liquid developing apparatus of the present invention, a liquid developer in which toner is dispersed at a high concentration can be used because the liquid is applied to the image support. Thus, the amount of liquid can be made much smaller than that of a conventional low-concentration liquid developer. When the viscosity of the liquid developer exceeds 1000 mPas, it becomes difficult to stir the insulating liquid and the toner, and how to make the liquid developer is difficult. It is a problem. As a result, a liquid developer of 100,000 mPas or more is no longer suitable in terms of cost and is not realistic. On the other hand, when the toner concentration is less than 100 mPa · s, the toner concentration becomes lower and the toner dispersibility deteriorates, so that the developer can be developed in a thin layer. It disappears. Liquid development The layer thickness of the agent must be thin when the toner concentration is high and thick when the toner concentration is low. Also, the higher the viscosity, the thinner it needs to be. However, if the layer thickness of the liquid developer is more than 40 m, excessive toner adheres and image noise occurs. On the other hand, if the layer thickness is less than 5 / zm, unevenness will occur when a solid black image is output.

The liquid developing device for an electrostatic latent image according to one embodiment of the present invention is provided with a layer forming blade such that a front end portion thereof comes into contact with a developer support in a trail direction. Since the layer thickness of the high-viscosity liquid developer applied on the body can be regulated thinly and uniformly, a small amount of the liquid developer can be uniformly supplied to the latent image surface of the image support. it can.

Also, another electrostatic latent image liquid developing apparatus of the present invention in which the developing means supplies the liquid developer to the developer support via at least two rollers, is provided on the developer support. Since a high-concentration and high-viscosity liquid developer can be applied thinly and uniformly, a small amount of the liquid developer can be uniformly supplied to the latent image surface of the image support. The present invention further employs a developing means for applying a high-concentration and high-viscosity liquid developer to a developer support by an application roller having predetermined values of sponge thickness, porosity, and pore diameter. Another liquid developing device can apply a small amount of liquid developer to the developer support thinly and evenly, and therefore, it is necessary to contact the developer support with the image support. Therefore, a small amount of high-concentration and high-viscosity liquid developer can be uniformly supplied to the latent image surface of the image support. Further, another liquid developing device for an electrostatic latent image of the present invention is a developer support for supplying a color liquid developer to a latent image surface of an image support, and a liquid developer for a color on the developer support. Since a developing means having a plurality of color liquid developer supplying means for supplying the liquid developer is used, only one developer support is required, so that the size of the apparatus can be reduced. In addition, by using the developer support formed of a flexible and conductive thin plate-shaped member, the liquid developer layer formed on the developer support and the image support are formed on the image support. It is possible to disperse the contact pressure at the time of contact with the formed split liquid layer. For this reason, the liquid developer layer and the preset liquid layer can be brought into contact with each other in the developing process while maintaining a two-layer state, and at the end of the developing process, the inside of the preset liquid layer can be maintained. The separation between the two prevents the liquid layer of the pre-wet from being disturbed, thus preventing toner from adhering to non-image portions on the image support and disturbing the image. the viscosity of the insulation liquid to the liquid developing unit of an electrostatic latent image this and can be present invention for the 0. 5~ 1 0 0 O m P a · s, an electrostatic resistance ¹ 0 1 ² Q cm or more, the surface When a liquid developer having a tension of 21 dynZcm or less and a boiling point of 100 ° C or more is used, a high-viscosity liquid developer can be obtained. Since the liquid developer formed on the developer support is formed in a thin layer, the amount of insulating liquid contained in the liquid developer layer is extremely small, and is supplied to the latent image surface of the image support. Liquid developer The insulating liquid contained therein is also very small. Therefore, the amount of insulating liquid absorbed by paper or the like at the time of transfer is extremely small. Does not occur. However, if the viscosity is less than 0.5 mPa · s, the volatility will increase, and it is not appropriate because it is subject to laws and regulations as a dangerous substance. If the insulating liquid has a boiling point of less than 100 ° C, the amount of evaporation will increase, so there is a problem with the method of storing the developer, and the entire device must be sealed. It will also be difficult to improve the environment. When the electric resistance ing below ¹ 0 1 ² Ω cm, the insulating Ri is Do rather poor, preparative toner conductivity problems Ri becomes rather unable used as a developer to put. Therefore, it is desirable that the electric resistance be as high as possible. If the surface tension is more than 21 dyn / cm, the wettability will be poor and the familiarity with the pre-wiring solution will be poor. Therefore, it is desirable that the surface tension be as low as possible.

When the liquid developer contains toner having an average particle size of 0.1 to 5_im at a concentration of 5 to 40%, it is possible to obtain a liquid developer in which the toner is dispersed at a high concentration in an insulating liquid. I can do it. In addition, the resolution is improved substantially in inverse proportion to the toner particle size. Normally, the toner is present as a mass of about 5 to 10 pieces on the printed paper, so that when the average particle diameter of the toner is 5 / m or more, the resolution is reduced. become worse. On the other hand, when the average particle diameter of the toner is 0.1 m or less, the physical adhesive strength increases, and the toner is hardly transferred during transfer. It is difficult to remove the corner.

Pli © We Tsu preparative liquid, viscosity 0. 5 ~ 5 m P a · s, electric resistance ¹ 0 1 ² Ω cm or more, a boiling point of 1 '0 0 ~ 2 5 0 ° C, surface tension Is less than 21 dynZcm, a pleat solution that has releasability and has good insulating properties is absorbed by paper or the like during transfer. Must be evaporated during settling. For this reason, the viscosity is desirably 0.5 to 5 mPa · s in order to easily evaporate. If the viscosity is 5 mPa · s or more, evaporation becomes difficult, and if the viscosity is 0.5 mPa · s or less, volatility increases. If the boiling point is lower than 100 ° C, the amount of evaporation increases, so there is a problem in the method of storing the split solution.The entire device must be sealed and the working environment must be reduced. It will also be difficult to improve. On the other hand, if the boiling point is more than 250 ° C, the paper will curl during fixing and cannot be used, and high energy for heating will be required, resulting in higher costs. When the electrical resistance is less than or equal to ¹ 0 1 ² Ω cm, the insulating Ri is Do rather than evil, become rather unable used as a Prin c or falling edge of door solution. Therefore, it is desirable that the electric resistance value be as high as possible. If the surface tension is more than 21 dynZcm, the wettability will be poor, and the familiarity with the liquid developer will be poor. Therefore, it is desirable that the surface tension be as low as possible.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a liquid developing device for an electrostatic latent image according to an embodiment of the present invention. It is a schematic block diagram of a device.

FIG. 2 is a schematic perspective view of a splitting device used in the electrostatic latent image liquid developing device according to the present embodiment.

3A to 3F are views for explaining the operation of the electrostatic latent image liquid developing apparatus according to the present embodiment.

4 (A) and 4 (B) are diagrams for explaining the operation of the preset device shown in FIG.

FIG. 5 is a diagram illustrating the flow of the preset liquid when the preset liquid supply member is brought into contact with the photoconductor.

FIG. 6 is a diagram for explaining the entire development process. FIG. 7 is a diagram showing a state of the approach process.

FIG. 8 is a diagram showing a state of the toner moving process. FIG. 9 is a diagram illustrating a separation process of a non-image portion.

FIG. 10 is a diagram showing the separation process of the image part.

FIG. 11 is a diagram for explaining the significance of thinning the liquid developer.

FIG. 12 is a diagram showing a state in which the developing roller and the photoconductor are hard-contacted.

FIG. 13 is a diagram for explaining the soft contact of the electrostatic latent image liquid developing device according to the present embodiment.

FIG. 14 is a schematic diagram of a developing device used in the electrostatic latent image liquid developing device according to the present embodiment.

FIG. 15 is a view showing a modification of the developing device used in the electrostatic latent image liquid developing device according to the present embodiment.

FIG. 16 is a view showing a liquid of an electrostatic latent image according to the second embodiment of the present invention. It is a schematic structure figure of a body development device.

FIG. 17 is a schematic view of a developing device used in the electrostatic latent image liquid developing device according to the second embodiment.

FIG. 18 is a view showing a modification of the developing device used in the electrostatic latent image liquid developing device according to the second embodiment.

FIG. 19 is a schematic configuration diagram of a liquid developing device for an electrostatic latent image according to a third embodiment of the present invention.

FIG. 20 is a schematic diagram of a developing device used in a liquid developing device for an electrostatic latent image according to the third embodiment.

FIG. 21 is a schematic view of a coating roller used in the developing device shown in FIG.

FIG. 22 is a schematic diagram of a developing device used in a liquid developing device for an electrostatic latent image according to another embodiment of the third embodiment of the present invention.

FIG. 23 is a view showing a modification of the developing device used in the liquid developing device for electrostatic latent images according to the third embodiment of the present invention. FIG. 24 is a fourth embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a liquid developing device for an electrostatic latent image.

FIG. 25 is a schematic view showing another embodiment of the electrostatic latent image liquid developing apparatus according to the fourth embodiment of the present invention.

FIG. 26 is a schematic view of a liquid developing apparatus for an electrostatic latent image according to still another embodiment of the fourth embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram of an electrostatic latent image in a liquid developing apparatus according to an embodiment of the present invention, and FIG. 2 is an electrostatic latent image according to the embodiment. FIG. 3 is a schematic perspective view of a preset device used in the liquid developing device of FIG. 2, FIG. 3 is a diagram for explaining the operation of the electrostatic latent image liquid developing device of the present embodiment, and FIG. Fig. 5 is a diagram for explaining the operation of the preset device shown in Fig. 5. Fig. 5 shows the flow of the preset solution when the preset solution supply member is brought into contact with the photoconductor. FIG. 14 is a schematic view of a developing device used in the electrostatic latent image liquid developing device according to the present embodiment.

As shown in FIG. 1, an electrostatic latent image liquid developing device 1 according to an embodiment of the present invention includes a photosensitive member 10 serving as an image support, and a split liquid on a photosensitive member 10. A pre-wetting device 20 for applying a photoconductor, a charging device 30 for charging the photoconductor 10, an exposure device 40 for exposing an image on the photoconductor 10, and a static photoconductor 10. A developing device 50 for developing the electrostatic latent image by supplying toner to a portion where the electrostatic latent image is formed, and transferring the toner on the photoreceptor 10 to a predetermined sheet of paper. The apparatus includes a transfer device 60 for fixing and a cleaning device 70 for removing toner remaining on the photoconductor 10.

The charging device 30, the exposure device 40, the transfer device 60, the cleaning device 70, and the static eliminator 80 are almost the same as those used in conventional electrophotographic printers. Can be diverted to cases. Therefore, in the present embodiment, the description of the above-described devices will be omitted, and the split device 20 and the developing device 50 which are main parts of the present invention will be described.

As shown in FIG. 2, the splitting device 20 includes a photosensitive member. 10 A plate-like preset liquid supply member 202 having substantially the same length as the image width drawn on the top, and a case 200 for accommodating the preset liquid supply member 202 4, a tank 206 for storing the preset solution 220, and a pump 200 for pumping the preset solution 220 stored in the tank 206 And tubes 210a and 210b and a displacement device 211

A- ^ o

For the pre-jet liquid supply member 202, Beryu Isuzu (registered trademark: Kanebo Corporation) is used. Berry is a continuous porous sponge having a three-dimensional network structure in which pores are continuous, and can hold the pre-jet liquid 220 only by the volume of the pores, and has the volume of pores. When the pre-jet liquid 220 is supplied, the pre-jet liquid 220 is uniformly distributed in a direction perpendicular to the flow direction of the pre-jet liquid 220. Can be released. An opening is formed on the surface of the case 204 facing the photoconductor 10 so that the bottom surface of the pre-jet liquid supply member 202 can be brought into contact with the photoconductor 10. 2 0 4 a is provided. The tube 210a conveys the pre-jet liquid 220 pumped by the pump 208 to the supply side 202a of the pre-jet liquid supply member 202. I do. A space 204 b is formed between the supply side 202 a of the plumbing liquid supply member 202 and the case 204, and the plumbing liquid is supplied. After 220 is stored in the space 204b, it is supplied from the supply side 202a. Tube 210b is a pre-jet liquid supply member The pipette solution 220 discharged from the discharge side 202b of 202 is transported to the tank 206. When an external signal is not input, the displacement device 211 moves the split liquid supply member 202 away from the photoreceptor 10 as shown in FIG. 4 (A). Position, and when an external signal is being input, as shown in Fig. 4 (B), the preset liquid supply member 202 is brought into contact with the photoconductor 10 as shown in Fig. 4 (B). Let it.

As shown in FIG. 14, the developing device 50 stores a tank 502 storing a high-concentration and high-viscosity liquid developer 508 described later and a tank 502 storing a lower portion thereof. Developer supply roller 506 disposed so as to be immersed in the liquid developer 508, and a developer belt serving as a developer support disposed above the developer supply roller 506 5 10 and drive rollers 5 1 2 a, 5 for rotating the developing belt 5 10 and holding a part of the developing belt 5 10 in contact with the photoreceptor 10. A layer forming blade having a width substantially the same as that of the developing belt 510 provided so that the leading end thereof comes into contact with the developing belt 510 in the trail direction. 504 and a cleaning means such as a blade or a roller (not shown) for removing the liquid developer 508 adhered to the developing belt 510 after development.

The developer supply roller 506 conveys the liquid developer 508 to the surface of the developing belt 510 by rotating in a direction opposite to the rotation direction of the developing belt 510. Developer supply roller 5 for supplying liquid developer 508 to developer belt 5 10 As described later, in the present embodiment, a liquid developer 508 in which toner was dispersed at a high concentration was used, and thus a small amount of developer was used. This is because it is necessary to apply evenly to the surface.

The developing belt 510 is rotated in the opposite direction to the rotation direction of the photoconductor 10 by the drive rollers 512a and 512b512c, whereby the photoconductor 1 is rotated. Supply the liquid developer 508 applied to the surface of No. 0 through the developer supply port 506. The development belt 510 has a nickel-free nickel-belt and polyimi A flexible belt-shaped member such as a resin belt such as a film belt is used. This disperses the contact pressure when the liquid developer layer formed on the current belt 510 and the split liquid layer formed on the photoreceptor 10 come into contact with each other. As a result, the liquid developer layer formed on the developing belt 510 and the split liquid layer formed on the photoreceptor 10 can be distinguished from each other. It is possible to make a contact while maintaining a proper two-layer state, and to separate the two inside the split liquid layer.

The developing belt 510 must be capable of applying a developing noise. Therefore, when a resin belt is used, it is necessary to reduce the electric resistance value by adding conductive fine particles, or to conduct conductive processing on the surface of the belt. When the belt itself has conductivity, the drive rollers 51a, 51b, and 51c have conductive particles added so that a developing bias can be applied. Low resistance Rubber rollers are used. If the belt surface is subjected to conductive processing, a conductor that contacts the belt surface is provided, and a bias voltage is applied to this conductor. In addition, a perforation is provided at both ends of the developing belt 510, and this is combined with sprockets provided at both ends of the driving roller 512a. The developing belt 510 is driven to rotate. This makes it possible to drive the developing belt 510 stably.

The layer forming blade 504 regulates the layer thickness of the liquid developer 508 applied on the developing belt 510. In the layer forming blade 504, the protruding amount 1 of the leading end portion 504a is 10 to 10 from the contact position 504b of the layer forming blade 504 and the developing belt 510. It is desirable that it be provided so as to be 10. As will be described later, in the present embodiment, a high-viscosity liquid developer having a viscosity of 100 to 100 mPas was used, so that when the protrusion amount 1 was smaller than 10 m, If the layer thickness of the liquid developer 508 applied on the developing belt 510 cannot be controlled to be thin, on the other hand, if the protrusion amount exceeds 100 力 m, the liquid developer 5 08 ripples, making it impossible to uniformly regulate the layer thickness of the liquid developer 508 applied on the developing belt 510.

The layer forming blade is formed of rubber that does not swell in the insulating liquid used for the liquid developer. As will be described later, in this embodiment, silicon oil was used as the insulating liquid of the liquid developer 508, so that the layer forming blade 504 was made of silicon oil. Non-swelling silicone rubber, fluorosilicone rubber, fluorine rubber, urethane rubber, etc. are used.

The pressing force of the layer forming blade 504 on the developing belt 510 is 10 when the hardness of the rubber used for the layer forming blade 504 is 60 to 70 ° (JIS A). Desirably, it is 100 g / cm. In the present embodiment, the liquid developer 508 having a high viscosity was used, so that the pressing force was less than 10 g cm, and the liquid developer 508 applied on the developing belt 5 10 However, when the pressing force exceeds 100 g gcm, the liquid developer 508 undulates and the liquid applied on the development belt 5 10 The layer thickness of the developer 508 cannot be regulated uniformly. In order to obtain the above pressing force, the present inventors hold one end of the layer forming blade 504 with a holding plate 513 as shown in FIG. A fulcrum 513a was provided at the end holding the layer forming blade 504 of 513, and the other end of the holding plate 513 was pulled with a panel or the like. The strength of the panel is set so that the deflection t of the layer forming blade 504 becomes about 1 mm when the free length h force of the layer forming blade 504 is 15 mm. did.

Next, an image forming material used in one embodiment of the present invention will be described. The liquid developer 508 used in this example is a binder such as an epoxy resin, a charge control agent for giving a predetermined charge to the toner, a coloring pigment, and a dispersion for uniformly dispersing the toner. Toner and carrier liquid Become. The composition of the toner is basically the same as that used in the conventional liquid developer, but their formulations are compatible with silicone oil to adjust the charging characteristics and dispersibility. Has been changed. The smaller the average particle size of the toner, the better the resolution. However, the smaller the particle size, the greater the physical adhesive strength and the more difficult it is to peel off when transferring. For this reason, in the present embodiment, the average particle diameter of the toner is adjusted so that the center is about 2 to 4 zm for the purpose of improving transferability. It depends on the carrier liquid, resin, coloring pigment, charge control agent, etc. and their concentration. In this example, the experiment was performed by changing the viscosity in the range of 50 to 600 mPa · s and the toner concentration in the range of 5 to 40%. As the carrier liquid, use is made of a low-viscosity liquid such as dimethylpolysiloxane oil or cyclic polysiloxane oil exhibiting high electric resistance. Since the liquid developer layer formed on the developing belt 5 10 is formed in a thin layer, the amount of the carrier liquid contained in the liquid developer layer is extremely small. The amount of carrier liquid contained in the liquid developer supplied to the surface of the latent image is extremely small. Therefore, the amount of carrier liquid absorbed by paper or the like at the time of transfer is extremely small. If the viscosity is 100 mPa · s or less, almost no carrier liquid remains after fixing. I can't see it. According to experiments by the present inventors, the carrier liquid has a viscosity of 2.5.

Dow Corning U.S.A., which has mPas, DC 344, and Dow Corning U.S.A., which has a viscosity of 6.5 mPas When carrying out image output experiments using DC 345, no carrier liquid remained on the paper after fixing in any case.However, due to the high volatility, the developing device was sealed. Needs arise. In addition, the carrier fluid has a viscosity of 20

When performing an image output experiment using Shin-Etsu Silicon's 1 ^?-9 6-20 made of 111? 3 '5, the carrier liquid remaining on the paper after fixing was not observed. I couldn't. Also, since the volatility is not so high, it was not necessary to make the developing device a hermetically sealed structure. DC344, DC345, and KF-96-20 are commonly used in cosmetics and have high safety such as toxicity. There are many other types of carrier liquid, such as Shin-Etsu Silicone's KF 9337, and any type of liquid carrier that satisfies electrical resistance, evaporation characteristics, surface tension, safety, etc. May be selected.

Also, in experiments conducted by the inventors, if the surface tension is large, the image may become unclear or toner clumps may adhere.Experimentally, when the surface tension is 21 dyn / cm or more, It turns out that problems are likely to occur in image quality.

As for the electric resistance value, there is a problem of toner charging stability, and it is preferable that the electric resistance value be 10 ¹⁴ Ωcm or more. Minimum ¹ 0 1 ² Ω cm or more is required. In the description of the present embodiment, in view of these experimental results, an example using DC345, which is low in price and easily available, will be described.

The pre-wetting solution evaporates easily during fixing without disturbing the electrostatic latent image formed on the image support, and fog It is required that the lump does not adhere. Examples include DC344, DC200-0.65, —1.0, —2,0 from Dow Corning in the United States, and KF96 from Shin-Etsu Silicon. L-1 and KF 9 9 3 7 etc. In general, it is preferable to select silicon oil which has a high evaporating property.

In experiments conducted by the inventors, the liquid was dried by development, transfer, and fixing without any problem when the liquid viscosity was in the range of 0.5 to 3 mPa · s. It was found that at about 6 mPa · s, it took a little time and temperature to dry the liquid during fixing. At 10 mPa · s, the energy required for drying is too large and is not common. In addition, if it is less than 0.5 mPa · s, the volatility will be high, so it is not appropriate because it is treated as dangerous goods and subject to laws and regulations. Also, due to the effect of heating the paper, the boiling point is preferably 250 ° C or less.

The surface tension is preferably as low as possible in order to reduce the adhesive force between the developer and the image support, improve the releasability, prevent the image from being stained, and improve the resolution of the image quality. According to experiments performed by the present inventors, it is preferable to select an object having a lower limit of about 20 to 21 dynZcm.

If the electrical resistance is low, it leaks the latent image charge and blurs the image. Therefore, it is necessary to use the highest possible one. Experimentally correct desired than about ¹ 0 1 ⁴ Ω cm, minimum ¹ 0 1 ² Ω cm is required. Next, the operation of the electrostatic latent image liquid developing device according to one embodiment of the present invention will be described. First, as shown in FIG. 3A, the surface of the photoconductor 10 is charged by the charging device 30. Generally, a corona discharger is used for the charging device 30. Next, an image is exposed on the charged photoconductor 10. For example, an image is exposed by a laser scanner to form an electrostatic latent image on the surface of the photoconductor 10. As shown in Fig. 3B, the part irradiated by the laser scanner becomes conductive and loses its charge, and the part not exposed to the light becomes an electrostatic latent image that is an image of the charge. Remain.

Next, as shown in FIG. 3C, the above-described pre-wet solution 220 is applied onto the photoreceptor 10 by a pre-wet device 20. When a control signal is input from the outside, the split device 20 brings the bottom surface of the split liquid supply member 202 into contact with the photoreceptor 10. The pump liquid 208 constantly circulates the preset liquid 220 inside the preset liquid supply member 202, so that the preset liquid supply As shown in FIG. 5, the pre-pump liquid 220 that exceeds the volume of the pores of Veriyu, which is the member 202, is discharged from the pre-wet liquid supply member 202, as shown in FIG. 0 2b and also discharged from the bottom of the pre-jet liquid supply member 202 and are uniformly applied on the photoreceptor 10 without damaging the photoreceptor _10c Next, the electrostatic latent image is visualized by the developing device 50. The liquid developer 508 stored in the tank 502 is applied to the developing belt 510 by the developer supply roller 506. The liquid developer 508 applied to the developing belt 510 is thinned and uniformly regulated by the layer forming blade 504 so that the developing belt 51 The liquid developer layer formed on the surface of the photoconductor 10 is brought close to the electrostatic latent image formed on the surface of the photoconductor 10 as shown in FIG. The toner is moved onto the photoconductor 10 to form a toner image. The liquid developer 508 stored in the tank 502 is agitated by the rotation of the developer supply roller 506. Next, as shown in FIG. The toner image on the photoreceptor 10 is transferred to a predetermined paper 604 by an electrostatic force generated by a voltage applied to the transfer roller 60, for example, the transfer roller 602. Although not shown in FIG. 1, as shown in FIG. 3F, as shown in FIG. 3F, the sheet is formed on paper 604 by a fixing heater 704 provided in a fixing roller 700 of the fixing device. The transferred toner is melted thermally and fixed to paper 604. On the other hand, the liquid developer 508 remaining on the photoreceptor 10 is removed by the cleaning device 70. The photoreceptor 10 is subjected to charge elimination by a charge eliminator (not shown) and then used again in the above-described cycle from charge to charge elimination.

6 to 10 are diagrams for explaining in detail the developing process of one embodiment of the present invention, and FIG. 6 illustrates the whole of the developing process. FIG. 8 is a diagram illustrating a toner moving process, FIG. 9 is a diagram illustrating a non-image portion separation process, and FIG. 10 is a diagram illustrating an image portion separation process. Unlike the conventional development process, As shown in Fig. 6, the developing process involves the approaching process in which the developing belt approaches the photoreceptor and the liquid developer approaches the photoreceptor surface, and the liquid developer layer and the split liquid layer form a soft solution. The toner transfer process in which the toner moves as a result of the foot contact, and the separation process in which the developing belt separates from the photoconductor and adheres to the developing belt and the toner adheres to the photoconductor. It is thought that it consists of three processes.

In the approaching process, as shown in FIG. 7, the developing belt 5100 is made of a flexible member, so that the minute distance between the developing belt 510 and the photoconductor 10 is minimized. That is, a gap d is formed, and the high-viscosity liquid developer composed of the carrier liquid and the toner and the plug liquid are soft-contacted, whereby the viscosity is low. The preset liquid is slightly pushed back and forth, and a pool of the preset liquid is generated.

In the toner moving process, as shown in FIG. 8, in the image area, toner is mainly cooled by an electric field formed between the charge on the photoreceptor 10 and the developing belt 5 10. It moves to the latent image surface by passing through the pre-wet liquid layer due to the force of the spring. On the other hand, the toner in the non-image area is basically a photoconductor of unnecessary toner because the surface of the photoconductor 10 and the liquid developer layer are separated by a pre-wet liquid layer. No adhesion to the surface of 10 occurs.

In the separation process, the liquid developer basically remains on the developing belt 510 in the non-image area as shown in FIG. At the interface between the pre-wet liquid layer and the liquid developer layer, two layers When the liquid is separated, a part of the low-viscosity split liquid layer is transferred to and separated from the liquid developer layer. Therefore, the separation point between the two layers is considered to be inside the prewet liquid layer. On the other hand, in the image area, as shown in Fig. 10, the toner moved to the surface of the photoreceptor 10 displaces the pre-wet liquid layer, so that the pre-wet liquid layer becomes the toner. Located on a layer and separates within that layer. On the developing belt 510, a part of the carrier liquid and a part of the preset liquid form after the toner moves to form a layer. The pre-jet liquid remaining on the photoreceptor 10 facilitates the transfer by the electrostatic force of the toner in a subsequent transfer process.

FIG. 11 is a diagram for explaining the significance of thinning the liquid developer. If the liquid developer layer applied on the developing belt 5 10 is too thick, the viscosity of the liquid developer 5 08 is high. The toner group moving to the surface forms a cluster without breaking the adhesive strength to the toner located therearound, and moves to the surface of the photoconductor 10. Overtoning of toner occurs, causing image noise. In order to suppress the occurrence of this cluster, it is necessary to keep the liquid developer thickness at a minimum value that allows sufficient development.

FIG. 12 is a diagram showing a state in which the developing roller serving as the developer support and the photoconductor are contacted one by one, and FIG. 13 is a diagram showing the soft contact of the present embodiment. FIG. As described above, in the developing process of this embodiment, The function of the pre-jet liquid layer related to image formation is important. Therefore, an important requirement in the development process is to maintain the state of the two layers of the pre-liquid solution layer and the liquid developer layer. If the developing roller and the photoconductor are hard-contacted as shown in FIG. 12, the two-layer state cannot be maintained, so in this embodiment, as shown in FIG. 13. By using a developing belt 510 made of a flexible member as a developer support, the surface of the photoconductor 10 on which the electrostatic latent image is formed is developed. A small gap d is formed between the belt 5 and the belt 5.

Next, optimization of the layer thickness of the liquid developer layer, the layer thickness of the split liquid layer, and the developing gap will be described. The layer thickness of the liquid developer layer must be thinner when the viscosity of the liquid developer is 50 mPa · s or more, especially when it is 50 OmPas or more. Ideally, the thickness is a little thicker than the layer thickness that satisfies the toner development amount required during development (that is, the density of the solid portion). This is because when a liquid developer with a high viscosity is used, during development, the toner selected electrostatically moves over the photoconductor by pulling extra toner due to the viscosity of the liquid. As a result, abnormal adhesion of toner occurs, causing image stains. In experiments conducted by the inventors, a good image was obtained with a liquid developer having a high toner concentration at a layer thickness of about 5 μm to 40 μm at a low toner concentration. When a liquid developer having a toner concentration of 20 to 30% is used, the layer thickness of the liquid developer is However, good image quality was obtained at about 20 m.

There is an optimum value for the thickness of the pre-out liquid layer depending on the viscosity and surface tension of the selected pre-out liquid. If it is too thin, the high-viscosity liquid developer adheres irregularly on the photoreceptor, causing image stains. As the amount of the pre-wetting solution is increased, the image stain is improved and the optimum value is confirmed. As the amount is further increased, the charge of the latent image tends to flow and the sharpness and the resolution tend to decrease, and the toner tends to flow during development and the image tends to blur. In experiments using DC344, good results were obtained with a thickness of 5 to 30 m. For less viscous materials, good results can be obtained with thinner or thicker materials. However, for higher viscosities, the optimal values tend to be narrower.

The narrower the gap between the photoreceptor and the developing belt, the better the resolution and the uniformity of the density of the solid part in image quality are the same as the conventional developing method. The high-viscosity liquid developer used in the present embodiment has a strong cohesive force between toners, and, like a powder developer, is not subject to mechanical shock and static electricity from a developer support or carrier particles. No development occurs in which toner released by force is used for development. That is, development is not performed with an air layer interposed between the liquid developer layer and the photoconductor. <Therefore, the development belt and the liquid developer layer, the liquid developer layer and the print liquid layer, It is essential that the photoreceptor layer and the photoreceptor are in contact with each other. According to Therefore, the developing gap d must be smaller than the thickness of the liquid developer layer and the thickness of the pre-wet liquid layer so as not to disturb each layer. In the present embodiment, the liquid developer is set between 80 μm and 50 m according to the difference in viscosity and toner concentration.

Table 1 shows the results of image extraction and experiments performed under the above conditions. From these results, the optimum range of the viscosity of the developing agent and the splitting solution for the developing method of the present embodiment is as follows. s, the preyt hydraulic power was found to be between 0.5 mPa's and 5 mPa's. The image quality varies depending on the thickness of the liquid developer layer on the developing belt, the thickness of the split liquid layer, the developing gap, etc. Even after the modification, the tendency was almost as shown in Table 1, and it was confirmed that the optimal region of the liquid developer was within the range shown in Table 1. The silicone oil for the pre-wetting solution was DC 200 series manufactured by Dow Corning, and the carrier solution for the developing solution was manufactured by the same company. DC 345 was used.

[Table 1] Viscosity of pre-wet liquid (m Pa · s)

(mPa toner

-s) Concentration 0.65 1.5 3.0 5.0 10

(%)

50 5 Image density tends to be low, toner

Dispersion stability of

100 10 Slightly lower concentration

Current trend

Image Remains on paper

Liquid 500 20 Evaporation of the oil that has been ί> tea i rC TO viscous ιοορ 22 is slow. Practical degree Both density and resolution are practical

2000 25 The limit of good image quality. O

O

3000 30

6000 40 According to the present embodiment, since the layer forming blade 504 is provided so that the front end portion abuts on the developing belt 510 in the trail direction, the developing belt 510 Since the layer thickness of the high-viscosity liquid developer 508 applied to the surface of the photoconductor 10 can be regulated to be thin and uniform, a small amount of the liquid developer 508 can be uniformly applied to the latent image surface of the photoconductor 10. Can be supplied.

Further, according to the present embodiment, the layer forming blade 5 is formed such that the leading end 504a projects from the contact position 504b of the developing belt 510 by 10 to 100 / m. With the provision of 04, it is possible to prevent the liquid developer 508 applied on the current belt 510 from rippling.

Further, according to the present embodiment, the layer forming blade 504 is formed of a rubber which does not swell in the insulating liquid used for the liquid developer 508, so that the developing belt 510 is formed. The layer thickness of the liquid developer 508 applied on top can be kept constant.o

Further, according to the present embodiment, the use of silicone oil as the carrier liquid for the liquid developer has the following advantages over the conventional one by using silicon oil.

Conventional liquid developers are generally used as carrier liquids.

IsoparG (registered trademark: manufactured by Exxon) is used. Since the resistance value of this isopar is not as high as that of silicone oil, the toner chargeability is deteriorated when the toner concentration is increased, that is, when the distance between the particles is reduced. Therefore, in the case of Isopar, the toner concentration is limited. On the other hand, The silicon oil used in the examples has a sufficiently large resistance value, so that the toner concentration can be increased. In general, in the case of Isopar, the toner is in a good dispersion state. Therefore, even when the toner concentration is 1 to 2%, the toners repel each other, so that the toner is uniformly dispersed. On the other hand, when the toner concentration is 1 to 2%, silicone oil does not have good dispersibility and precipitates soon. However, when the toner concentration is set to 5 to 40%, the particles are densely packed and stably dispersed. For this reason, in this embodiment, a high-viscosity liquid developer in which toner is dispersed at a high density is used. As a result, the amount of the developing solution can be greatly reduced as compared with the conventional low-concentration liquid developer, and the size of the apparatus can be reduced. Furthermore, since the liquid developer of this embodiment is a high-viscosity liquid, storage and handling are easier than conventional low-viscosity liquid developers and powder developers.

As described above, Isopar, which has been used in conventional liquid developers, has high volatility and emits a bad smell, which not only deteriorates the working environment but also causes pollution. Was. On the other hand, the silicone oil used in this example is a safe liquid and odorless, as is clear from the fact that it is used for cosmetics. However, according to this embodiment, the working environment can be improved, and no pollution problem occurs.

The first embodiment of the present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the gist. For example, in the above embodiment, the developing device using the developing belt 510 formed of a flexible belt-like member on the developer support has been described as the developing device. The present embodiment is not limited to this. For example, as shown in a developing device 52 shown in FIG. 15, a developer support is formed by a conductive member such as a metal roller or an elastic roller. The developing roller 520 may be used. However, the liquid developer layer formed on the developing roller 520 and the pre-jet liquid layer formed on the photoreceptor are brought into contact while maintaining a two-layer state, and both are pressed. In order to separate the liquid inside the wet liquid layer, the developer port ラ is arranged so that a minute gap d is formed between the developing roller 520 and the photoconductor. It is necessary to use a photosensitive velvet made of a flexible belt-like member for the photosensitive body.

Further, in the above-described embodiment, the case where the liquid developer 508 is applied to the developing belt 510 using the developer supply roller 506 has been described, but the present embodiment is not limited to this. It is not something. Instead of the developer supply roller, for example, the liquid developer may be pumped up by a double gear pump provided by being immersed in the liquid developer stored in the tank and applied to the developing belt. Alternatively, the liquid developer may be applied to the developing belt by a bellows pump that stores and discharges the liquid developer.

Next, a second embodiment of the present invention will be described with reference to FIGS. FIG. 16 is a schematic configuration diagram showing a configuration of a liquid developing device for an electrostatic latent image according to a second embodiment of the present invention. FIG. 17 is a schematic diagram of a developing device used in the liquid developing device. FIG. 18 is a view for explaining a modification of the developing device. Here, the same reference numerals in the figure are used for those having the same functions as in the first embodiment.

As shown in FIG. 16, a liquid developing device 1 for electrostatic latent images according to a second embodiment of the present invention includes a photoconductor 10 as an image support and a pre-printed photoconductor 10 on the photoconductor 10. A pre-jet device 20 for applying a liquid jet, a charging device 30 for charging the photoconductor 10, an exposure device 40 for exposing an image on the photoconductor 10, and a photoconductor 10. A developing device 50 that visualizes the electrostatic latent image by supplying toner to a portion where the electrostatic latent image is formed, and transfers the toner on the photoconductor 10 to predetermined paper. The image forming apparatus further includes a transfer device 60 for performing fixing and fixing, and a cleaning device 70 for removing toner remaining on the photoconductor 10.

The difference between the liquid developing device for electrostatic latent images of the second embodiment and the liquid developing device of the first embodiment is a developing device 50, so that the description of the other portions is omitted, and the developing device 50 explain in detail.

As shown in FIG. 17, the developing device 50 of this embodiment stores a tank 502 storing a high-concentration and high-viscosity liquid developer 508 and a tank 502 storing the high-concentration and high-viscosity liquid developer 508. The supply roller 504 provided at the supply port of the tank 502 for supplying the liquid developer 508 and the liquid developer supplied by the supply roller 506 are supplied. A regulating blade 505 for regulating the amount of liquid, a developing belt 510 serving as a developer support, and a rotating part of the developing belt 510 and a part of the developing belt 510 being a photoconductor. Drive rollers 5 1 2 a, 5 1 2 b, 5 1 2 c that are held in contact with 10, and coating rollers 5 that apply liquid developer 5 08 to development belt 5 10 , A transport roller 514 a, 514 b for transporting the liquid developer 508 supplied by the supply roller 506 to the application roller 506, and a developing belt 5. Adjusting rollers 516a and 516b for adjusting the liquid amount of liquid developer 508 applied to 10 and liquid developer 508 adhering to developing belt 510 after development are applied. A removal blade 5 17 for removal is provided.

The supply roller 506, the application roller 506, and the transport rollers 514 a and 514 b are provided with irregularities of 10 to 50 m on the surface thereof. By holding and transporting the liquid developer 508 in these concave portions, it is possible to prevent the liquid developer 508 from waving.

The supply roller 506 is disposed so as to be in contact with the transport roller 514a, and the tank is rotated by rotating in a direction opposite to the rotation direction of the transport roller 514a. The liquid developer 508 stored in 502 is transported to the transport rollers 514a. The regulating blade 505 is disposed so as to contact the supply roller 506 in the trail direction. As a result, the liquid developer 508 adhered to the convex portion of the surface of the supply roller 506 is removed, and is held by the concave portion of the surface of the supply roller 506. And transports only the liquid developer 508 to the transport rollers 514a. In addition, a liquid pool of the liquid developer 508 is formed on the contact start side of the contact portion between the supply roller 506 and the transport roller 514a. Thereby, the liquid developer 508 to be conveyed to the conveyance roller 514 a is adjusted to be constant and uniform.

The transport roller 514a is disposed so as to be in contact with the transport roller 514b, and is rotated in a direction opposite to the rotation direction of the transport roller 514b. Transports the liquid developer 508 supplied by the supply roller 506 to the transport roller 511.

Transport to 4b. In addition, a liquid pool of the liquid developer 508 is formed on the start side of the contact portion between the transport rollers 514a and the transport rollers 514b. As a result, the liquid developer 508 transported to the transport roller 514 b is adjusted to be constant and uniform. The transport roller 514 b is disposed so as to contact the application roller 506, and is rotated in a direction opposite to the rotation direction of the application roller 550, so that the transport roller 514 b is rotated. The liquid developer 508 supplied by the 514a is conveyed to the application roller 506. In addition, a liquid pool of the liquid developer 508 is formed on the contact start side of the contact portion between the transport roller 5 14 b and the application roller 5 0 60. Adjust so that the amount of the liquid developer 508 to be conveyed to 060 is constant and uniform. The liquid pool formed between the openings becomes smaller as the distance from the application roller increases. The application roller 506 is arranged so as to be in contact with the developing belt 510, and is rotated in a direction opposite to the rotation direction of the developing belt 510, so that the conveying roller is rotated. Apply the liquid developer 508 supplied from 514 b to the surface of the developing belt 510. As will be described later, since an elastic roller is used for the application roller, a liquid pool is not formed between the application roller 506 and the developing knurled 510 so that the image forming bell is not formed. G 5 10

The use of the supply roller 506, the application roller 506, and the transport rollers 514 a and 514 b to supply the liquid developer 508 to the development belt 510 will be described later. As described above, in this embodiment, the liquid developer 508 in which toner is dispersed at a high concentration was used, so that a large amount of the developer was not required, and a small amount of the liquid developer was used. The reason is that it is only necessary to apply evenly and thinly to the surface of the 510. In this embodiment, the peripheral speeds of the supply port roller 506, the application roller 506, and the transport rollers 514a and 514b are the same as the peripheral speed of the developing belt 510. It was set to be. According to an experiment conducted by the present inventors, a small amount of liquid developer can be obtained by rotating the conveying rollers 514a and 514b at a speed different from the peripheral speed of the developing belt 510. It has been found that 508 can be applied evenly and thinly to the surface of the developing belt 5110. The adjusting roller 516a is disposed so as to be in contact with the conveying roller 514b, and rotates in a direction opposite to the direction of rotation of the conveying roller 514b. As a result, the adjustment roller 5 1 A liquid reservoir of the liquid developer 508 is formed on the contact start side of the contact portion between the transfer roller 6a and the transport roller 514b. In this way, the transport roller 514 b adjusts the liquid developer 508 to be supplied to the application roller 506 so as to be uniform and constant. The adjusting roller 516 b is disposed so as to be in contact with the application roller 506, and rotates in a direction opposite to the rotation direction of the application roller 506. As a result, a liquid pool of the liquid developer 508 is formed on the contact start side at the contact portion between the adjusting roller 516b and the application roller 506. In this way, the application roller 5006 adjusts the liquid developer 508 to be supplied to the developing belt 5110 so as to be constant and uniform.

The supply roller 506, coating roller 506, transport roller 514a, 514b, and adjustment roller 516a, 516b include rigid rollers such as metal rollers and resin rollers. Other Elastic rollers such as a sponge roller or a rubber roller of closed cell or open cell are used. However, the application roller 506 is used to apply the liquid developer 508 to the development belt without causing a liquid pool between the application roller and the development belt 510. An elastic roller is used. In particular, it is not preferable to use a metal roller for the application roller in order to prevent the surface of the developing belt 5 10 from being damaged. The supply roller 506, the application roller 506, the transport rollers 514a and 514b, and the adjusting rollers 516a and 516b carry the liquid developer 508. Swells into silicone oil It must not do anything. Therefore, when a single-cell or open-cell sponge roller is used, it is necessary to cover the surface of the roller with Teflon, nylon, or the like. When a rubber roller is used, it is necessary to use rubber that does not swell in silicone oil.

The developing belt 510 is rotated in the opposite direction to the rotation direction of the photoconductor 10 by the driving rollers 512a and 512b: 512c. The liquid developer 508 applied to the surface of the photoreceptor 10 by the application roller 506 is conveyed. The developing belt 510 is made of a flexible member such as a resin belt such as a nickelless nickel belt or a polyimide film belt. This disperses the contact pressure when the liquid developer layer formed on the developing belt 510 and the print liquid layer formed on the photoreceptor 10 come into contact with each other. Therefore, the liquid developer layer formed on the developing belt 510 and the pre-jet liquid formed on the photoreceptor 10 are brought into contact with each other while maintaining a two-layer state, And both can be separated inside the pre-wet liquid layer o

The developing belt 510 must be capable of applying a developing bias. Therefore, when a resin belt is used, it is necessary to reduce the electric resistance value by adding conductive fine particles, or to conduct a conductive process on the surface of the belt. When the belt itself has conductivity, a developing noise can be applied to the drive rollers 51 a, 51 b and 51 c. A rubber roller with a low electric resistance value, to which conductive fine particles are added, is used. If the belt surface has been subjected to conductive processing, a conductor that contacts the belt surface is provided, and a bias voltage is applied to this conductor.

Next, the operation of the electrostatic latent image liquid developing device according to the second embodiment of the present invention will be described.

In the liquid developing device for an electrostatic latent image of the second embodiment, as in the first embodiment, an electrostatic latent image is formed on the surface of the photoreceptor 10 and the pre-wet liquid is applied. Then, the electrostatic latent image is visualized by the developing device 50. The liquid developing agent 508 stored in the tank 502 is supplied by the supply roller 506, and thereafter, is applied via the conveyance rollers 514a and 514b.

It is transported to 506. The liquid developer 508 conveyed to the application roller 506 via a plurality of rollers in this way is applied to the development belt 510 thinly and without unevenness, and the development belt 511 is applied. 0 Form a thin layer on top. The liquid developer 508 supplied to the developing belt 510 is supplied to the adjusting rollers 516a, 51

It is adjusted so that it is always constant and uniform with 6b.

Next, the liquid developer layer formed on the developing belt 5100 is brought close to the electrostatic latent image formed on the surface of the photoreceptor 10 as shown in FIG. Then, the charged toner is moved onto the photoconductor 10 to form a toner image.

Thereafter, the transfer and fixing of the toner image are performed according to the same steps as in the liquid developing device of the first embodiment. According to the second embodiment of the present invention, an application roller 506 for applying the liquid developer 508 to the developing belt 510 and the liquid developer 5 stored in the tank 502 are provided. Supply roller 506 for supplying '08 and liquid developer 508 supplied by supply roller 506 are applied. Π-Transport port 5 for transport to roller 506 The use of the developing device having 14a and 514b allows the liquid developer 508 to be applied to the developing belt 510 thinly and evenly. In addition, a small amount of liquid developer can be uniformly supplied to the latent image surface of the photoreceptor 10. According to this embodiment, the adjusting rollers 5 16 a and 5 16 b are respectively connected to the transport rollers 5. 14 b, the use of the developing device in contact with the coating roller 5 0 6 0 10, the contact between the adjustment roller 5 16 a and the transport roller 5 14 b Contact start side and adjustment roller A liquid reservoir of the liquid developer is formed on the contact start side of the contact portion between the coating roller 5 16 b and the coating roller 5 0 6 0, whereby the latent image on the photoreceptor 10 is formed. A fixed amount of liquid developer can be uniformly supplied to the surface.

The present embodiment is not limited to this embodiment, and various modifications are possible within the scope of the invention. For example, in the present embodiment, as a developing device, the liquid developer 508 supplied by the supply roller 506 is applied to the coating roller 5 via the transport rollers 514a and 514b. A description has been given of a case in which the developer is supplied to the developing belt 510 after being supplied to the developing device 600. However, the present embodiment is not limited to this, and the developing device uses a small amount of liquid developer. Both to the development belt via two rollers Anything can be supplied. Therefore, the liquid developer supplied from the supply roller may be directly supplied to the application roller and then applied to the developing belt, or one of the liquid developer discharged from the discharge port roller may be used. Alternatively, the developer may be supplied to the application roller via three or more transport rollers, and then applied to the developing belt.

Also, in the present embodiment, the developing device in which the adjusting rollers 5 16 a and 5 16 b are brought into contact with the transport roller 5 14 b and the coating port — roller 5 06, respectively, has been described. The present embodiment is not limited to this, and the adjusting roller is provided according to the thickness of the liquid developer layer formed on the developing belt 510. It is not necessary to install them if not necessary. Further, the means for applying the liquid developer to the transport roller is not limited to the discharge roller, but may be, for example, a means for applying the liquid developer to the transport roller by a bellows pump.

Further, in the present embodiment, the developing device in which the liquid developer 508 adhered to the developing belt 510 is removed by the removing blade 517 has been described. The invention is not limited to this, and the liquid developer 508 adhered to the developing belt 510 is applied to the developing belt 510 as in a developing device 52 shown in FIG. It may be removed by a scraping roller 519 arranged in contact with the sheet.

Next, a third embodiment of the present invention will be described with reference to FIGS. FIG. 19 is a schematic configuration diagram showing a configuration of a liquid developing device for an electrostatic latent image according to a third embodiment of the present invention. FIG. 20 is a schematic diagram of a developing device used in the liquid developing device. 21 is a schematic view of a coating roller used in the developing device, and FIGS. 22 and 23 are diagrams illustrating a modification of the developing device. Here, the reference numerals in the figure are the same as those in the second embodiment for members having the same functions.

As shown in FIG. 19, a liquid developing device 1 for electrostatic latent images according to a third embodiment of the present invention includes a photosensitive member 10 serving as an image support and a pre-adhesive member on the photosensitive member 10. A presetting device 20 for applying a setting solution, a charging device 30 for charging the photoreceptor 10, an exposing device 40 for exposing an image on the photoreceptor 10, and a photoreceptor 10. A developing device 50 that visualizes the electrostatic latent image by supplying toner to a portion where the electrostatic latent image is formed, and transfers the toner on the photoconductor 10 to predetermined paper. The image forming apparatus further includes a transfer device 60 for performing fixing and fixing, and a cleaning device 70 for removing toner remaining on the photoconductor 10.

The difference between the liquid developing device for electrostatic latent images of the third embodiment and the liquid developing device of the second embodiment is that the liquid flows from the liquid developer storage tank 502 of the developing device 50 to the developing belt 501. Since it is a mechanism for supplying the developer 508, the description of the other parts will be omitted, and the mechanism of the developing device 50 will be described in detail.

As shown in FIG. 20, the developing device 50 of the third embodiment has a tank 50 for storing a high-concentration and high-viscosity liquid developer 508. 2, a supply roller 504 which is disposed by being immersed in the liquid developer 508 stored in the tank 502, and a supply roller in the tank 502. In addition to driving the refresh roller 506a, which is disposed to be pressed by the 504, the developing belt 510 serving as a developer support, and the developing belt 510, The drive rollers 51 a, 51 b, and 51 c hold a part of the development belt 510 so as to contact the photoreceptor 10 and the application roller 504. Thereafter, a removal blade 514 for removing the liquid developer 508 attached to the development belt 510 is provided.

As shown in FIG. 21, the supply roller 504 includes a cylindrical body 504a and a sponge 504b covering the cylindrical body 504a. The supply roller 504 rotates in a direction opposite to the rotation direction of the developing belt 510, so that the liquid developer 508 stored in the tank 502 is sponged with the liquid. The liquid developer 508 absorbed in the sponge 504b is released while being absorbed in the 504b, and is applied to the developing belt 510. The thickness t of the sponge 504 b is 1 to

4 mm is preferred. If the thickness t of the sponge 504b is less than 1 mm, it becomes difficult to manufacture the supply roller 504. On the other hand, the sponge 504

The liquid developer 508 that is not released to the outside remains in the 504 b, which may cause the sponge 504 to be clogged. The liquid amount of the liquid developer 508 held by the sponge 504 b depends on the thickness t, the porosity, and the porosity of the sponge 504 b. It is determined by the pore diameter. Therefore, sponge 5 0

The thickness t, porosity, and pore diameter of 4b should be determined in consideration of the amount of liquid developer 508 applied to the developing belt 510. According to experiments performed by the present inventors, when the thickness t of the sponge 504 b is 1 mm, the porosity is 80%, and the pore diameter is 30 m, a small amount of a high-concentration highly viscous liquid is obtained. The developer 508 could be applied evenly and thinly on the developing belt 510. In general, the pore diameter of the sponge 50.4b is very small, so that it is possible to prevent the liquid developer 508 from waving when the liquid developer 508 is discharged. You.

The refresh roller 506a rotates in the direction opposite to the rotation direction of the supply roller 504, and thus remains in the sponge 504b of the supply roller 504. Liquid developer

Spit all 5 08. As a result, the liquid developer 508 in the sponge 504b is constantly circulated.

The developing belt 5 10 1 is rotated by the driving rollers 5 12 a, 5 12 b, 5 12 c in a direction opposite to the rotation direction of the photoreceptor 10. The liquid developer 508 applied to the surface of the photoreceptor 10 by the supply roller 504 is conveyed. The material and operation of the developing belt 510 are not different from those in the second embodiment.

Next, the operation of the electrostatic latent image liquid developing apparatus according to the third embodiment of the present invention will be described.

In the liquid developing device for an electrostatic latent image according to the third embodiment, an electrostatic latent image is formed on the surface of the photoconductor 10 as in the first embodiment. After applying the pre-wet liquid, the electrostatic latent image is visualized by the developing device 50. The liquid developer 508 stored in the tank 502 is absorbed by the supply roller 540 and then applied to the developing belt 510. By setting the thickness t, porosity and pore diameter of the sponge 504 b of the application roller 504 to predetermined values, a small amount of the liquid developer 508 can be used as the developing belt 510 , And a thin liquid developing agent layer is formed on the developing belt 510. The liquid developer 508 remaining in the sponge 504b of the supply roller 504 is discharged by the refresh roller 506a. As a result, the developing belt 510 is always coated with a new liquid developer 508.

Thereafter, the transfer and fixing of the toner image are performed according to the same steps as those of the liquid developing device of the first embodiment.

According to the third embodiment of the present invention, the high density and high density are achieved by the supply roller 540 coated with the sponge 504b having the predetermined thickness t, porosity and pore diameter. A small amount of liquid developer 508 is applied thinly and evenly to developing belt 510 by using a developing device that applies viscous liquid developer 508 to developing belt 510. Therefore, the developing belt 510 can supply a small amount of a high-concentration and high-viscosity liquid developer uniformly to the latent image surface of the photoconductor # 0. According to the third embodiment, the supply roller 504 is maintained. By using a developing device in which a refresher roller 506 that squeezes out the liquid developer 508 that is held by the supply roller 504 is used, the supply roller 5 The liquid developer 508 remaining in the sponge 504 b of the · 0 · 40 can be completely discharged every rotation. Therefore, it is possible to prevent the sponge from being clogged, and it is possible to always supply a new developer to the developing belt 5100. 3 Another embodiment of the embodiment will be described with reference to FIG. FIG. 22 is a schematic view of another embodiment of the developing device used for the electrostatic latent image liquid developing device according to the third embodiment. Incidentally, in the liquid developing device for an electrostatic latent image in this embodiment, those having the same functions as those in the third embodiment described above are denoted by the same reference numerals or corresponding reference numerals, and the details thereof are given. Detailed description is omitted.

The second embodiment of the third embodiment of the present invention is different from the first embodiment shown in FIG. 20 in that the electrostatic latent image liquid developing apparatus is different from that of the first embodiment shown in FIG. In other words, a developing device 52 is used in place of the developing device 50. More specifically, the difference between the developing device 52 of the second embodiment and the developing device 50 of the first embodiment is that the developing agent 50 0 in FIG. It has the function of a supply roller 504 for supplying the toner, and as shown in FIG. 22, is supplied by the supply roller 504 between the supply roller 504 and the developing belt 501. An application roller 522 for applying the liquid developer 508 to the development belt 5110 is provided. The developing device 54 configured as described above supplies the liquid developer 508 stored in the tank 502 to the application roller 522 by the supply roller 504. The application roller 522 applies the liquid developer 508 supplied by the supply roller 504 to the development belt 510. Since other operations of the electrostatic latent image liquid developing device according to the second embodiment are the same as those of the first embodiment, detailed description thereof will be omitted.

According to the second aspect, a developing device for applying the liquid developer 508 supplied by the supply roller 504 to the development belt 510 via the application roller 522 is used. As a result, a small amount of high-concentration and high-viscosity liquid developer can be applied evenly and uniformly to the current belt 510, resulting in a small amount of high-concentration and high-viscosity liquid developer. The agent can be supplied more uniformly to the latent image surface of the photoconductor 10. Other effects are the same as in the first embodiment.

Note that, in the second embodiment, the developing device in which one coating roller 522 is interposed between the supply roller 504 and the developing belt 510 has been described. The invention is not limited to this, and the developing device is provided between the supply roller 504 and the developing belt 5100 via one or more transport rollers. Is also good. By increasing the number of transport rollers, a high-concentration and high-viscosity liquid developer can be evenly and uniformly applied on the developer support. However, considering the miniaturization of the apparatus, there is an optimum number of rollers for forming the developer thin layer. The present embodiment is not limited to the above embodiments, and various modifications can be made within the scope of the invention. For example, in each of the above-described embodiments, the application roller used in the developing device is constituted by the cylindrical body 504a and the sponge 504b covering the cylindrical body 504a. Although the present embodiment has been described, the present embodiment is not limited to this, and the application roller is constituted by a cylindrical body and a sponge 504b covering the cylindrical body. You may. Also, the supply roller 504 has been described as being partially immersed in the liquid developer 508 stored in the tank 502, but the present invention is not limited to this. However, the present invention is not limited to this, and the coating roller may be disposed, for example, between the transport roller and the developing belt. In this case, a small amount of the liquid developer can be applied to the developing belt by adjusting the amount of the liquid developer conveyed by the conveying roller by the application roller.

Further, in each aspect of the third embodiment described above, the developing device using the developing belt 510 made of a flexible member for the developer support has been described. The present invention is not limited to this, and the developing device may use a developing roller formed of a conductive member made of a rigid or elastic material such as metal on a developer support. However, the liquid developer layer formed on the developing roller and the split liquid layer formed on the image support are brought into contact with each other while maintaining a two-layer state, and the two layers are split. Inside the liquid layer In order to separate the developing roller, the developing roller is disposed so as to form a small gap d between the developing roller and the photoconductor, or as shown in a developing device 54 ′ shown in FIG. 23. A developing roller 540 is formed by rotating a developing roller 540 by a driving roller 122a, 122b, 122c. Must be in contact with

Further, in each of the above-described embodiments, the developing device is one in which the liquid developer 508 attached to the developing belt 510 is removed and removed by the blade 514. However, the present invention is not limited to this, and the developing device may cause the liquid developer 508 attached to the developing belt 510 to contact the developing belt 510. Opening

—It may be removed by a la.

Next, a fourth embodiment of the present invention will be described with reference to FIGS.

FIG. 24 is a schematic configuration diagram showing a first embodiment of a liquid developing device for an electrostatic latent image according to a fourth embodiment of the present invention, and FIG. 25 is a diagram showing a second embodiment of the fourth embodiment. FIG. 26 is a schematic configuration diagram showing a third mode of the fourth embodiment. Here, the reference numerals in the figure are the same as those in the first embodiment for members having the same functions.

As shown in FIG. 1, an electrostatic latent image liquid developing apparatus 1 according to a fourth embodiment of the present invention includes a photoconductor 10 serving as an image support and a split liquid on the photoconductor 10. Preparing to be applied Device 20, charging device 30 for charging photoconductor 10, exposure device 40 for exposing an image on photoconductor 10, and toner on a portion of photoconductor 10 where an electrostatic latent image is formed A developing device 50 for visualizing the electrostatic latent image by supplying the toner, a transfer device 60 for transferring and fixing the toner on the photoreceptor 10 to a predetermined paper, and a predetermined device. Paper feeder 610 for transporting paper to transfer device 60, cleaning device 70 for removing toner remaining on photoconductor 10, and charge elimination for charged photoconductor 10 And a static eliminator 80.

The difference between the liquid developing device for electrostatic latent images of the fourth embodiment and the liquid developing device of the first embodiment is a developing device 50 and a transfer device 60, so that the description of the other portions is omitted. The developing device 50 and the transfer device 60 will be described in detail.

The developing device 50 according to the first embodiment of the fourth embodiment includes a developing belt 510 which is a developer support, a driving device for rotating the developing belt 510 and a part of the developing belt 510. Driving π — la 5 12 a, 5 12 b, 5 12 c and liquid developer 508 applied to developing belt 5 10, which keeps it in contact with photoreceptor 10 And a removal blade 514 for removing the liquid developer 508 attached to the development belt 510 after the development.

The supply device 51 has four developing cartridges 51 a, 51 b, 51 c, and 51 d as color liquid developer supply means provided on a rotating shaft 509. Things. Each developing power The tank is a tank that stores the liquid developer 508 and a tank that releases the liquid developer 508 stored in the tank 502. A transfer roller 52 that supplies the liquid developer 508 discharged by the supply roller 506 to the application roller 506 described later. 2 and an application roller 506 for applying the liquid developer 508 supplied by the transport roller 522 to the development belt 510. The tank 502 of the developing cartridge 51a is filled with the liquid developer 508a containing the yellow toner, and the tank 502 of the developing cartridge 51b is filled with the liquid developer 508a. Is a liquid developer 508b containing magenta toner, and a tank 502 of the developing cartridge 51c is a liquid developer 508c containing cyanone toner. However, a liquid developer 508 d containing black toner is stored in the tank 502 of the developing cartridge 51 d. The supply device 51 rotates the rotation shaft 509 to rotate and move the developing cartridge 51, whereby the coating roller 506 of one of the developing cartridges 51 is moved. 0 is brought into contact with the developing belt 5 10. As a result, a liquid developer 508 containing a toner of a desired color can be applied to the developing belt 510.

The conveying roller 522 rotates in the opposite direction to the rotating direction of the application roller 506, and is discharged by the supply roller 506 onto the surface 20 of the application roller 506. The liquid developer 508 is conveyed. The application roller 550 rotates in a direction opposite to the rotation direction of the developing belt 510. The liquid developer 508 supplied by the transport rollers 522 is applied to the surface of the developing belt 510. As described later, in the first embodiment, the liquid developer 5 is used for supplying the liquid developer 5 08 to the developing belt 5 10 by using the transport roller 5 22 and the coating roller 5 0 6 0. Since a toner with a high concentration of toner was used in Fig. 08, a large amount of developer was not required, so that the developer could be evenly applied to the surface of the developing belt 5 10. Is most effective when applied by a roller. One or a plurality of transport rollers for transporting the liquid developer 508 may be provided between the transport roller 522 and the application roller 506.

The developing belt 510 is rotated by the driving rollers 512a, 512b, 512c in a direction opposite to the rotation direction of the photoconductor 10, and The liquid developer 508 applied to the surface of the photoconductor 10 by the application roller 504 is conveyed. It is no different from the first embodiment that the imaging belt 5100 is required to have flexibility and conductivity.

The transfer device 60 of the fourth embodiment includes an intermediate transfer belt 602 as an intermediate transfer member, and drive rollers 604a, 604b, 600 for rotationally driving the intermediate transfer belt 602. 4 c, holding rollers 605 a, 605 b for holding a part of the intermediate transfer belt 602 in contact with the photoconductor 10, and an intermediate transfer belt 602 And a secondary transfer member arranged so as to be in contact with the intermediate transfer belt 602. And a next transfer roller 603.

The intermediate transfer belt 602 is rotated in the opposite direction to the rotation direction of the photoconductor 10 'by the drive rollers 604a, 604b, 604c. A flexible member such as a resin belt such as a seamless nickel belt or a polyimide belt is used for the intermediate transfer belt 602. This makes it possible to disperse the contact pressure when the toner image formed on the photoconductor 10 and the intermediate transfer belt 602 come into contact with each other. When a resin belt is used, it is necessary to add conductive fine particles or to perform conductive processing on the surface of the belt so as to have a desired electric resistance value.

On the intermediate transfer belt 602, a surface layer having good releasability such as Teflon or silicon is formed. This is to reduce the physical adhesion of the toner to the intermediate transfer belt 602 and facilitate the transfer of the toner to the paper.

The secondary transfer roller 603 rotates in a direction opposite to the rotation direction of the intermediate transfer belt 602, so that the paper conveyed by the paper feeder 610 is transferred to the intermediate transfer belt 603. It is fed between the transfer roller 62 and the secondary transfer roller 63. At this time, the secondary transfer roller 603 is pressed against the intermediate transfer belt 602 via the paper. A secondary transfer bias is applied to the secondary transfer roller 603, so that the toner image formed on the intermediate transfer member 602 can be transferred to paper. Then, in the fixing device, the toner image is formed on the paper by the heating roller 702 and the pressing roller 701. Is established. Although not shown, a stationary heater for heating the drive roller 604a may be provided inside the drive roller 604a. The fixing heater may be provided inside the driving roller and also inside the secondary transfer roller 603 so as to heat the secondary transfer roller 603.

Next, the operation of the electrostatic latent image liquid developing apparatus according to the fourth embodiment of the present invention will be described.

In the liquid developing device for an electrostatic latent image according to the fourth embodiment, as in the first embodiment, an electrostatic latent image is formed on the surface of the photoreceptor 10 and the pre-wet liquid is applied. Then, the electrostatic latent image is visualized by the developing device 50. The liquid developer 508 discharged from the tank 502 by the supply roller 506 and supplied to the conveyance roller 522 is conveyed to the application roller 506, Coated on developing belt 5 10. The liquid developer 508 conveyed to the developing belt 510 via the roller in this way is thinly and evenly applied to the developing belt 510 and thinned on the developing belt 510. Form a layer. The supply device 51 rotates the rotating shaft 509 to move the developing cartridge 51, so that the coating port of one of the developing cartridges 51 can be moved. (5) Contact the developing belt (510) with the developing belt (510). This makes it possible to apply the liquid developer 508 containing any of yellow, magenta, cyan, and black to the developing belt 510 thinly and uniformly. .

Next, as shown in FIG. 3D, the liquid developer layer formed on the developing belt 5 10 is formed on the surface of the photoreceptor 10 as shown in FIG. 3D. The charged toner is moved to the photoreceptor 10 by electrostatic force near the latent image to form a toner image.

Next, the toner image formed on the photoreceptor '10 by the transfer device 60 is primarily transferred to an intermediate transfer belt 602 which is an intermediate transfer member. The toner image formed on the photoreceptor 10 is replaced with a toner image formed on the photoreceptor 10 in place of the roller 602 to which a voltage is applied as shown in FIG. On the intermediate transfer belt 602, due to the electrostatic force generated between the intermediate transfer belt 602 and the intermediate transfer belt 602 charged with a charge having the opposite polarity to the toner by the Rona discharger 606. To the primary transfer. On the other hand, the photoreceptor 10 is cleaned by the cleaning device 70 to remove the liquid developer 508 remaining on the photoreceptor 10, and thereafter, is discharged by the discharging device 80. Then, the developing cartridge 51 is rotated and moved to switch the developing cartridge 51 that contacts the developing belt 51, and then the above-described steps from the charging to the static elimination are performed again. By repeating the cycle, the toner images of yellow, yellow, cyan and black are sequentially transferred onto the intermediate transfer velorette 602 in a superimposed manner. As a result, a toner image corresponding to the colorization is formed on the intermediate transfer belt 602.

Next, the toner image corresponding to the color formed on the intermediate transfer belt 602 by the transfer device 60 is secondarily transferred to paper as a recording medium and fixed at the same time. The toner image corresponding to the color formed on the intermediate transfer belt 602 is the intermediate transfer by the drive roller 604a provided with the fixing heater. By heating the belt 602, it is separated from the intermediate transfer belt 602 having a surface layer having good releasability, and is conveyed by the paper feeder 610 to the intermediate transfer belt 602. It moves on the paper fed between the secondary transfer roller 6 and the secondary transfer roller 603, and is thermally fused and fixed at the same time as the secondary transfer. Thus, a color image can be formed on paper.

Instead of heating the driving roller 604a, a certain roller may be configured to heat the secondary transfer roller 603 at the same time.

According to the fourth embodiment of the present invention, a plurality of developing cartridges 51 a to 51 supplying the liquid developer for color 508 a to 508 d to the developing belt 510 are provided. By rotating and switching d and sequentially developing one developer cartridge by contacting one developer cartridge with the development belt 5 10, only one developer support is required. The size of the device can be reduced.

Next, a second embodiment of the fourth embodiment will be described with reference to FIG. FIG. 25 is a schematic diagram of a liquid developing apparatus for electrostatic latent images according to the second embodiment. In the liquid developer for electrostatic latent images according to the second embodiment, those having the same functions as those of the first embodiment are denoted by the same reference numerals or corresponding reference numerals, so that detailed descriptions thereof are given. Description is omitted.

The difference between the electrostatic latent image liquid developing device 2 of the second embodiment of the fourth embodiment and that of the first embodiment is that as shown in FIG. 25, the developing cartridges 51 a to 5 1 d is rotated and switched, and one developing force and one trigger are sequentially changed to the developing belt 5 10. Instead of the developing device 50 having the supply device 51 to be brought into contact with the developing device 50, the developing force mono-triggers 53 3 a to 53 d are moved in parallel and switched so that one developing power mono-trigger is sequentially formed. That is, a developing device 52 provided with a supply device 53 to be brought into contact with the developing belt 510 is used.

The supply device 53 includes a translation device (not shown) and developing forces 53 a, 53 b, 53 c and 53 arranged in parallel by being held by the translation device. d and a cam 5 2 9. The parallel moving device translates the developing cartridges 53 a to 53 d in parallel and sequentially moves one developing cartridge to a contact position with the developing belt 5 10. By rotating the cam 529, the developing cartridge moved to the contact position with the current belt 510 by the parallel moving device is moved to the developing belt 510. Abut.

In the developing device 52 having the above-described configuration, the developing cartridges 53a to 53d are translated in parallel by the parallel moving device, and one developing cartridge is sequentially moved to the developing belt 510. Then, the developing cartridge is brought into contact with the developing belt 510 by the cam 529. This makes it possible to apply the liquid developer 508 containing toner of a desired color to the developing belt 510. The other operations of the electrostatic latent image liquid developing device according to the second embodiment are the same as those according to the first embodiment, and a detailed description thereof will be omitted.

According to the second aspect, a plurality of developing carts for supplying the liquid developer for color 508 a to 508 d to the developing belt 510 are provided. The developer is supported by moving the ridges 53a to 53d in parallel and switching them so that one developing cartridge is sequentially brought into contact with the developing belt 510 to form an image. Since only one body is needed, the size of the device can be reduced. Other effects are the same as those of the first embodiment.

Next, a third embodiment of the fourth embodiment will be described with reference to FIG. FIG. 26 is a schematic view of a liquid developing device for an electrostatic latent image according to a third embodiment of the present invention. In the liquid developer for electrostatic latent images according to the third embodiment, those having the same functions as those of the first embodiment are denoted by the same reference numerals or corresponding reference numerals. Description is omitted.

The difference between the electrostatic latent image liquid developing device 3 of the third embodiment and that of the first embodiment is that the developing cartridges 51 a to 51 d shown in FIG. 24 are rotated and moved. As shown in FIG. 26, instead of the developing device 50 having a supply device 51 for switching and sequentially bringing one current cartridge into contact with the developing belt 51, the developing device 50 is provided as shown in FIG. A developing device 54 equipped with a separating means for sequentially separating and connecting the belt 510 to the developing cartridges 55a to 55d is used.

The developing device 54 drives the developing belt 540 as a developer support, rotates the developing belt 540, and abuts a part of the developing belt 540 on the photosensitive member 10. The driving rollers 54, 2a, 54, 2b held in this way, and the separating rollers, 54, 4a, 54, 4b, 54, 4c, 54, 4d, which are separating means, After developing, liquid developer 5 adhering to developing belt 5 10 A removal blade 5 14 for removing 0 8 is provided. The separating roller 544a rotates the developing belt 540, and separates a part of the developing belt 540 from the coating roller 550 of the developing cartridge 55a. The separating roller 544 b rotates the developing belt 540, and also transfers a part of the developing belt 540 to the coating port of the developing cartridge 55 b to the roller 506. Move away. The separating roller 544 c rotates the developing belt 540 and a part of the developing belt 540 is transferred to the coating roller 550 of the developing cartridge 55c. Move away. The separating roller 544 d rotates the developing belt 540 and rotates and separates a part of the developing belt 540 from the coating roller 550 of the developing cartridge 55 d.

In the developing device 54 having the above configuration, a part of the developing belt 540 is sequentially applied to the developing cartridges 55a to 55d by the separating rollers 544a to 544d. Contact This makes it possible to apply the liquid developer 508 containing toner of a desired color to the developing belt 540. The other operations of the electrostatic latent image liquid developing device according to the third embodiment are the same as those of the first embodiment, and thus detailed description thereof will be omitted.

According to the liquid developing device of the third aspect, the current cartridges 55 a to 55 supplying the liquid developer for color 508 a to 508 d to the developing belt 510 are provided. By developing the image by separating and contacting d and the developing belt 540, only one developer support is required, so that the size of the apparatus can be reduced. Other effects are the same as those of the first embodiment. The present invention is not limited to the above embodiments, and various modifications can be made within the scope of the invention. For example, in each of the above-described embodiments, the developing device includes a developing cartridge for supplying a liquid developer containing yellow toner to the developing belt, and a liquid containing magenta toner. Includes a developer cartridge that supplies developer to the developer belt, a developer cartridge that supplies liquid developer containing cyanogen toner to the developer belt, and black toner Although a description has been given of a developing cartridge having a developing cartridge for supplying a liquid developer to the developing belt, the present invention is not limited to this. The developing cartridge may be provided with two or three developing cartridges for supplying a liquid developer containing a developer to the developing belt as required.

In each of the above embodiments, the liquid developer 508 discharged from the supply roller 506 is applied via the transport roller 522 as a development cartridge of the developing device. A description has been given of the case where the toner is applied to the developing belt after being supplied to the roller 560. However, the present invention is not limited to this, and the current image cartridge is developed using the roller. Any material can be used as long as it supplies the liquid developer 508 to the belt 510. Means for applying the liquid developer 508 to the transport roller 522 is not limited to the supply roller 506, but is applied to the transport roller 522 by, for example, a bellows pump. It may be something.

Further, in each of the above embodiments, the developing device is a developing device. Although the description has been given of the case where the liquid developer 508 adhered to the nozzle is removed by the removal blade 514, the present invention is not limited to this. The liquid developer 508 adhering to the belt 510 may be removed by a wiper roller provided in contact with the developing belt 510.

Further, in each of the above embodiments, the transfer device transfers the toner image formed on the photoreceptor 10 to the intermediate transfer member, and then transfers the toner image to the intermediate transfer member. Although the present invention has been described for the secondary transfer of a toner image onto a recording medium, the present invention is not limited to this, and can transfer a toner image formed on a photoreceptor to a recording medium. That's fine.

Further, the case where the primary transfer on the intermediate transfer body is performed by electrostatic force has been described, but transfer by adhesive force may be performed.

In each of the embodiments, as a preset device, a preset liquid supply member 202 is used to apply a preset liquid 22 to the surface of the photoreceptor 10. Although the method of applying 0 has been described, the present invention is not limited to this, and the printing apparatus applies a predetermined amount of the printing liquid to the surface of the photoconductor. Any material that can be applied uniformly can be used. For example, the coating liquid may be applied by discharging a pre-jet liquid from a plurality of nozzles arranged in the axial direction, or may be applied by a sponge roller or the like. Further, in the above embodiment, the image is exposed on the charged image support by the exposure device 40, and thereafter, the image is exposed on the image support by the preset device 20. Although the case where the coating solution 222 is applied has been described, the present invention is not limited to this, and the application of the plating solution 220 is performed prior to the developing step. I just need.

Further, in the above embodiment, the case where the organic photoreceptor is used as the image support has been described. However, the present invention is not limited to this, and the image support may be a color support. It is also possible to use various photoreceptors used in the image forming method or a material in which an insulator layer is formed on a conductor directly forming an electrostatic latent image such as ionography, or an electrostatic recording paper such as an electrostatic probe.

Further, the present invention is not limited to the above-described embodiment, and a high-viscosity developing solution may be used if a plunger liquid layer is formed and the liquid developer has a layer thickness of 5 to 40 m. The viscosity of the agent may be 1000 mPas. At present, a high-viscosity developer with a viscosity of 600 mPa · s or more would be difficult to agitate the carrier liquid and toner, and would not be cost-effective. If it can be obtained at a low price, it may be 600 mPas or more. Viscosity exceeding lOOOOOmPa's becomes impractical.

In the above-described embodiment, the developing device using the developing belt 510 made of a flexible member for the developer support has been described, but the present invention is not limited to this. Instead, the developing device uses metal on the developer support. A developing roller formed of a conductive member such as the above may be used. However, the liquid developer layer formed on the developing roller and the pre-jet liquid layer formed on the photoreceptor are brought into contact with each other while maintaining a two-layer state, and the two are separated. In order to separate inside the liquid layer, it is necessary to arrange the developing roller so as to form a small gap d between the developing roller and the photoconductor.

Industrial applicability

The present invention relates to a method for applying a pre-wet liquid on an image support in an electrostatic latent image liquid developing apparatus, and a method for forming a thin and uniform liquid developer film on a developer support to support an image. By transferring to an electrostatic latent image on the body and developing it, it is possible to use a high-viscosity liquid developer in which toner is dispersed at a high concentration. The liquid developing device of the present invention requires an extremely small amount of liquid developer as compared with the conventional liquid developing device, and the carrier liquid has high safety, so that it does not require a sealing structure and is extremely compact. Structure.

When a layer-forming blade is provided so that the leading end comes in contact with the developer support in the trail direction, the layer thickness of the high-viscosity liquid developer applied to the developer support is reduced. Since uniform control can be achieved, a small amount of liquid developer can be uniformly supplied to the latent image surface of the image support.

Further, in the case where the liquid developer is supplied to the developer support via at least two rollers, the developer film on the surface of the developer support is thin and uniform. And therefore the picture An extremely small amount of liquid developer required for the latent image surface of the support can be uniformly supplied. In the case of a roller having at least one adjusting roller in contact with any one of the rollers, a liquid reservoir of the liquid developer is formed, thereby making the supply amount of the developer more uniform. effective.

Furthermore, those using an application roller having a thin sponge layer can apply a very small amount of liquid developer evenly and thinly on the surface of the developer support. In addition, the one provided with the refresh roller prevents the sponge of the application roller from clogging, and can always supply a new developing solution to the developer support.

Further, according to the apparatus having a plurality of developer supply means, it is sufficient to provide one developer support in common, and it is possible to form a color image with a small liquid developing apparatus. is there.

Claims

The scope of the claims

1. An electrostatic latent image liquid developing apparatus for developing an electrostatic latent image formed on an image support by toner, which is a charged visualization particle,

A liquid developer having a viscosity of 100 to 100 OmPas in which toner is dispersed in a high concentration in a developer support and an insulating liquid is developed to a thickness of 5 to 40 m. Developing means for applying the liquid developer to the surface of the image support via the developer support;

A liquid developing device for an electrostatic latent image, comprising:

2. It is further provided with a plunging means for applying a plunging liquid, which is a dielectric liquid having releasability and chemically inactive, on the image support. The liquid developing device for an electrostatic latent image according to claim 1, wherein:

3. The electrostatic latent image according to claim 1, wherein the coating unit is a layer-forming blade provided so as to contact the developer support in a trail direction. Liquid imaging device.

4. The method according to claim 3, wherein the layer forming blade is provided such that a tip thereof protrudes from 10 to 100 / m from a contact position with the developer support. Liquid developing device for electrostatic latent image

5. The layer forming blade is formed of an elastic member that does not swell in the insulating liquid used for the high-viscosity liquid developer. The liquid developing device for an electrostatic latent image according to claim 3, wherein the liquid developing device is a liquid developing device.

6. The electrostatic latent image liquid developing device according to claim 1, wherein the coating unit includes at least two rollers.

7. The developing means has at least one adjusting roller for adjusting the liquid amount of the liquid developer adhered to the roller to one of the at least two rollers. 7. The liquid developing device for an electrostatic latent image according to claim 6, wherein:

8. The electrostatic latent image liquid developing device according to claim 1, wherein the application unit is an application roller whose surface is covered with a sponge.

9. The electrostatic latent image liquid developing device according to claim 8, wherein the application roller has a thickness of the sponge of 1 to 4 mm.

10. The developing means squeezes out the high-viscosity liquid developer held by the application roller, and causes the application roller to absorb the high-viscosity liquid developer. The liquid developing device for an electrostatic latent image according to claim 8, wherein the liquid is pressed against the application roller.

11. The coating means comprises a plurality of developer supply means for applying different liquid developers to the surface of the developer support, and the developer support has flexibility and conductivity. 3. The liquid developing device for an electrostatic latent image according to claim 1, wherein the liquid developing device is formed of a thin plate member.

12. The electrostatic latent device according to claim 11, wherein the plurality of developer supply units are rotated and switched so that one developer supply unit is sequentially brought into contact with the developer support. Liquid image development device.

13. The electrostatic latent device according to claim 11, wherein the plurality of developer supply units are moved in parallel and switched to sequentially contact one developer supply unit with the developer support. Liquid image development device.

14. The liquid developing device for an electrostatic latent image according to claim 11, further comprising: a separation / contact means for selectively separating / contacting the developer support and the plurality of developer supply means.

15. The liquid developer insulating viscosity of the liquid is 0 5 ~ 1 0 0 O m P a -. S, electrical resistance ¹ 0 1 ² Ω cm or more, surface tension is 2 1 dyn / cm or less, 3. The electrostatic latent image liquid developing device according to claim 1, wherein the boiling point is 100 ° C. or higher.

16. The liquid developer according to claim 1, wherein silicon oil is used as an insulating liquid.

6. A liquid developing device for an electrostatic latent image according to 5.

17. The liquid for an electrostatic latent image according to claim 1, wherein the liquid developer contains toner having an average particle diameter of 0.1 to 5 m at a concentration of 5 to 40%. Developing device.

18. The pre-wet solution has a viscosity of 0.5 to 5 mP a ■ s, electrical resistance 1 0 ^{1 2} Omega cm or more, according to claim 1 or 2 having a boiling point of 1 0 0 ~ 2 5 0 ° C, a surface tension of 2 1 dyn cm or less, that it is an an FEATURE: To 19. The electrostatic latent image liquid developing device according to claim 19, wherein the plunger liquid is mainly composed of silicone oil. Liquid developing device for latent images.