JPH11133755A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably obtain an excellent image without fog, even if a releasing material is infiltrated into ink in an ink developing device, in the case the ink comes into contact with the surface of an image carrier coated with the releasing material, so as to form an ink image corresponding to an electrostatic latent image on the surface of the image carrier. SOLUTION: This image forming device is provided with a latent image forming device 20 for forming the electrostatic latent image on the surface of the image carrier 10, a releasing material coating device 30 for coating the surface of the image carrier with the nonconductive releasing material 31 and the ink developing device 40 for bringing the ink 41 into contact with the surface of the image carrier on which the electrostatic latent image is formed and which is coated with the releasing material, to form the ink image corresponding to the electrostatic latent image. Further, the image forming device is provided with an ink supplying device 51 for supplying different viscosity ink into the ink developing device, when the releasing material is infiltrated into the ink in the ink developing device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for forming an electrostatic latent image on the surface of an image carrier and applying a non-conductive release material to the surface of the image carrier. An image forming apparatus configured to form an ink image corresponding to an electrostatic latent image on the surface of the image carrier by bringing the ink in the ink developing device into contact with the surface of the image carrier formed and coated with the release material. In connection with this, even when the release material is mixed into the ink in the ink developing device, the ink is suppressed from adhering to the portion where the electrostatic latent image is not formed, so that a good image without fogging can be obtained. It is characterized by the following points.

[0002]

2. Description of the Related Art Conventionally, as typified by an electrophotographic copying machine, an electrostatic latent image is formed on the surface of an image carrier, and after developing the electrostatic latent image, the electrostatic latent image is formed on a recording medium such as paper. 2. Description of the Related Art An image forming apparatus that transfers an image onto a recording medium and forms an image on a recording medium is used.

As one of such electrophotographic image forming apparatuses, colored resin particles (toner particles) are used to develop an electrostatic latent image as disclosed in Japanese Patent Application Laid-Open No. 7-271107. One using a liquid developer dispersed in a carrier liquid is known.

Here, the liquid developer used in the electrophotographic apparatus is generally one in which charged toner particles are dispersed in an insulating carrier liquid, and the toner particles become liquid developer as an image is formed. When this liquid developer is used, it is necessary to control the concentration of the toner particles in the carrier liquid, and the management is troublesome, and most of the carrier liquid is used. Since the liquid developer is used repeatedly, there is a problem that the liquid developer is easily deteriorated.

Further, in an electrophotographic apparatus using such a liquid developer, when an image is formed on a recording medium such as copy paper, a fixing device for fixing a toner image transferred onto the recording medium or the like is used. Is required, and there is a problem that the apparatus becomes complicated and large.

[0006] Conventionally, Japanese Patent Publication No. 52-45
No. 494, etc., an electrostatic latent image is formed on the surface of an image carrier, and a non-conductive release material is applied to the surface of the image carrier. The ink held by the ink carrier in the ink developing device is brought into contact with the surface of the image carrier formed and coated with the non-conductive release material, and the ink is formed on the surface of the image carrier. 2. Description of the Related Art An image forming apparatus has been proposed in which an ink image corresponding to an electrostatic latent image is formed on a surface of an image carrier by adhering to an electrostatic latent image portion.

However, the ink held on the ink carrier is brought into contact with the surface of the image carrier on which the release material has been applied as described above, and the portion of the electrostatic latent image formed on the surface of the image carrier is exposed to the ink. When an image is formed, a part of the release material applied to the surface of the image carrier is held by the ink carrier and guided to the ink developing device, and the release material is contained in the ink in the ink developing device. And the viscosity of the ink in the ink developing device gradually changes, which causes ink to adhere to portions where no electrostatic latent image is formed, causing fogging of the formed image. was there.

[0008]

SUMMARY OF THE INVENTION According to the present invention, an ink in an ink developing device is brought into contact with the surface of an image carrier on which an electrostatic latent image is formed and a release material is applied, and the surface of the image carrier is brought into contact with the surface. It is an object of the present invention to solve the above-described problems in an image forming apparatus that forms an ink image corresponding to an electrostatic latent image.

That is, according to the present invention, in the image forming apparatus as described above, the ink in the ink developing device is brought into contact with the surface of the image carrier to which the release material has been applied as described above, and thereby the surface of the image carrier is formed. When an ink image corresponding to an electrostatic latent image is formed, even if a release material is mixed into the ink in the ink developing device, the viscosity of the ink changes and an image bearing member on which an electrostatic latent image is not formed is formed. It is an object of the present invention to prevent ink from adhering to the surface of a body, suppress occurrence of fogging in an image to be formed, and stably obtain a good image.

[0010]

According to a first aspect of the present invention, there is provided an image forming apparatus for forming an electrostatic latent image on a surface of an image bearing member. A release material application device for applying a non-conductive release material to the surface of the image carrier, and an electrostatic latent image formed on the surface of the image carrier to which the release material is applied and the electrostatic contact made by contacting ink. An image forming apparatus including an ink developing device for forming an ink image corresponding to a latent image, wherein when a release material is mixed into the ink in the ink developing device, ink having a different viscosity is supplied to the ink developing device. An ink supply device for supplying ink is provided.

In the image forming apparatus according to the first aspect of the present invention, when the release material applied to the surface of the image carrier is mixed into the ink in the ink developing device, the ink having a different viscosity from the ink supply device. The ink is supplied to the ink developing device so that the viscosity of the ink in the ink developing device is prevented from changing due to the mixing of the release material.

Thus, even when the release material is mixed into the ink in the ink developing device, the viscosity of the ink in the ink developing device is maintained at an appropriate viscosity,
Ink is prevented from adhering to a portion where an electrostatic latent image is not formed as in the related art, and a good image is stably obtained without fogging of the formed image. .

Further, when the release material is mixed as described above, the ink supply device supplies ink having different viscosities to the ink developing device to adjust the viscosity of the ink in the ink developing device. The amount of the release material mixed into the ink is detected based on the image data of the electrostatic latent image formed on the surface of the image carrier, and the ink having different viscosities by the ink replenishing device is detected. It is preferable to provide control means for controlling the replenishment.

Here, the principle of detecting the amount of the release material mixed in the ink based on the image data of the electrostatic latent image formed on the surface of the image carrier will be described. The amount of the release material changes depending on the ratio between the portion of the electrostatic latent image formed on the surface of the image carrier and the portion where the electrostatic latent image is not formed. When the amount of the release material mixed in the ink decreases and there are many portions where the electrostatic latent image is not formed, the amount of the release material mixed in the ink increases.

That is, when the development is performed by bringing the ink into contact with the surface of the image carrier coated with the release material as described above, the ink pushes away the release material at the portion where the electrostatic latent image is formed. In a portion where the electrostatic latent image is not formed, a release material is interposed between the surface of the image carrier and the ink while the electrostatic latent image is formed on the surface of the image carrier. When the ink in contact with the surface of the body separates from the image carrier, in the portion where the electrostatic latent image is formed,
The portion of the ink adhered to the surface of the image carrier is cut and the ink remains on the image carrier, while the portion where the electrostatic latent image is not formed is separated from the surface of the image carrier and the ink. The portion of the mold material is cut, and a part of the release material cut in this way is mixed into the ink in the ink developing device.

Therefore, the amount of the release material mixed into the ink can be accurately detected based on the image data of the electrostatic latent image formed on the surface of the image carrier. When the amount of replenishing ink having different viscosity from the ink replenishing device to the ink developing device is controlled by the control means based on the amount of the releasing material mixed into the ink developing device, Even when the ink is mixed in the ink, the viscosity of the ink in the ink developing device is maintained at an appropriate viscosity, and a good image can be stably obtained without causing fogging of the formed image.

Here, in the image forming apparatus according to the present invention, as the above-mentioned image carrier, one having a dielectric layer formed on the surface of a conductive member or a photosensitive layer formed on the surface of a conductive member is used. An electrophotographic photoreceptor can be used.

In this image carrier, the material constituting the conductive member is, for example, a metal such as aluminum, iron, copper, nickel, SUS, gold, silver, chromium, platinum, tin, or titanium. In addition to these alloy materials, a material in which these conductive materials are dispersed in a resin can be used. When the conductive material is dispersed in the resin as described above, the resin may be polyethylene, polypropylene, polyvinyl alcohol, polyvinyl acetate, ethylene-vinyl acetate copolymer, polymethyl methacrylate, polycarbonate, polystyrene, acrylonitrile. -Methyl acrylate copolymer, acrylonitrile-butadiene-styrene copolymer, poly (ethylene terephthalate), polyurethane elastomer, polyamide,
Polyimide or the like can be used.

The material constituting the dielectric layer provided on the conductive member is, for example, polyester,
Polypropylene, polyvinyl alcohol, polyvinyl acetate, ethylene-vinyl acetate copolymer, polymethyl methacrylate, polycarbonate, polystyrene, acrylonitrile-methyl acrylate copolymer, acrylonitrile-butadiene-styrene copolymer, poly (ethylene terephthalate), polyurethane Elastomer, viscose rayon, cellulose nitrate, cellulose acetate, cellulose triacetate, cellulose propionate, cellulose acetate butyrate, ethyl cellulose regenerated cellulose, polyamide (nylon 6, nylon 66, nylon 11, nylon 12, nylon 46, etc.), polyimide, polysulfone , Polyether sulfone, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinylidene chloride, vinylidene chloride-vinyl chloride copolymer, Alkenyl nitrile rubber alloy, polytetrafluoroethylene, polychlorofluoroethylene, polyvinyl fluoride, and resins such as polyvinylidene fluoride, Al
₂ O _3, SiO _2, a ceramic such as TiO ₂ may be an inorganic material, it is also possible to use a combination of such a dielectric material of two or more.

As the photosensitive layer provided on the above-mentioned conductive member, a photosensitive layer generally used in an electrophotographic photosensitive member can be used.

When a latent image forming apparatus for forming an electrostatic latent image on the surface of an image carrier uses an image carrier in which a dielectric layer is formed on the surface of a conductive member, this image carrier is used. A discharge device or an ion-flow type electrostatic head for forming an electrostatic latent image by giving an electric charge according to an image to the dielectric layer on the surface of the carrier is used, and a photosensitive layer is formed on the surface of the conductive member. When an image carrier made of the formed photoconductor is used, various types of exposure such as a charging device for charging the surface of the image carrier and a laser device for exposing the surface of the image carrier thus charged are used. Use in combination with the device.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an image forming apparatus according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings.

In the image forming apparatus according to this embodiment, as shown in FIG. 1, an image carrier 10 having a photosensitive layer 12 formed on the surface of a conductive member 11 is used.
The image carrier 10 is rotated, and an electrostatic latent image is formed on the surface of the image carrier 10 by the latent image forming device 20.

In this embodiment, as the latent image forming device 20, a charging device 21 for uniformly charging the surface of the image carrier 10 and an image carrier 1 charged in this way are used.
The surface of the image carrier 10 is uniformly charged by the charging device 21 using the exposure device 22 that performs exposure according to the image data given from the controller 50 to the surface of the image carrier 10. Exposure device 22 for the surface of
The exposure is performed in accordance with the above image data to form an electrostatic latent image on the surface of the image carrier 10.

Then, a non-conductive release material 31 is applied from the release material application device 30 to the surface of the image carrier 10 on which the electrostatic latent image is formed.

Here, when the non-conductive release material 31 is applied to the surface of the image carrier 10 by the release material application device 30, in this embodiment, silicone oil or the like is used as the release material 31, and this release material is used. Form material 31 is stored in container 32
The release material 31 stored in the storage container 32 is held on the outer peripheral surface of the application roller 33, and the amount of the release material 31 held in this manner is regulated by a blade 34 to a predetermined thickness. The released release material 31 is applied to the application roller 3
The coating material 33 guides the release material 31 to the surface of the image carrier 10 so as to have an appropriate thickness.

Then, the ink 41 is supplied from the ink developing device 40 to the image carrier 10 coated with the release material 31 in this manner, and the portion of the electrostatic latent image formed on the surface of the image carrier 10 is To form an ink image corresponding to the electrostatic latent image on the surface of the image carrier 10.

Here, when an ink image is formed on the surface of the image carrier 10 by the ink developing device 40, the ink 4 whose viscosity decreases as the temperature increases.
1, the ink 41 is stored in the apparatus main body 42, the ink 41 is held on the surface of a rotating drum-shaped ink carrier 43, and the ink held on the surface of the ink carrier 43 is used. The amount of 41 is regulated by the regulating member 44 so that the ink 41 held on the surface of the ink carrier 43 has a predetermined layer thickness.

Then, the ink 41 held in such a manner as to have a predetermined layer thickness on the ink carrier 43 is brought into contact with the surface of the image carrier 10 to form the ink on the surface of the image carrier 10. An ink image corresponding to the electrostatic latent image is formed.

Here, in the image forming apparatus of this embodiment, the ink 41
The ink supply device 51 for supplying the ink 41 has a higher viscosity than the ink 41 in the ink developing device 40.
A first ink replenishing device 51a for replenishing the ink 41, and a second ink replenishing device 51b for replenishing the ink 41 having a viscosity equal to or less than the ink 41 in the ink developing device 40. The controller 50 that supplies image data to the device 22 supplies image data of the electrostatic latent image formed on the surface of the image carrier 10 to the control device 52, and the control device 52 mixes the image data into the ink 41 in the ink developing device 40. The controller 52 detects the amount of the mold material 31 and, based on the detected amount of the release material 31, controls each of the ink supply devices 5.
The amount of each ink 41 supplied from 1a and 51b is controlled.

After the ink image is formed on the surface of the image carrier 10 as described above, the ink image formed on the surface of the image carrier 10 by the transfer roller 60 as the transfer device 60 is transferred onto the recording medium 1. To be transcribed.

After the ink image is transferred to the recording medium 1 as described above, the ink 41 remaining on the surface of the image carrier 10 after the transfer is removed by the cleaning device 70 using the cleaning blade 71. After being removed from the surface of the image carrier 10, the charge remaining on the surface of the image carrier 10 is eliminated by the static eliminator 80, and a new electrostatic latent image is again formed on the surface of the image carrier 10 by the latent image forming device 20. Then, the above operation is repeated.

Here, in the image forming apparatus of this embodiment, when forming an image by repeating the above-described operations, based on the image data of the electrostatic latent image given from the controller 50 as described above, The control device 52 controls the ink 4 in the ink developing device 40.
1 and detects the amount of the release material 31 mixed in the ink replenishing device 51 based on the detected amount.
The amount of each ink 41 supplied from a and 51b is controlled and adjusted so that the ink 41 in the ink developing device 40 has an appropriate viscosity. For example, when the amount of the release material 31 mixed in the ink 41 increases and the viscosity of the ink 41 in the ink developing device 40 decreases, the first ink replenishing device 51a sends a high The ink 41 having the viscosity is supplied so that the viscosity of the ink 41 in the ink developing device 40 is increased, and the ink 41 is maintained at an appropriate viscosity even when the release material 31 is mixed.

When the viscosity of the ink 41 in the ink developing device 40 is appropriately maintained, the time for the ink 41 to reach the portion of the electrostatic latent image formed on the surface of the image carrier 10 becomes constant. As a result, the formed image is not fogged, and a good image can be stably obtained.

In the image forming apparatus shown in the above embodiment, the image carrier 10 having the photosensitive layer 12 formed on the surface of the conductive member 11 is used. However, as shown in FIG. As the image carrier 10, a member in which a dielectric layer 13 is formed on the surface of a conductive member 11 can be used.

In forming an electrostatic latent image by the latent image forming apparatus 20 on the surface of the image carrier 10 in which the dielectric layer 13 is formed on the surface of the conductive member 11 as shown in FIG. As described above, a latent image forming apparatus 20 such as an ion flow type electrostatic head is used, and the surface of the image carrier 10 is selectively charged by the latent image forming apparatus 20 to form an electrostatic latent image. After that, an image is formed in the same manner as the image forming apparatus in the above embodiment.

In such an image forming apparatus as well, the control unit 52 controls the separation into the ink 41 in the ink developing device 40 based on the image data of the electrostatic latent image supplied from the controller 50 as described above. The amount of the mold material 31 is detected, and based on the detected amount, the controller 52 controls the amount of each ink 41 to be supplied from each of the ink supply devices 51a and 51b so that the ink 41 in the ink developing device 40 has an appropriate viscosity. When the adjustment is made, the image to be formed is not fogged as in the case of the image forming apparatus in the above embodiment, and a good image can be obtained stably.

Further, as shown in FIG. 3, a belt-shaped image carrier 1 having a dielectric layer formed on the surface of a conductive member is provided.
The belt-shaped image carrier 10 is moved along with the rotation of the roller 14, and the surface of the belt-shaped image carrier 10 is moved by the ion-flow electrostatic The belt-shaped image carrier 1 is selectively charged by a latent image forming apparatus 20 using a head or the like.
It is also possible to form an electrostatic latent image on the surface of No. 0 and thereafter form an image in the same manner as in the image forming apparatus in the above embodiment.

In such an image forming apparatus as well, the control unit 52 controls the separation of the ink mixed in the ink 41 in the ink developing device 40 based on the image data of the electrostatic latent image provided from the controller 50 as described above. The amount of the mold material 31 is detected, and based on the detected amount, the controller 52 controls the amount of each ink 41 to be supplied from each of the ink supply devices 51a and 51b so that the ink 41 in the ink developing device 40 has an appropriate viscosity. When the adjustment is made, the image to be formed is not fogged as in the case of the image forming apparatus in the above embodiment, and a good image can be obtained stably.

[0040]

As described above in detail, in the image forming apparatus according to the present invention, the ink in the ink developing device is brought into contact with the surface of the image carrier on which the electrostatic latent image is formed and the release material is applied. In order to form an ink image corresponding to the electrostatic latent image, the ink developing device is provided with an ink replenishing device for replenishing inks having different viscosities, and a release material applied to the surface of the image carrier is used in the ink developing device. When the ink is mixed into the ink, the ink having a different viscosity is supplied from the ink supply device to the ink developing device to adjust the viscosity of the ink in the ink developing device.

Therefore, in the image forming apparatus according to the present invention, even when the release material applied to the surface of the image carrier is mixed into the ink in the ink developing device, the viscosity of the ink in the ink developing device changes. Is suppressed, the viscosity of the ink in the ink developing device is maintained at an appropriate viscosity, and the ink is suppressed from adhering to the portion where the electrostatic latent image is not formed,
A good image without fogging can be obtained stably.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory diagram of an image forming apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic illustration of an image forming apparatus according to another embodiment using an image carrier having a dielectric layer formed on the surface of a conductive member.

FIG. 3 is a schematic explanatory view of an image forming apparatus according to another embodiment using a belt-shaped image carrier in which a dielectric layer is formed on a surface of a conductive member.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 image carrier 20 latent image forming device 30 release material applying device 31 release material 40 ink developing device 41 ink 50 controller 51 ink replenishing device 51a first ink replenishing device 51b second ink replenishing device 52 control device

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Satoshi Izushi 2-3-13 Azuchi-cho, Chuo-ku, Osaka-shi Inside Osaka International Building Minolta Co., Ltd. (72) Inventor Takashi Kondo 2-3-3 Azuchi-cho, Chuo-ku, Osaka-shi No. 13 Osaka International Building Minolta Co., Ltd.

Claims (2)

[Claims] A latent image forming apparatus for forming an electrostatic latent image on the surface of the image carrier; a release material applying apparatus for applying a non-conductive release material on the surface of the image carrier; An ink developing device for forming an ink image corresponding to an electrostatic latent image by bringing ink into contact with the surface of the image carrier formed and coated with a release material; An image forming apparatus, comprising: an ink supply device that supplies ink having different viscosity to the ink developing device when a release material is mixed in the ink of (1). 2. The image forming apparatus according to claim 1, wherein an amount of the release material mixed into the ink is detected based on image data of an electrostatic latent image formed on a surface of the image carrier. An image forming apparatus comprising a control unit for controlling replenishment of inks having different viscosities by an ink replenishing device.