JPH02212149A - Image forming method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image forming method using a liquid as a recording medium.

[Prior Art] Conventional image forming methods using liquid as a recording medium, such as inkjet recording, perform recording by ejecting small droplets of a liquid recording medium called ink and making them adhere to a recording member. The method for generating droplets on the recording medium and the control method for controlling the flying direction of the generated recording medium droplets include:
There are several ways e.g. USP-3946398
There is a method represented by (Kys er method),
In the er method, an electrical recording signal is applied to a piezoelectric vibrator attached to a recording head having an orifice for ejecting a recording medium, and this electric recording signal is converted into mechanical vibration of the piezoelectric vibrator. Recording is performed by ejecting liquid droplets from the recording medium from the orifice according to the vibrations of the recording medium and depositing them on the recording member.

Further, as an image forming method using a liquid in a recording medium, there is also a wet electrophotography method using a liquid developer.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, after a liquid recording medium adheres to a recording member such as a recording paper, the recording material is damaged as the solvent constituting the recording medium permeates into the recording member. Coloring materials such as pigments that are dispersed throughout the body also permeate into the recording member, resulting in a problem that the recorded image becomes blurred and resolution cannot be obtained or recording density cannot be achieved.

SUMMARY OF THE INVENTION The present invention is intended to solve these problems, and its purpose is to provide an image forming method that uses a liquid as a recording medium and that enables high resolution and high recording density. It is in.

[Means for Solving the Problems] The image forming method of the present invention uses an electrorheological fluid in which a coloring material is dispersed in an insulating solvent as the recording medium in an image forming method using a liquid as the recording medium, and the image forming method uses a liquid as the recording medium. The method is characterized in that after the recording body is attached to the recording member, an electric field is applied to the recording member to which the recording body is attached.

[Function] According to the above configuration of the present invention, an electrorheological fluid in which a coloring material is dispersed in an insulating solvent is used as a recording medium, and after the recording medium is attached to a recording member such as recording paper, the recording medium is attached. By applying an electric field to the recording member, the coloring material in the recording medium is arranged in a chain shape on the recording member, apparently turning into giant particles.
Penetration of the coloring material into the recording member is prevented, and bleeding of the recording and decrease in recording density are prevented. As a result, it is possible to form images with high resolution and high recording density.Electrorheological fluid is a general term for liquids whose viscosity increases with the application of an external electric field (Inazawa: Hydraulic Technology).

vol, 14. No. 9.19-23 (1975))
,? There are two types: a pure single system consisting of only 8 media and a particle dispersion system in which a dispersoid is added to the dispersion medium, but the particle dispersion system is more
The viscosity changes significantly with respect to electric field strength.

In the case of a particle dispersion system, the magnitude of viscosity change varies depending on not only the electric field strength but also the combination of materials and particle concentration. The dispersion medium that can be used in the present invention has high insulation properties (electrical resistance of 10
1aΩCm or more), petroleum-based aliphatic hydrocarbons with a low dielectric constant (dielectric constant 3 or less); For example, hydrocarbon solvents such as hexane, octane, cyclopentane, benzene, toluene, and quidylol; For example, carbon tetrachloride, trichloroethylene, Examples of colorants that can be used in the present invention include inorganic pigments such as titanium white, iron black, and carbon black; and organic pigments such as phthalocyanine. .

In a particle dispersion system of electrorheological fluids, if no electric field is applied, the particles are dispersed in the dispersion medium (Figure 2 (a)).
), by applying an electric field, the particles in the dispersion medium are arranged in a chain shape (FIG. 2(b)), and appear to be gigantic particles. By using a coloring material as particles constituting the electrorheological fluid, it is possible to impart an electrorheological effect to the recording medium. After forming a recorded image on a recording member such as paper using a recording medium with an electrorheological effect, by applying an electric field to the recording member, the colorant is made into giant particles on the recording member, and the dispersion in the recording medium is It is possible to prevent the coloring material from permeating into the recording member at the same time as the coloring material permeates into the recording member, and to keep the coloring material on the surface of the recording member. As a result, blurring of the recorded image and decrease in recording density are prevented, and an image with high resolution and high recording density can be formed.

Hereinafter, the present invention will be explained in detail with reference to Examples.

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

As a recording medium that is an electrorheological fluid, 0.02
Dispersed μm carbon black (viscosity coefficient 2
cP, 20°C> was prepared. The recording medium was supplied into the inkjet printer head 6 having an orifice with a diameter of 100 μm using an appropriate pressurizing means such as a pump at a pressure such that it could not be ejected from the orifice by itself.

When a piezo vibrator attached to the top of the inkjet printer head 6 was mechanically vibrated at 3 kHz, the recording material was ejected from the orifice in the form of droplets and adhered to the recording paper 3. The recording paper 3 to which the recording material was attached was transported by a transport roller 4, and the recording material was dried and fixed while passing under the electric field formed by the electrode 1. No bleeding was observed in the recorded image on the recording paper 3 after drying and fixing, and the recorded density was 1.5 in terms of OD value.

Furthermore, no carbon black precipitation or orifice clogging occurred.

Note that the composition of the recording body, the applied electric field, the configuration of the inkjet printer head 6, the diameter of the orifice, etc. are not limited to those described above, and the ejection of the recording body 7 is also limited to that using a piezo vibrator. It's not a thing. Furthermore, the configuration of the electrodes 1 for applying an electric field is not limited to the configuration in which the recording paper is sandwiched from above and below as shown in FIG. 1, but may also be configured such that it is sandwiched from the left and right sides.

After attaching the comparative recording material to the recording paper, image formation was performed in the same manner as in Example 1, except that no electric field was applied using the electrodes. Ori,
The recording density was also only 0.9 in terms of OD value.

Embodiment 2 FIG. 3 is a schematic diagram of an image forming apparatus according to another embodiment of the image forming method of the present invention.

As a recording medium that is an electrorheological fluid, 0.02
Dispersed μm carbon black (viscosity coefficient 2
cP, 20°C). The recording medium was supplied into the inkjet printer head 6 having an orifice with a diameter of 100 μm using an appropriate pressurizing means such as a pump at a pressure such that it could not be ejected from the orifice by itself.

When a piezo vibrator attached to the top of the inkjet printer head 6 was mechanically vibrated at 3 kHz, the recording material was ejected from the orifice in the form of droplets and adhered to the recording paper 3. The recording paper 3 to which the recording material was attached was transported by a transport roller 4, and the recording material was dried and fixed while passing under an electric field formed by a corona charger 7. No bleeding was observed on the recorded image on the recording paper after drying and fixing.
A recording density of 1°5 was also obtained in terms of OD value.

Embodiment 3 FIG. 4 is a schematic diagram of an image forming apparatus according to another embodiment of the image forming method of the present invention.

As a liquid developer that is an electrorheological fluid, 0,
A material in which 5 μm carbon black was dispersed was prepared.

The latent image carrier 8 has a photoconductive layer 9 deposited on a conductive support 10, and the photosensitive layer 9 is charged to a predetermined potential using a charger 7a. Later, the light emitted from a light source such as a laser is scanned using a rotating polygon mirror (not shown), and an image is formed on the photosensitive layer 9 by an imaging optical system to obtain a potential contrast, and an image is immobilized on the latent image carrier 8. An electrolatent image was formed. On the other hand, the developing device 11 is used to charge a liquid developer, which is an image forming body, and to supply the liquid developer. A voltage is applied by the developing bias applying means to the latent image carrier 8.
A developing electric field is generated according to the potential contrast of the electrostatic latent image of the latent image carrier 8, and a charged liquid developer is electrophoresed toward the electrostatic latent image of the latent image carrier 8 to obtain the toner adhesion amount according to the potential contrast. The latent image was made visible, and the liquid developer deposited on the latent image carrier 8 was electrostatically transferred onto the recording paper 3 by a corona charger 7b (transfer device).

When drying and fixing the liquid developer onto the recording paper 3 by means such as heating, an electric field was applied through the electrode 1. No bleeding was observed in the recorded image on the recording paper 3 after drying and fixing, and the recorded density was 1.5 in terms of OD value.

Further, in FIG. 4, the arrows indicate the rotation direction of each member, but this does not limit the present invention, and the above-mentioned numerical values also do not limit the present invention. The method of constructing the photosensitive layer 9 and the like are not limited to those shown in this figure.

[! f! As described above, according to the present invention, in an image forming method using a liquid as a recording medium, an electrorheological fluid in which a coloring material is dispersed in an insulating solvent is used as the recording medium, and the recording medium is By applying an electric field to the recording paper to which the recording material is attached after attaching the recording material to the recording paper, it is possible to perform high-density recording and high-density recording.

[Brief explanation of the drawing]

FIG. 1 shows a principle diagram of an embodiment of the image forming method of the present invention.
FIG. 3 is a schematic diagram of an image forming apparatus according to another embodiment of the image forming method of the present invention, and FIG. 4 is a schematic diagram of an image forming apparatus of another embodiment according to the image forming method of the present invention. Electrode Power source Recording paper conveyance roller Platen roller Inkjet spatula Corona charger Latent image carrier Photosensitive layer Conductive support Developing device Heat roll Backup roll (a) Figure 2 (b) Figure 2 Figure 3

Claims (1)

[Claims] (1) In an image forming method using a liquid as a recording medium, an electrorheological fluid in which a coloring material is dispersed in an insulating solvent is used as the recording medium, and after the recording medium is attached to a recording member, the recording medium is An image forming method characterized by applying an electric field to a recording member to which is attached.