Image forming apparatus and image forming method

1. An image forming apparatus, comprising:

an ink ejection device which ejects a droplet of radiation-curable ink onto a recording medium;

a solvent separating device which separates a coloring material component from a solvent component in the droplet of the radiation-curable ink on the recording medium by using an electrophoresis effect;

a solvent removing device which removes the solvent component separated by the solvent separating device; and

a curing device which irradiates radiation onto the droplet of the radiation-curable ink after the solvent component is removed by the solvent removing device, in such a manner that the droplet of the radiation-curable ink is cured,

wherein the solvent separating device includes:

an electrically charging device which electrically charges the droplet of the radiation-curable ink on the recording medium;

a recording medium holding member on which the recording medium is held; and

an electric field application device which applies an electric field to the electrically charged droplet on the recording medium held on the recording medium holding member, the electric field application device having a DC power source which is electrically connected to the solvent removing device and the recording medium holding member and applies a DC voltage between the solvent removing device and the recording medium holding member.

2. The image forming apparatus as defined in claim 1 , wherein the solvent removing device comprises a porous member which absorbs the solvent component.

3. The image forming apparatus as defined in claim 1 , further comprising a solvent removal amount control device which controls an amount of the solvent component removed by the solvent removing device.

4. The image forming apparatus as defined in claim 3 , wherein the solvent removal amount control device controls a distance between the solvent removing device and the recording medium.

5. The image forming apparatus as defined in claim 3 , wherein the solvent removal amount control device controls a contact pressure between the solvent removing device and the recording medium.

6. The image forming apparatus as defined in claim 3 , wherein the solvent removal amount control device controls at least one of a contact length and a contact duration between the solvent removing device and the recording medium.

7. The image forming apparatus as defined in claim 1 , wherein the solvent separating device forms aggregate of the coloring material in the droplet of the radiation-curable ink on the recording medium, by means of a two-liquid reaction.

8. An image forming method, comprising the steps of:

ejecting a droplet of radiation-curable ink onto a recording medium;

separating a coloring material component from a solvent component in the droplet of the radiation-curable ink on the recording medium by using an electrophoresis effect;

removing the solvent component separated in the separating step by a solvent removing device; and

irradiating radiation onto the droplet of the radiation-curable ink after the removing step, in such a manner that the droplet of the radiation-curable ink is cured,

wherein the separating step includes the steps of:

electrically charging the droplet of the radiation-curable ink on the recording medium;

holding the recording medium on a recording medium holding member; and

applying an electric field to the electrically charged droplet on the recording medium held on the recording medium holding member, by applying a DC voltage between the solvent removing device and the recording medium holding member by a DC power source which is electrically connected to the solvent removing device and the recording medium holding member.

9. An image forming method, comprising the steps of:

ejecting a droplet of radiation-curable ink onto a recording medium;

separating a coloring material component and a solvent component in the droplet of the radiation-curable ink on the recording medium;

removing the solvent component separated in the separating step;

irradiating radiation onto the droplet of the radiation-curable ink after the removing step, in such a manner that the droplet of the radiation-curable ink is cured;

gathering the solvent component removed in the removing step; and

adding a coloring material component to the solvent component gathered in the gathering step for reusing for new ink.