Liquid-development electrophotographic apparatus

A liquid-development electrophotographic apparatus, comprising:

• a development section using a nonvolatile, high-viscosity, high-concentration liquid toner as a liquid developer, the development section being in contact with an image bearer body, on which an electrostatic latent image is formed, so as to supply the liquid developer onto the image bearer body, and causing toner particles contained in the liquid developer to adhere to the image bearer body according to an electric field established between the development section and the image bearer body to thereby form a toner image;
• an intermediate transfer body to which the toner image is transferred from the image bearer body according to an electric field established between the same and the image bearer body;
• and
• a transfer-and-fixation section including a heater for melting the toner image transferred onto the intermediate transfer body through application of heat at a contact portion between the intermediate transfer body and a printing medium to thereby melt-transfer the toner image onto the printing medium,
• wherein a material having low surface energy (e.g., dimethyl silicone rubber) is used as a surface material, serving as an image formation surface, of the intermediate transfer body, and an electric resistance of the surface material is set to a semiconductive range of 1E4-1E12 Ω, and
• wherein in printing on a sheet requiring transparency, such as an OHP sheet, melt transfer is performed without prior removal of excessive oil, and after melt transfer is performed, excessive oil is removed from the sheet.

A liquid-development electrophotographic apparatus, comprising:

• a development section using a nonvolatile, high-viscosity, high-concentration liquid toner as a liquid developer, the development section being in contact with an image bearer body, on which an electrostatic latent image is formed, so as to supply the liquid developer onto the image bearer body, and causing toner particles contained in the liquid developer to adhere to the image bearer body according to an electric field established between the development section and the image bearer body to thereby form a toner image;
• an intermediate transfer body to which the toner image is transferred from the image bearer body according to an electric field established between the same and the image bearer body;
• and
• a transfer-and-fixation section including a pressure roller for melting the toner image transferred onto the intermediate transfer body through application of heat at a contact portion between the intermediate transfer body and a printing medium to thereby melt-transfer the toner image onto the printing medium,
• wherein a material whose resistance varies within a semiconductive range according to temperature is used as a surface material of the pressure roller, and temperature is controlled according to the printing medium to thereby apply an electric field at an optimum intensity.

A liquid-development electrophotographic apparatus, comprising:

• a development section using a nonvolatile, high-viscosity, high-concentration liquid toner as a liquid developer, the development section being in contact with an image bearer body, on which an electrostatic latent image is formed, so as to supply the liquid developer onto the image bearer body, and causing toner particles contained in the liquid developer to adhere to the image bearer body according to an electric field established between the development section and the image bearer body to thereby form a toner image;
• an intermediate transfer body which assumes the form of a belt and to which the toner image is transferred from the image bearer body according to an electric field established between the intermediate transfer body and the image bearer body, the intermediate transfer body being at least looped around and mounted on a heat roller;
• and
• a transfer-and-fixation section, including a pressure roller for melting the toner image transferred onto the intermediate transfer body through application of heat at a contact portion between the intermediate transfer body and a printing medium to thereby melt-transfer the toner image onto the printing medium,
• wherein the pressure roller is configured in such a manner as to contact the intermediate transfer body at a point where the intermediate transfer body leaves the heat roller, or in the vicinity of the point.

A liquid-development electrophotographic apparatus comprising a development section using a liquid toner as a developer, the development section being in contact with an image bearer body, on which an electrostatic latent image is formed, so as to supply the developer onto the image bearer body, and causing toner particles contained in the developer to adhere to the image bearer body according to an electric field established between the development section and the image bearer body to thereby form a toner image;

• an intermediate transfer section to which the toner image is transferred from the image bearer body;
• and a transfer-and-fixation section for melting the toner image transferred onto the intermediate transfer section through application of heat at a contact portion between the intermediate transfer section and a printing medium to thereby melt-transfer the toner image onto the printing medium,
• wherein the intermediate transfer section is equipped with an excessive-carrier-removing mechanism for removing excessive oil from a toner layer that forms an image on the intermediate transfer section;
• and
• wherein the excessive-carrier-removing mechanism comprises a semiconductive carrier-removing roller or belt which comes into contact with the toner layer heated to not lower than a melting temperature thereof or a temperature near the melting temperature and to which a bias voltage is applied in such a direction as to press toner particles against the intermediate transfer section retaining an image.

A liquid-development electrophotographic apparatus comprising a development section using a liquid toner as a liquid developer, the development section being in contact with an image bearer body, on which an electrostatic latent image is formed, so as to supply the liquid developer onto the image bearer body, and causing toner particles contained in the liquid developer to adhere to the image bearer body according to an electric field established between the development section and the image bearer body to thereby form a toner image;

• an intermediate transfer section to which the toner image is transferred from the image bearer body;
• and a transfer-and-fixation section for melting the toner image transferred onto the intermediate transfer section through application of heat at a contact portion between the intermediate transfer section and a printing medium to thereby melt-transfer the toner image onto the printing medium,
• wherein the intermediate transfer section comprises an intermediate transfer roller to which the toner image is transferred from the image bearer body according to an electric field established between the same and the image bearer body, and an intermediate transfer belt to which the toner image is transferred from the intermediate transfer roller, the toner image transferred onto the intermediate transfer belt being melt-transferred onto the printing medium.

A liquid-development electrophotographic apparatus comprising a development section using a liquid toner as a liquid developer, the development section being in contact with an image bearer body, on which an electrostatic latent image is formed, so as to supply the liquid developer onto the image bearer body, and causing toner particles contained in the liquid developer to adhere to the image bearer body according to an electric field established between the development section and the image bearer body to thereby form a toner image;

• an intermediate transfer section to which the toner image is transferred from the image bearer body;
• and a transfer-and-fixation section for melting the toner image transferred onto the intermediate transfer section through application of heat at a contact portion between the intermediate transfer section and a printing medium to thereby melt-transfer the toner image onto the printing medium.
• wherein the intermediate transfer section comprises a first intermediate transfer roller to which the toner image is transferred from the image bearer body according to an electric field established between the same and the image bearer body, and a second intermediate transfer roller to which the toner image is transferred from the first intermediate transfer roller, the toner image transferred onto the second intermediate transfer roller being melt-transferred onto the printing medium.

A liquid-development electrophotographic apparatus, comprising:

• a development section using a nonvolatile, high-viscosity, high-concentration liquid toner as a liquid developer, the development section being in contact with an image bearer body, on which an electrostatic latent image is formed, so as to supply the liquid developer onto the image bearer body, and causing toner particles contained in the liquid developer to adhere to the image bearer body according to an electric field established between the development section and the image bearer body to thereby form a toner image;
• an intermediate transfer body to which the toner image is transferred from the image bearer body according to an electric field established between the same and the image bearer body;
• and
• a transfer-and-fixation section including a heater for melting the toner image transferred onto the intermediate transfer body through application of heat at a contact portion between the intermediate transfer body and a printing medium to thereby melt-transfer the toner image onto the printing medium,
• wherein the development section is disposed at a lower portion of the apparatus to thereby prevent smudging of the printing medium and the intermediate transfer section even when a liquid toner spills.