Directly-heating roller of fixing a toner image and method of manufacturing the same

A heating roller, said heating roller comprising:

• a cylindrical roller body having an outer cylindrical surface;
• a heat-generating resistor layer formed around the outer cylindrical surface of the roller body, said heat-generating layer comprising ruthenium and lead;
• and
• two electrodes contacting the heat-generating resistor layer, for providing electricity to the heat-generating resistor layer.

A method of making a heating roller, comprising the steps of:

• applying a paste to a portion of the circumferential surface of a cylindrical roller body, said paste comprising:
• a first glass frit;
• a powdered ruthenium compound;
• a powdered silver compound;
• an organic binder;
• and
• an organic solvent;
• and
• heat-treating the paste to form a heat-generating resistor layer around the cylindrical roller body.

A method of making a heating roller, comprising the steps of:

• forming an electrically insulating layer around the circumferential surface of an electrically conductive cylindrical roller body;
• applying a first paste to a portion of the formed electrically insulating layer, said first paste comprising:
• a first glass frit;
• a powdered ruthenium compound;
• a powdered silver compound;
• an first organic binder;
• and
• a first organic solvent;
• and
• heat-treating the first paste to form a heat-generating resistor layer on the electrically insulating layer.

A process of making a heating roller, comprising:

• preparing a cylindrical roller having an exterior circumferential surface;
• applying to said exterior circumferential surface a paste comprised of:
• a glass frit,
• a powdered ruthenium compound,
• a powdered silver compound,
• an organic binder, and
• an organic solvent,
• to entirely coat a central cylindrical portion of said exterior circumferential surface;
• and
• heat treating said past to form a heat generating a resistor layer surrounding said central cylindrical portion.

A process of making a heating roller, comprising:

• preparing a cylindrical roller made of an electrically conducting material having an exterior circumferential surface made of said material;
• coating a central circumferential portion of said exterior surface of said material with an electrically insulating substance;
• applying to said central circumferential portion a paste comprised of:
• a glass frit,
• a powdered ruthenium compound,
• a powdered silver compound,
• an organic binder, and
• an organic solvent,
• to form a coating of said paste around said central circumferential portion;
• and
• heating said paste to form a heat generating resistor surrounding said central circumferential portion.

A process of making a heating roller, comprising:

• preparing a cylindrical roller made of an electrically conducting material having an exterior circumferential surface made of said material;
• applying to a central circumferential portion of said exterior surface of said material, an electrically insulating substance;
• heat treating said electrically insulating substance at a first temperature;
• applying to said central circumferential portion a paste comprised of:
• a glass frit,
• a powdered ruthenium compound,
• a powdered silver compound,
• an organic binder, and
• an organic solvent,
• to form a coating of said paste around said central circumferential portion;
• and
• heat treating said paste at a second temperature not exceeding said first temperature to form a heat generating resistor surrounding said central circumferential portion.