Electrographic development method and apparatus
AssigneeEastman Kodak Company
InventorsEdward Michael Eck, Thomas Joseph Foster
Life of this patent
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Abstract
The invention relates generally to processes for electrographic image development. An electrographic development apparatus is provided wherein a film is adjacent a cylindrical toning shell and a mixture of toner and carrier is particles disposed on the cylindrical toning shell in contact with the film. The cylindrical toning shell is closest to the film at a first location, the mixture of toner and carrier particles being movable through the first location with a flow direction. A magnetic core disposed within the cylindrical toning shell offset toward the cylindrical shell such that a magnetic field strength is greater at the second location than the first location.
Claims42
An electrographic development apparatus, comprising:
- a film;
- a cylindrical toning shell having an toning shell outer circumference;
- a mixture of toner and carrier particles disposed on the cylindrical toning shell in contact with the film;
- the cylindrical toning shell being closest to the film at a first location,
- the mixture of toner and carrier particles being movable through the first location with a flow direction;
- and
- a magnetic core disposed within the cylindrical toning shell that provides a magnetic field strength of varying magnitude around the toning shell outer circumference,
- the magnetic field strength having a first time-averaged absolute magnitude at the first location, and
- a second time-averaged absolute magnitude at a second location a distance from the first location in the flow direction,
- the second time-averaged absolute magnitude being at least 25 gauss greater than the first time-averaged absolute magnitude.
An electrographic development apparatus, comprising:
- a film;
- a cylindrical toning shell having an toning shell outer circumference;
- a mixture of toner and carrier particles disposed on the cylindrical toning shell in contact with the film;
- the cylindrical toning shell being closest to the film at a first location,
- the mixture of toner and carrier particles being movable through the first location with a flow direction;
- and
- a magnetic core disposed within the cylindrical toning shell that provides a magnetic field strength of varying magnitude around the toning shell outer circumference,
- the magnetic field strength having a first time-averaged absolute magnitude at the first location, and
- a second time-averaged absolute magnitude at a second location a distance from the first location in the flow direction,
- the second time-averaged absolute magnitude being at least 2.5% greater than the first time-averaged absolute magnitude.
An electrographic development method, comprising:
- moving a mixture of toner and carrier particles disposed on a cylindrical toning shell in contact with a film in a film direction through a first location wherein the cylindrical toning shell is closest to the film,
- a magnetic core being disposed within the cylindrical toning shell that provides a magnetic field strength of varying magnitude around the toning shell outer circumference,
- the magnetic field strength having a first time-averaged absolute magnitude at the first location, and
- a second time-averaged absolute magnitude at a second location a distance from the first location in the flow direction,
- the second time-averaged absolute magnitude being at least 25 gauss greater than the first time-averaged absolute magnitude.
An electrographic development method, comprising:
- moving a mixture of toner and carrier particles disposed on a cylindrical toning shell in contact with a film in a film direction through a first location wherein the cylindrical toning shell is closest to the film,
- a magnetic core being disposed within the cylindrical toning shell that provides a magnetic field strength of varying magnitude around the toning shell outer circumference,
- the magnetic field strength having a first time-averaged absolute magnitude at the first location, and
- a second time-averaged absolute magnitude at a second location a distance from the first location in the flow direction,
- the second time-averaged absolute magnitude being at least 2.5% greater than the first time-averaged absolute magnitude.
Dependencies are inferred from the claim text.