Electrographic apparatus having improved developer metering construction
AssigneeEastman Kodak Company
InventorsDennis R. Kamp, James D. Walling
Life of this patent
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Abstract
Electrographic apparatus having an improved developer metering construction provides an elongated coil spring that extends across an applicator member's transport path (from the developer supply to the development zone) to meter and mix applied developer. Spring tension can be adjusted to control developer flow. In certain embodiments the spring provides a source of reference potential for and/or triboelectrically charges the developer and can enhance magnetic mixing of the developer.
Claims15
In electrographic apparatus in which an electrographic imaging member is moved past a development zone for development of an electrical image thereon, said apparatus including (1) developer supply means spaced from said development zone and (2) applicator means for transporting successive quantities of developer from said supply means into transfer relation with successive portions of said image member passing said development zone;
- an improved device for controlling the flow of developer during such transport, said device comprising:
- (a) an elongated coil spring having loops disposed along a longitudinal axis that extends across the path on which developer is transported from said supply means to said development zone;
- and
- (b) means for distending said spring along said longitudinal axis to provide passages therethrough for predetermined volumes of developer.
In an electrographic device of the type wherein an imaging member is moved past a development zone for image development, improved image development apparatus comprising:
- (a) developer supply means spaced from said development zone;
- (b) applicator means for transporting successive quantities of developer, on a external surface thereof, from said supply means to said development zone;
- (c) elongated spring means disposed along a longitudinal axis which extends across the path on which developer is transported from said supply means to said development zone and configured to form passages therethrough when stretched along said axis;
- and
- (d) means for longitudinally stretching said spring means to provide passages therethrough for predetermined volumes of developer.
Dependencies are inferred from the claim text.