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US 5,808,631 AGranted
Integrated fault tolerance in printing mechanisms
AssigneeEastman Kodak Company
InventorKia Silverbrook
Life of this patent
Estimating the term…
Abstract
Printing heads with a multitude of printing actuators which also include integrated drive circuitry can have poor manufacturing yield and reduced operating life caused by the high probability of defects associated with large active chip areas. A printing head is disclosed which includes fault tolerance circuitry consisting of redundant shift registers and voting circuits which is able to compensate for manufacturing defects and field failures in the data transfer circuits.
Claims18
An integrated printing head which includes a plurality of marking means, each having an associated driver circuit, said printing head further including:
- (a) a plurality of data transfer mechanisms which, in the absence of faults, transfer correspondingly identical data to corresponding voting circuits;
- (b) a voting circuit means coupled to each driver circuit, for determining the status of the majority of the data transfer mechanisms;
- (c) whereby said driver circuits will energize their associated marking means depending upon the output of their respective voting circuit.
Dependencies are inferred from the claim text.