Printhead apparatus having digital delay elements and method therefor
AssigneeHewlett-Packard Company
InventorsDennis J. Schloeman, Jeffery S Beck, Adam L Ghozeil
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Abstract
Printhead and printer arrangements that provide digital delay between firing signals for a common firing interval. The delay achieves a controlled, staggered generation of firing signals that reduces EMI and instantaneous power supply draw and reduces or eliminates certain shielding requirements. Various arrangements are provided, including the use of edge triggered digital delay elements, staggered firing signal generation from firing signal control logic and the use of analog delay elements.
Claims21
A printhead apparatus, comprising:
- a substrate;
- a plurality of ink expulsion elements formed on said substrate and arranged in at least a first group and a second group;
- a firing signal conductor coupled to each of said ink expulsion elements;
- and
- a digital delay element provided in said firing signal conductor between said first and said second groups of ink expulsion elements that within a common firing interval achieves a delay in the receipt of a firing signal at said second group relative to said first group.
A printhead apparatus, comprising:
- a substrate;
- a plurality of ink expulsion elements formed on said substrate;
- a firing signal conductor coupled to each of said ink expulsion elements;
- and
- a mechanism coupled to said firing signal conductor for inducing within a common firing interval a digital delay between receipt of a firing signal at one of said ink expulsion elements relative to the receipt of that firing signal at another of said ink expulsion elements to reduce EMI.
A method of mechanized printing, comprising the steps of:
- providing a printhead having multiple ink expulsion elements;
- generating firing signals for said ink expulsion elements;
- and
- producing said firing signals such that within a common firing interval at least some of said firing signal are digitally delaying relative to other firing signals.
Dependencies are inferred from the claim text.