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US 6,484,975 B1Granted
Method and apparatus to achieve uniform ink temperatures in printheads
AssigneeXerox Corporation
InventorsScott A. Elrod, Joy Roy, Richard G. Stearns, John S. Fitch
Life of this patent
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Abstract
A system for improving the uniformity of ink droplets delivered from a plurality of droplet sources on a printhead is described. The system includes a cooling system that compensates for nonuniform heating effects in a printhead which results in nonuniform temperatures. The distribution of the cooling system, and the effectiveness of the cooling system is set to maintain an approximately uniform ink temperature across the printhead.
Claims22
A printhead system comprising:
- a plurality of transducers distributed across a printhead, the transducers to deliver energy to ink flowing across a surface of the printhead;
- and
- a cooling system with a cooling effectiveness coupled to the printhead, the cooling system including a coolant flow over a second surface of the printhead and a detection system to detect a local temperature, the cooling system to locally adjust a flow of coolant in response to changes in the local temperature, the cooling effectiveness of the cooling system distributed across the printhead to approximately compensate for heating that results from the energy delivered by the transducers such that a temperature of the ink across the printhead is approximately constant.
A printhead system comprising:
- a plurality of transducers distributed across a printhead, the transducers to deliver energy to ink flowing across a surface of the printhead;
- and
- a cooling system with a cooling effectiveness coupled to the printhead, the cooling system including a coolant flow over a second surface of the printhead;
- and a detection system to predict future transducer activity, the detection system to adjust the coolant flow in anticipation of the future transducer activity, the cooling effectiveness of the cooling system distributed across the printhead to approximately compensate for heating that results from the energy delivered by the transducers such that a temperature of the ink -across the printhead is approximately constant.
1 more element
A method of improving a printhead output comprising the operations of:
- inputting ink into the printhead at a first temperature;
- delivering energy to the ink at a first transducer to form a droplet of ink, excess energy absorbed by the ink causing a rise in temperature of the ink to a second temperature in the proximity of the first transducer;
- and
- using a cooling system to cool the ink back to the first temperature while the ink flows from the first transducer to a second transducer, the cooling system to direct a cooling fluid flow over a surface of the printhead, a temperature of the cooling fluid adjusted to maintain an approximately constant cooling effectiveness.
1 more element
Dependencies are inferred from the claim text.