Tektronix, Inc.

Bryan F Johnson

Nasser Alavizadeh

Douglas M Stanley

A multiple-orifice phase-change ink-jet print head (28, 44) is heated by a composite laminate heater (29, 58) having multiple heating zones (31-31K, Z1-Z28) spanning the X- and Y-directions of the print head. The print head has multiple rows of ink-jet orifices (34, 46) spread across its face in the Y-direction with the ink in each orifice in each row requiring substantially the same temperature to ensure a uniform jetting velocity from every orifice. In one embodiment, the print head is in fluid communication with a thermally massive multicolor ink reservoir (52) that conducts heat through a region of contact (92) with the print head. A rotating drum (32), spaced across a gap (90) from the print head, draws air through the gap thereby cooling the print head differentially in the Y-direction. Radiation and convection are further thermal transfer mechanisms that contribute to a nonuniform temperature throughout the print heads. The heating zones of the print head heaters compensate for the various thermal transfer mechanisms to cause a uniform temperature throughout the print heads. A temperature controller ( 16) requires only a single temperature sensor (18, 104) to regulate print head temperature.

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Aloha, OR, United States of America

Bryan F Johnson