Tektronix, Inc.

Xerox Corporation

James D Padgett

Trevor James Snyder

Terrance Lee Stephens

David Paul Platt

Ronald F Burr

Hue Phuoc Le

David R Koehler

James D Buehler

Jon C Mutton

Meade M Neal

A J Rogers

Wayne Jaeger

Gray scale ink jet printing method and apparatus produce a high quality image having varying color intensities. This is achieved by mixing a colored phase change ink with varying amounts of a clear phase change ink base, thereby producing multiple gray scale levels of each color. The mixing either can be performed prior to placement of the phase change ink in the printer, or can be performed within the printer to produce different levels of color intensity during the printing process.

Method and apparatus for producing ink intensity modulated ink jet

An improved media-width phase-change ink-jet print had (102) maintains a uniform temperature across its width to produce consistent drop mass and uniform print quality. The print head uses a heater (120) including two separately controlled, overlapping heating zones (154). The heating zones produce heat gradients (170, 172) that have maximum outputs toward opposing edges (168a, 168b) of the print head and are controlled in response to thermistors (138s, 168b) positioned at the corresponding edges. The two heating zones together produce a linear heat gradient (180) across the print heat to compensate for uneven head-to-drum spacing (166) and other unsymmetrical thermal loads on the print head. The improved print head also includes baffles (192) that reduce air flow between the head and the attached reservoir (118), and thermal breaks (218) that insulate the section (220) of the head that includes the jets from the thermal gradients at the edges of the print head.

Ink-jet print head having improved thermal uniformity

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Portland, OR, United States of America

James D Padgett