Method and apparatus for controlling phase-change ink-jet print quality factors

Abstract

A phase change ink transfer printing apparatus (10) applies a liquid intermediate transfer surface (12) to a heated drum (14, 28). Because the intermediate transfer surface is a thin liquid layer, molten ink drops (122) striking it flatten and spread out (110, 112, 114, 130) prior to cooling and solidifying as an ink image (26, 130) at the drum temperature. After the ink image is deposited, a print medium (21, 132), such as a transparency film, is fed into a nip (22) formed between the heated drum and an elastomeric transfer roller (23). As the drum turns, the print medium is pulled through the nip to transfer the ink image to the print medium. When in the nip, heat from the drum and print medium combine to heat the ink in accordance with a process window (90), making the ink sufficiently soft and tacky to adhere to the print medium but not to the drum. The ink drops comprising the ink image have a desired diameter to height ratio of from about 1.5:1 to greater than about 4:1 using the apparatus and method of printing disclosed. When the print medium leaves the nip, stripper fingers (24) peel it from the drum and direct it into a media exit path. No image post processing or fusing is necessary to achieve a high-quality print suitable for transparency projection.

Dependencies are inferred from the claim text.