发明名称 Electronic halftone generator
摘要 Method and apparatus for scanning a document original, either black and white or color, and reproducing a corresponding halftone reproduction thereof either locally or at a remote location. A halftone signal is generated by pulse width modulating or comparing the scanned, or video, signal with a periodic signal having two frequencies and phases to create a dot pattern output which is a function of the frequency and phase of the two combined modulating signals. The halftone reproduction generated has variable dot configurations that are controllable to enable both rotation of the dot pattern (screen angle) and geometric modifications of the dot pattern. If the document original is in color, light of three different colors is caused to scan the document, each resultant video signal being processed in a manner as set forth hereinabove. In a preferred embodiment, different screen angles are utilized for each color that comprises the reproduction.
申请公布号 US4149183(A) 申请公布日期 1979.04.10
申请号 US19760688669 申请日期 1976.05.21
申请人 XEROX CORPORATION 发明人 PELLAR, RONALD J.;GREEN, LELAND D.
分类号 B41M5/26;G03F5/00;H04N1/00;H04N1/405;H04N1/52;(IPC1-7):H04N1/40 主分类号 B41M5/26
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