Copy indicator for a document
作者： Douglas C. Gordon
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摘要: A printed background pattern for a document is described, wherein the masks copy indicator which revealed upon making of using digital optical scanning means. The comprises an area microprinting with type size having line resolution about 20% to 80% resolving power Preferably, less than 100 μm. An solid printing provided within defines indicator. lines have visual value approximating that so as be masked therein, and are capable by
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