| 摘要 |
A method of screening halftone image motifs, in which method the picture halftones of the halftone image motif are reproduced by changing the intensity of the structure of a basic screen structure of any form. The allocation of the picture halftone area of the halftone image motif to the intensity of the screen structure reflecting this picture halftone area can be specified in a targeted manner. In a phototechnical version of the inventive method (Figure 1), any desired basic screen structure (1) is made and expanded screen structures are made from it as negative films (9, 11). From the image motif (13) to be screened, the same number of tone value extracts (20, 22) is produced as negative films, each of which reproduces a particular picture halftone area of the halftone image motif which can be adjusted by the exposure time. The tone value extracts (22, 20) are exposed with the expanded screen structures (9, 11), assigned to them in each case, of the row onto a strip material (24) which then reproduces the screened image motif in such a way that the picture halftone proportions defined by the tone value extract are reproduced locally by the intensity of the screen structure assigned thereto. Of this method there are several phototechnical and EDP-scanner-laser variants which are suitable for screening halftone image motifs, for producing screened printing copies and for printing on recording media with image motifs screened in this manner. <IMAGE>
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