著者

三品 博達 田中 恒雄

出版者

社団法人 日本印刷学会

雑誌

日本印刷学会論文集 (ISSN:00400874)

巻号頁・発行日

vol.21, no.1, pp.13-21, 1983

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A New image modulation process for printing by means of laser speckle pattern is proposed and analysed theoretically by standing on optical and staitistical base. In this method, image plane laser speckle pattern is used for the modulation in a platemaking process instead of usual contact or glass screesn. It can be shown that the characteristics of image modulation in this process are closely related to the first order statistics of laser speckle which represent the intensity probability distribution function.<br>By considering the platemaking and printing process, the relation between the density of the original and printed image is obtained for various surface roughness and different parameters of optical system. As the results, the widest and most linear reproduction curve is given when the speckle pattern having the contrast value of 0.5 is used for image modulation. The screen range of speckle modulation depends strongly on the ratio of the threshold level of the sensitized plate to the average intensity level of the speckle pattern.

著者

北尾 奈穂子 奥平 純子 田中 恒雄 青柳 象平 内山 茂久 安藤 正典

出版者

社団法人大気環境学会

雑誌

大気環境学会年会講演要旨集

巻号頁・発行日

no.43, 2002-09-11

著者

田中 恒雄

出版者

紙パルプ技術協会

雑誌

紙パ技協誌 (ISSN:0022815X)

巻号頁・発行日

vol.49, no.5, pp.813-820, 1995-05-01 (Released:2009-11-16)

参考文献数

41

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In order to expect the feasible printing conditions to obtain high definition image by modern printing technology, physical properties of paper surfaces relating ink transfer are mainly discussed due to the experimental data accumulated thus far. The macroscopic structures of paper surfaces depending on the porosity, the smoothness, the compressibility and so on, are responsible for the tone rendering by small halftone ink dots the size of which reaches about 10 μm. To control the dot gain to be minimum is essential in the high definition printing process. However, the dot gain formation seems prone to be made by the rheological properties of printing ink rather than by the properties of paper surfaces mentioned above. Also, the thickness control of ink film is much more important in the process as compared to that in the ordinary halftone reproduction process.