基于网点结构的光学网点扩大特性研究

目的研究印刷品网点扩大中光学网点扩大特性,量化分析不同类型网点结构对光学网点扩大的影响差异,探讨光学网点扩大的一般规律。方法根据网点结构,提出周长对网点面积率敏感度的定义,以此分析光学网点扩大随网点结构特性的变化规律,图象栅格化处理器(RIP)输出多种网点结构,以不同网点胶印样张形式验证光学网点扩大规律。结果对于调幅网点,光学网点扩大大于机械网点扩大;对于调频网点,机械网点扩大大于光学网点扩大。同心圆网点是一种特殊网点结构,兼有调幅、调频光学扩大特性。结论光学网点扩大不可避免,光学网点扩大值与周长对面积率敏感度正相关,研究不同网点结构的光学扩大特性对印刷品质量控制有一定意义。

Properties of Optical Dot Dain Based on Dot Structure

The properties of optical dot gain of printings were researched. The differences in the influence of various dot structures on optical dot gain was quantitatively analyzed to explore the general law of optical dot gain. Based on dot structures, the definition of sensitiveness of circumference to dot area ratio was proposed, and the variation law of optical dot gain with dot structure characteristics was analyzed. Various dots were acquired through RIP. From the perspective of dot sensitiveness, the dot gain law was discussed and then demonstrated through offset printings. For AM dot, optical dot gain was more than physical dot gain. But for FM dot, physical dot gain was more than optical dot gain. Concentric dot owned special structures with properties of both AM and FM dot gain. Optical dot gain was inevitable and positively associated with the sensitiveness of circumference to dot area ratio. Research on the law of optical dot gain is significant to improve printing control.