光学变色油墨的颜色测量方法研究  

Color Measurement Methods for Optically Variable Ink

作　　者：公绪平 黄敏[1] 沈跃桐 魏子文 李修[1] 刘瑜[1] Gong Xuping;Huang Min;Shen Yuetong;Wei Ziwen;Li Xiu;Liu Yu(School of Printing and Packaging Engineering,Beijing Institute of Graphic Communication,Beijing 102600,China)

机构地区：[1]北京印刷学院印刷与包装工程学院,北京102600

出　　处：《光学学报》2023年第22期180-187,共8页Acta Optica Sinica

基　　金：国家自然科学基金(61675029);北京印刷学院科研创新团队项目(BIGCEc202302)。

摘　　要：为确定光变油墨颜色测量的几何条件,选用不同企业提供的22个基于光变油墨印制的匀色色块,使用X-Rite MAT12多角度分光光度计进行样品的颜色测量。结果表明,在15°:0°(as15°)、45°:-60°(as-15°)测量条件下的油墨色度值与油墨生产商标定的颜色变化效果较为一致,但现有测量条件不能全面表征光变油墨的颜色变化范围。进一步地,使用R1角分辨光谱仪基于自定义的(α,β)测量条件进行样本的光谱测量,提出选用5°:0°(as5°)和60°:-55°(as5°)测量条件可测得光变油墨的最大色调变化范围。基于22个样本在不同角度下的饱和度测量结果,拟合得到45°:-40°(as5°)测量条件下可测得光变油墨较大饱和度值。使用上述3个测量条件,可全面表征光变油墨颜色再现的属性,同时也可进行不同品牌光变油墨的防伪鉴定。Objective The gonio-chromatic attributes of optically variable ink(OVI)lead to its extensive applications in anticounterfeit printing,such as confidential documents,banknotes,and packaging products.Products printed with this ink exhibit a notable color-changing effect when observed from various angles.Although current color measurement standards specify a large number of measurement geometries,there is a lack of research on assessing the efficacy of these conditions for OVI.Consequently,manufacturers rely on subjective evaluations for determining the color-changing effects of OVI,resulting in substantial uncertainty in the quality control of anti-counterfeit products.Thus,it is imperative to conduct a systematic study on the color measurement methods of OVI to accurately capture the color-changing effects of OVI.Methods We employ different color measurement instruments to test measurement geometries on 22 OVI samples,supplied by ink manufacturers.The employed measurement geometries are extensively adopted for gonio-apparent object characterization,following the notation stipulated in the ASTM E2539-14.Initially,the OVI microstructure is observed at 400×magnification using a 3D laser confocal microscope,and images are captured by a Canon EOS 760D camera in measurement geometries of 45°:-60°(as-15°),45°:-30°(as15°),15°:-30°(as-15°),15°:0°(as15°).Then,the X-Rite MAT12 multi-angle spectrophotometer is leveraged to measure the spectral power distributions and chromaticities of the samples in 12 geometries.These results are utilized for evaluating the geometries recommended by international standards.Finally,the influence of measurement variablesαandβon OVI chromaticity is investigated by customizing 28 different geometries using an R1 angle-resolved spectrometer to find the optimal measurement geometries for OVI.Results and Discussions Images captured in four measurement geometries using a 3D laser confocal microscope and a Canon EOS 760D are compared with the color-changing effects labeled by manufactu

关 键 词：视觉光学 视觉色彩 光变油墨 颜色测量 

分 类 号：O436[机械工程—光学工程]