短波紫外反射法显现香烟外包装塑料薄膜表面潜在指印

杨鸣, 刘涛

刑事技术 ›› 2015, Vol. 40 ›› Issue (5) : 428-430. DOI: 10.16467/j.1008-3650.2015.05.021
技术与应用

短波紫外反射法显现香烟外包装塑料薄膜表面潜在指印

  • 杨鸣, 刘涛
作者信息 +

Development of Latent Fingerprint on BOPP Cigarette Packing Film by Shortwave UV Reflection Photography

  • YANG Ming, LIU Tao
Author information +
History +

摘要

短波紫外反射法广泛应用于潜在指印的显现,但对香烟盒外包装塑料薄膜上的潜在指印却无法得到较好的显现效果。香烟盒外包装塑料薄膜是一种无色透明且厚度薄的双轴拉伸聚丙烯(BOPP)薄膜,薄膜上的潜在指印往往较为微弱。短波紫外反射方法直接显现薄膜上的潜在指印时,大部分短波紫外光穿透了薄膜并被薄膜后面的物体反射,反射后的短波紫外光再次穿透薄膜,无法形成客体与痕迹之间有效的反差。本文在实验基础上提出了相应的改进方法,利用强吸收短波紫外介质完全吸收穿透薄膜的短波紫外光,使得穿透薄膜的短波紫外光不被薄膜后的物体反射从而突出显现存在于薄膜上的潜在指印痕迹。该方法通过控制照射时间可以最大限度的保持物证检材的原始状态,减少对后续DNA检验的影响。

Abstract

When cigarette wrapping film is made of Biaxially Oriented Polypropylene (BOPP), which is colorless, transparent and very thin, the “502” fuming method, a conventional way to develop the latent fingerprint on cigarette wrapping film, is not recommended for development of fingerprint on such film because of the steadfast adherence of the fingerprint’s ingredients onto the film surface over heat, negatively affecting the following DNA examination. Hence, the optical inspection is the most preferential choice for its non-destructiveness on the latent fingerprint development. The shortwave UV reflection photography is now widely applied to develop the latent fingerprint on a variety of substrates except the BOPP film unless a modification. The colorlessness, transparency and thinness of the film are found to be the main cause. When photograph being taken, most short-wave UV lights transmitting through the film are reflected back by the object behind the film to make the lights cross the film reversely. The reflected lights are stronger than the diffuse reflection lights produced by the latent fingerprint on cigarette wrapping film, leading a failure to form an effective contrast between the substrate and fingerprint. To solve this problem, this paper proposes a modified method by utilization of some strong short-wave UV absorbing medium such as print paper, thick glass and other similar materials, to let the transmitted UV lights completely absorbed behind the film. Therefore, the lights received by the UV camera or CCD are only the left diffuse reflection lights emitted by the latent fingerprint on cigarette wrapping film. Without the disturbance of the reflected lights, the latent fingerprint on the film can be obviously distinct under shortwave UV light radiation. Whereas be cautious to the irradiation time, otherwise the over-exposure to the radiation might hinder the subsequent DNA analysis.

关键词

指印 / 短波紫外反射照相 / 全波段CCD / BOPP薄膜

Key words

latent fingerprint / shortwave UV reflection photography / full-band CCD / BOPP film

引用本文

导出引用
杨鸣, 刘涛. 短波紫外反射法显现香烟外包装塑料薄膜表面潜在指印. 刑事技术. 2015, 40(5): 428-430 https://doi.org/10.16467/j.1008-3650.2015.05.021
YANG Ming, LIU Tao. Development of Latent Fingerprint on BOPP Cigarette Packing Film by Shortwave UV Reflection Photography. Forensic Science and Technology. 2015, 40(5): 428-430 https://doi.org/10.16467/j.1008-3650.2015.05.021

参考文献

[1] 杨飞,高树辉. 塑料袋表面502熏显指印的光学加强方法研究[J] . 中国人民公安大学学报:自然科学版, 2012(4):14-17.
[2] 王理珉,魏杰,胡群,等. 卷烟包装材料的应用及发展趋势[J] . 中国包装工业, 2004(9):36-38.
[3] 冯文静,杜春华. 我国BOPP薄膜生产现状及发展趋势[J] . 石油化工技术与经济, 2013(01):31-33.
[4] 王桂强. 指印的光学显现和照相技术[M] . 北京:群众出版社, 2001.
[5] 林景,王桂强,罗启龙. 短波紫外反射照相显现胶带粘面潜在指印[J] . 刑事技术, 2002(5):3-6.
[6] 刘涛,陶代琴. 观察紫外反射拍摄不同厚度透明玻璃表面汗液指印显现效果[J] . 刑事技术, 2014(2):52-54.
[7] 高婧宇,梁克伟,李鹏飞,等. “502”胶显现指纹后对脱落细胞DNA提取的影响研究[J] . 中国刑警学院学报, 2014(2):52-53.
[8] 邵丽芳,郝金萍,常柏年,等. 短波紫外照射对汗潜手印DNA检测的影响初探[J] . 刑事技术, 2012(1):24-26.
[9] 王昕,张艳云,王科,等. 刑事照相常用紫外光源照射对DNA检验的影响研究[J] . 刑事技术, 2013(1):38-41.

144

Accesses

0

Citation

Detail

段落导航
相关文章

/