刑事技术
刑事技術
형사기술
FORENSIC SCIENCE AND TECHNOLOGY
2015年
4期
291-295
,共5页
文件检验%时序%激光打印%印文%荧光
文件檢驗%時序%激光打印%印文%熒光
문건검험%시서%격광타인%인문%형광
questioned documents%sequence%laser printing%stamped seal impressicm%fluorescence
目的:研究如何运用紫外荧光检验激光打印文字与盖印印文的形成时序,为鉴别此类案件提供新的、无损、快速、可靠的检验方法。方法使用 VSC5000文件检验工作站,采用不同紫外光对72份实验样本进行照射和透射检验,并调整滤色片、对比度、亮度等参数,观察“先朱后墨”和“先墨后朱”两种时序条件下的荧光反映。结果两种时序条件下,打印文字与盖印文字交叉处的荧光反映存在较大差别。在先墨后朱时序下,打印文字在交叉处笔画颜色变深、宽度增加,但能保持相对完整;在先朱后墨时序下,打印文字在交叉处笔画颜色、宽度没有变化,但部分笔画可能存在中断或不完整现象。结论运用荧光法能准确判定激光打印文字与盖印印文的形成时序,该方法可应用于实践案件鉴定工作。
目的:研究如何運用紫外熒光檢驗激光打印文字與蓋印印文的形成時序,為鑒彆此類案件提供新的、無損、快速、可靠的檢驗方法。方法使用 VSC5000文件檢驗工作站,採用不同紫外光對72份實驗樣本進行照射和透射檢驗,併調整濾色片、對比度、亮度等參數,觀察“先硃後墨”和“先墨後硃”兩種時序條件下的熒光反映。結果兩種時序條件下,打印文字與蓋印文字交扠處的熒光反映存在較大差彆。在先墨後硃時序下,打印文字在交扠處筆畫顏色變深、寬度增加,但能保持相對完整;在先硃後墨時序下,打印文字在交扠處筆畫顏色、寬度沒有變化,但部分筆畫可能存在中斷或不完整現象。結論運用熒光法能準確判定激光打印文字與蓋印印文的形成時序,該方法可應用于實踐案件鑒定工作。
목적:연구여하운용자외형광검험격광타인문자여개인인문적형성시서,위감별차류안건제공신적、무손、쾌속、가고적검험방법。방법사용 VSC5000문건검험공작참,채용불동자외광대72빈실험양본진행조사화투사검험,병조정려색편、대비도、량도등삼수,관찰“선주후묵”화“선묵후주”량충시서조건하적형광반영。결과량충시서조건하,타인문자여개인문자교차처적형광반영존재교대차별。재선묵후주시서하,타인문자재교차처필화안색변심、관도증가,단능보지상대완정;재선주후묵시서하,타인문자재교차처필화안색、관도몰유변화,단부분필화가능존재중단혹불완정현상。결론운용형광법능준학판정격광타인문자여개인인문적형성시서,해방법가응용우실천안건감정공작。
Objective This paper aims to demonstrate a new, non-destructive, quick and reliable way for determining crossing sequence of laser printed text and stamped seal impression using ultraviolet fluorescence. Methods A Video Spectral Comparator (VSC5000) was applied. 72 document samples, prepared with 6 brands of laser printer and 3 types of inkpad, were examined under ultraviolet light with adjustment of parameters including color filter, contrast, brightness and others. Then fluorescence reflection on overlapping region of seal impression and printed text was observed. Results There was great difference at two crossing sequences, that is, printed text over seal impression and seal impression over printed text. In the crossing region of seal impression over printed text, the text was darker and wider, but the strokes maintained continuous and complete. In the crossing region of printed text over seal impression, the text kept the same color and width with those separated from the stamp impression, but some of them were interrupted or incomplete. Conclusions The ultraviolet fluorescence method is a very effective and attractive technique for determining the sequence of laser printed text and stamped seal impression. Some challenging samples such as year-long documents, unclear stamps, and those not covered yet here, can be detected in further study.