拉曼光谱法检验激光打印文字与印文朱墨时序问题研究

发布时间：2018-01-23 23:28

本文关键词： 拉曼光谱法激光打印机印文朱墨时序　出处：《中国政法大学》2017年硕士论文　论文类型：学位论文

【摘要】：在文件检验的领域中,朱墨时序的鉴定是很重要的一个方面。过去很长一段时间,在涉及朱墨时序鉴定的案件中,通常采用的检验方法有切开法、显微镜检验法等。传统的检验方法很大一部分依靠司法鉴定人员的经验以及专业素质,司法鉴定的结果容易受到主观方面的影响,准确率偏低,外界很容易质疑文书司法鉴定的科学性。有损的检验方法也不适用于重要文书的鉴定。而且,当激光打印文字层与印文层比较薄的时候,采用以上检验方法判断朱墨时序变得极其困难。目前,无损检验方法已经成为发展趋势。随着科技的发展和进步,激光打印机走进了日常的办公和生活中,那么问题随之而来,激光打印文件的数量增多,那么与此相关的违法犯罪活动也日益增多,其中朱墨时序的案件占很大一部分比例。实践中,需要一种能适应司法鉴定的准确率高的无损检验方法。基于上述背景,笔者搜集了不同品牌、不同型号的27种激光打印机的打印文字的实验样本27份和20种印文的实验样本20份,采用拉曼光谱法分别测试各个实验样本的拉曼光谱图;同时搜集了其中25种激光打印机打印文字和20种印文先朱后墨、先墨后朱的实验样本共计1000份,采用拉曼光谱成像技术分别测试各个实验样本的拉曼光谱成像图。探索拉曼光谱成像技术在文件检验领域朱墨时序鉴定方面的效果,分析不同激光打印机的品牌和不同印文材料对检验结果的影响。通过实验得出以下结论:第一,实验一建立了激光打印文字墨迹的拉曼光谱数据库,并依据谱图将其分为七类(见表3),而且分析得知激光打印文字墨迹的成分和品牌没有关系,采用拉曼光谱法可以区分不同物质成分的激光打印文字墨迹;第二,实验二建立了印文的拉曼光谱数据库,并依据谱图将其分为十一类(见表6),而且分析得知印文色料的成分和种类没有关系,采用拉曼光谱法可以区分不同物质成分的印文;第三,实验三采用拉曼光谱成像技术检验激光打印文字墨迹和印文的朱墨时序,取得了较好的成果,可以分析判断朱墨时序。并且发现拉曼光谱成像技术在区分激光打印文字墨迹和印泥、印油、光敏印油和原子印油等种类印文的朱墨时序方面的检验效果不太一样,检验激光打印文字墨迹和印泥印文朱墨时序的效果最好。最后,基于上述研究,本文针对拉曼光谱法检验激光打印文字与印文朱墨时序的相关问题提出几点建议和反思。并在本论文的第五章例举了法大法庭科学技术鉴定研究所之前鉴定过的有关朱墨时序的一则案例,通过采用拉曼光谱成像技术检验鉴定检材,鉴定的结果验证了拉曼光谱成像技术在朱墨时序鉴定方面的可行性。
[Abstract]:In the field of document inspection, the identification of the timing of Zhu and Mo is an important aspect. In the past a long time, in the cases involving the timing identification of Zhu and ink, the method of opening is usually used. The traditional testing methods depend on the experience and professional quality of forensic experts. The results of judicial identification are easy to be affected by subjective aspects and the accuracy is on the low side. It is very easy for the outside world to question the scientific nature of the judicial identification of the document. The damaging test method is also not applicable to the identification of important documents. Moreover, when the laser print writing layer and the print layer are thin. It is very difficult to judge the timing of Zhu ink by the above methods. At present, the nondestructive testing method has become a trend. With the development and progress of science and technology, laser printers have entered into the daily office and life. Then the problem followed, the number of laser printing documents increased, then the related criminal activities are also increasing, among which Zhu Mo timing cases account for a large proportion. In practice. Need to be able to adapt to the high accuracy of forensic non-destructive testing method. Based on the above background, the author collected different brands. There are 27 experimental samples of 27 kinds of laser printers and 20 experimental samples of 20 kinds of printed characters. The Raman spectra of each experimental sample are measured by Raman spectroscopy. At the same time, 25 kinds of laser printer printed text and 20 kinds of printing text first Zhu and then ink, first ink and then Zhu experimental samples, a total of 1000 samples. Raman spectroscopic imaging technique was used to test the Raman spectrum images of each experimental sample, and to explore the effect of Raman spectrum imaging technology in the field of document verification in the field of time sequence identification of Zhu ink. The effects of different brands of laser printers and different printing materials on the test results are analyzed. The following conclusions are drawn through the experiment: first, the Raman spectrum database of laser printed ink is established in experiment 1. According to the spectrum, it is divided into seven categories (see Table 3), and the analysis shows that the composition of laser print ink has no relationship with the brand. The Raman spectrum method can distinguish the different material components of laser print ink. Second, the second experiment establishes the Raman spectrum database of the printed language, and divides it into eleven categories according to the spectrum (see Table 6), and the analysis shows that the composition and the type of the printing pigment have no relation. Raman spectroscopy can be used to distinguish the printing of different material components. Third, the third experiment uses Raman spectrum imaging technology to test the sequence of ink and ink in laser print, and good results have been achieved. We can analyze and judge the time sequence of ink, and find that Raman spectroscopy imaging technology is used to distinguish between laser print ink and print slime and printing oil. Guang Min printing oil and atomic printing oil and other types of printing ink time sequence test effect is not the same, laser print ink and mud printing ink timing is the best. Finally, based on the above research. In this paper, some suggestions and reflections are put forward to examine the time sequence of laser printed text and printing ink by Raman spectroscopy. In the 5th chapter of this paper, the author gives an example of the identification before the Institute of Science and Technology Appraisal of the French Court of Justice. A case about the timing of Zhu and Mo. The feasibility of Raman spectroscopy imaging in the timing identification of ink and ink was verified by the results of Raman spectrum imaging.
【学位授予单位】：中国政法大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：D918.92

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