激光打印字迹与书写字迹形成时序研究

Research on the Formation Sequence of Laser Printing Writing and Handwriting

【目的】通过对激光打印字迹和书写字迹不同交叉条件下的特征进行研究,为涉案文件中两种字迹交叉时序的检验提供分析依据。【方法】用不同粗细黑色签字笔以较轻和较重的笔压分别与激光打印字迹进行笔画交叉实验,形成若干份实验材料,然后运用反射变换成像技术分析交叉部位的特征。【结果】先打印后书写的情况下,交叉部位打印字迹的笔画连贯性被破坏,墨粉颗粒存在被划破、刮蹭、碾压的痕迹;先书写后打印的情况下,交叉部位打印字迹的墨粉颗粒平整地覆盖在笔痕凹陷处,打印字迹笔画连贯性完整;笔尖的粗细、笔压轻重都会对字迹交叉部位产生一定影响。【结论】通过反射变换成像技术可以判断激光打印字迹与书写字迹的形成时序,为解决此类时序检验问题提供直观、科学依据。

[Objective]The characteristics of laser printing writing and handwriting under different crossing conditions are studied to provide an analysis basis for the examination of the formation sequence of the laser printing writing and handwriting in the involved documents.[Method]A number of experimental samples were made by cross-stroke experiments with different thicknesses of black marker pens and laser printing writing with lighter and heavier pressure,and then the characteristics of cross-stroke were analyzed by reflection transformation imaging technology.[Results]In the case of printing first and then handwriting,the coherence of the laser printing writing at the cross part was destroyed,and the toner particles were scraped,scratched and crushed;in the case of handwriting first and then printing,the toner particles of the laser printing writing at the cross part are evenly and completely covered in the dent of the stroke mark.The thickness of the nib and the weight of the pen pressure will have a certain impact on the cross-stroke.[Conclusion]The formation sequence of laser printing writing and handwriting can be determined by reflection transformation imaging technology,which provides intuitive and scientific basis for solving such problems of sequence examination.