Empirical Study On The Image Characteristics Of Common Laser Printed Characters

Efficient office concept,so that the mechanism of printing documents more and more popular.The laser printer is now the most common document production tools,upgrading speed.From the point of view of the printed documents,there is a contradiction between the increasing demand for identification and the limited testing methods.The standard technical specification of document appraisal is the action guide of the present document inspection department.The inspection and appraisal of the mechanism document mainly depends on the information of handwriting.For the printing part of the document,such as adding or changing pages,handwriting information cannot be identified.The characteristic points of the mechanism are not easy to be detected and cannot be examined by using the traditional handwriting movement characteristics,which undoubtedly increases the technical problems and the inspection workload for the document examiners.This paper attempts to study the image characteristics of laser printed documents,that is,the common image characteristics of laser printed characters.By means of experimental verification,the characteristics of different laser printer brands are summarized to add auxiliary technical means to the inspection and identification of mechanism documents.The research is carried out in three stages.First,to understand the market situation,performance and user usage of laser printers and analyze the causes.Second,in order to make the sample more consistent with the actual situation,we visited the printer physical stores and other office places in Lanzhou science and technology street.According to the information of laser printers,design experimental samples,and collect the samples of common laser printers on the market.Third,the collected print samples are observed and recorded under the detection equipment,and summarized.This paper systematically analyzes and studies the character rule of the character image of laser printed document.A total of 151 samples were collected,involving 11 brands and 78 models of laser printers or laser multi-functional all-in-one machines.The sample forms include color printed plain text,black and white printed plain text,color printed pictures,and black and white printed pictures,which can basically reflect the use of common laser printer output text.The examination of the experimental samples is mainly from the perspective of trace science,using the document examination instrument and microscope to observe the image characteristics of the handwriting of each printed sample,and analyzing and summarizing the observed phenomena from the three aspects of printing ink,printing handwritin morphology and printing mark characteristics.In terms of the characteristics of secret symbols,it is found that there are great differences and regular characteristics in the secret symbols of various brands,and there are also differences in the forms of secret symbols among different brands,which can be used as the characteristic basis for the identification of brand species.No obvious characteristic rules were found in terms of morphological characteristics.Considering the difference in consumable cost,the morphological characteristics of each brand's handwriting did not reappear steadily.The research object of this paper is obtained from the printing sample of actual office units,and the use situation of each brand machine is different,so it can be more consistent with the actual case.To some extent,the results of the study can be used in practice to improve the accuracy of test.