Papers by Keyword: Laser Marking

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Authors: Jin Rui Li, Ai Qun Wang, Jian Mei Li, Yu Song Wu
Abstract: The image binarization of laser direct marking Data Matrix symbols on metal surface is a key procedure during recognition. Contrast and light uniformity of the symbols is greatly affected by the uneven illumination and reflection of the parts. To avoid the limitation of present binarized methods, an adaptive binarization method composed of Otsu method and Nearest neighbor pixels contributing threshold method is proposed. It takes global and local gray information into consideration, as well as the distribution of gray gradient. Experimental results show that the proposed method has a higher recognition rate and reliability.
1319
Authors: Xin Ming Zhang, Jing Qi Ma, Yun Feng Ding
Abstract: This document introduced the advantages of laser marking technology and the difficulty of marking glass surface. During used a laser marking machine which based on the latest super-pulsed CO2 laser and through marked texts on glass with three different ways, the results show the influence of different parameters in each marking method.
929
Authors: Chin Lung Chang, Jyun Wei Wu, Chia Yen Lee
Abstract: This paper presents a novel technique for coloring stainless steel utilizing a fiber laser. This study develops a processing technology that uses a fiber laser as a laser marking tool, and varies processing parameters such as pre-surface-processing conditions, stainless steel type, line distance, laser power, engraving speed, and laser pulse frequencies to achieve different results. This study investigates the results of the stainless workpiece coloring using optical microscope (OM). This study shows that polished stainless steel 316 exhibits the best engraving effect. With this material, the line distance, laser power, engraving speed, and pulse frequency of the laser change the oxidation thickness. The color of the processed workpiece also changes as the oxidation thickness changes due to the interference caused by the different thicknesses of the oxidation layers. Results prove that fiber laser processing of stainless steel is a promising and efficient technique for coloring stainless steel.
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Authors: Yu Fang, Dong Yun Wang, Qi Wei Yu, Yang Xiu Wei
Abstract: The existing laser marking control systems are mainly based on PC and PCI laser drivers. PC is used for editing marking information and extracting marking data. The rapid processing capacity of PC makes the laser making machine achieve faster processing speed. However, it cannot be used in the outdoors and bad situations. In older to make the laser marking system widely adapt to various environments, an embedded laser marking controller is developed. It is based on ARM9 and LINUX. It can be easily operated and can achieve wonderful marking.
407
Authors: Hua Dong Qiu, Chang Hou Lu, Wei Chen, Jian Mei Li
Abstract: Laser current is a key parameter in laser direct-part marking symbols on a substrate. Different laser current can create enormous impact on bar code contrast, but the influencing regularities are unclear. In this paper, a new significance test method based on the multivariate nonlinear model was proposed to investigate the influencing regularities. First, the multi-element nonlinear stepwise regression model between the laser current, the laser line spacing and symbol contrast was established, and then the model significance test was employed to evaluate the influence between the two factors and symbol contrast. Finally, the influencing regularities were found by comparing the influence between the laser current and the laser line spacing. These regularities are that along with the laser current value increasing the influence of laser current on symbol contrast decreases and that the effect is much smaller and can even be neglected when the laser current reaches or exceeds a certain value. This certain value is 15 A in the Nd:YAG laser Direct-part marking symbols on the aluminum alloy experiments.
197
Authors: Fei Chen, Zhao Yang Zhang, Yao Min Wang
Abstract: In the laser marking process system, a liquid crystal display (LCD) was used as the image mask, which can display dynamically and flexibly the various images by the programmable control. A nanosecond pulsed laser (1064nm) was applied to investigate the characteristic of laser photolithography fabrication technology. The light modulation function of LCD mask was firstly discussed by theory. By observing the graphics morphology with a high-powered optical microscope, it was found that the graphics of laser marking with LCD mask shows that its edges were not ablated but its line inside was ablated. According to analysis, the reasons of this phenomenon are due to the opaque lattice effect and the high light transmittance of black pixel. Results showed that the light modulation function of LCD mask was decided by adjusting the light transmittance with controlling the pixel voltage and a complete graphics was ablated in the range of 0.6J/cm2 ~ 0.8J/cm2.
633
Authors: Chun Ling Li, Chang Hou Lu
Abstract: The influences of laser processing parameters on the symbol contrast and surface roughness of Data Matrix barcodes were studied by single factor experiments using a Q-switched lamp pumped Nd:YAG laser. The orthogonal experiments were carried out to further study the relationship between laser parameters and surface roughness. Multivariate nonlinear regression analyses were performed based on the orthogonal experimental results and a mathematical relationship between parameters and surface roughness was established. The results show that the change trend of surface roughness is similar to symbol contrast with the increase of laser parameters. Both the average power and two different overlaps are important factors affecting the surface roughness and symbol contrast. But the current intensity has an insignificant impact on the surface roughness. The developed regression model can be used to predict the roughness of Data Matrix barcodes. This study can improve industrial application of laser direct part marking technology on titanium alloy substrates.
244
Authors: Jin Zhon Lu, Yong Kang Zhang, De Jun Kong, Su Min Yin, Jian Zhong Zhou, Ai Xin Feng
Abstract: The theoretical researches on fabrication, measurement and identification of laser marking system of 3D(three-dimension) anti-counterfeiting identifiers have been done in this paper. 3D identifiers were fabricated and 3D identifiers’ modelings were reconstructed, and binary coding of gray images were encoded by programmable control of liquid crystal mask, spatial modulating of laser beam and photolithography fabrication technics. We regarded the depth of 3D identifiers as anti-counterfeiting information, and the original marking data and anti-counterfeiting information are saved in remote database server by database technology and computer network technology,so true produces can be distinguished from fake through network. The basic theory of 3D nondestructive anti-counterfeiting identifiers based on liquid crystal mask was built, and a new technology of creating 3D anti-counterfeiting identifiers by laser shock wave was set up, which differs entirely from marking by laser ablation (or laser thermal effect). A new high-efficiency theory of detecting and identifying on 3D anti-counterfeiting identifiers by 3D identifiers’ reconstruction and binary coding was set up. The study enriches dynamic plastic deformation theory of partial high-strain-rate and anti-counterfeiting design & manufacturing theory which is also a highlight based on advanced manufacturing theory of mechanical effect on laser shock wave.
600
Authors: Chun Ling Li, Chang Hou Lu, Jian Mei Li
Abstract: In the application of laser marking, the biggest challenge is that machine-readable barcodes with superior quality were not marked consistently. To solve this problem, laser direct-part marking Data Matrix barcode experiments were carried out on titanium alloy substrates, using a Q-switched light-pumped Nd:YAG laser. The microstructure of the symbols was analyzed using an environmental scanning electron microscope (ESEM). The internal micro-stresses of the marked areas were analyzed using X-ray diffractometer (XRD). The influence of the pulse frequency on the symbol contrast is analyzed. Results showed the interaction between the laser and the titanium alloy can be found. This can further explain the physical mechanism of laser direct part marking Data Matrix symbols on titanium alloy substrates.
194
Authors: Oksana Ganzulenko, Ani Petkova
Abstract: The article is devoted to some aspects of laser marking technology for machine parts. We consider the local impact zone effect of the pulse laser beam on the surface of metal materials. The results describing the influence of process parameters on the quality of the being marked images by pulsed laser are submitted. The examples of using barcode marking on several materials for machine parts in selected technological modes of installation are given.
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