• Journal of Welding and Joining
• /
• v.12 no.2
• /
• pp.20-27
• /
• 1994

The laser marking system is widely used in many industrial manufacturing companies as an effective process, because it is versitile, clean, and fast to run. Minimal heat deformation and zero tool wear can be obtained using fast and non-contact process of laser marking. As an introductory level, the basic knowledges about laser marking system layout and its components are presented with diagrams. The effects, requirements, and application example of laser marking process are also described in this paper.

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.1
• /
• pp.79-84
• /
• 2003

A light guide panel is an element of the LCD backlight module that is often used for the display of compact electronic devices. In this study, a laser marking system is proposed to fabricate light guide panel, which can replace other manufacturing methods such as silk printing, stamping, or v-cutting methods. The objective of this research is to evaluate the process parameters of the laser marking system. Light guide patterns were marked with a 50W $CO_2$ laser (CW) to understand the effects of average power and scanning speed on the geometry and quality of groove pattern. The width of the fabricated grooves increases with increasing laser power and decreasing scan speed. In order to analyze surface characteristics and optical properties (luminance, uniformity), SEM photography and BM7 (luminance measuring system) were used. As a result, the optimal conditions of the process parameters were determined.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.3
• /
• pp.213-218
• /
• 2017

In this study, a reverse design of the F-theta lens was proposed for a 2D scanner in remote welding applications. The curvature and distance of the lens were set as variables, and the focal length of the lens was set as the marginal ray height. The ZEMAX commercial software was used to perform a simulation with unlimited iterations for the optimization process. The target value was optimized using the internal Merit function with the weight factors of focal length and spot diameter. The number of lenses was four, and the focal length obtained from the results was 135mm that is slightly less than that of the commercial lens, which is set with a focal length of 185 mm. The calculated spot diameters are $1.3{\mu}m$, $6.2{\mu}m$, and $16.1{\mu}m$ for $0^{\circ}$, $12.5^{\circ}$ and $23^{\circ}$ of incident laser beam, respectively. It is expected that an optimized lens design is possible by performing the reverse design of a lens by the ray tracing method.

• Journal of the Korean Society for Precision Engineering
• /
• v.22 no.7 s.172
• /
• pp.27-37
• /
• 2005

Direct writing technology on the silicon wafer surface is used to reduce the size of the chip as the miniature trend in electronic circuit. In order to improve the productivity and efficiency, the real time quality estimation is very important in each semiconductor process. In laser marking, marking quality is determined by readability which is dependant on the contrast of surface, the line width, and the melting depth. Many researchers have tried to find theoretical and numerical estimation models fur groove geometry. However, these models are limited to be applied to the real system. In this study, the estimation system for the line width during the laser marking was proposed by process monitoring method. The light intensity emitted by plasma which is produced when irradiating the laser to the silicon wafer was measured using the optical sensor. Because the laser marking is too fast to measure with external sensor, we build up the coaxial monitoring system. Analysis for the correlation between the acquired signals and the line width according to the change of laser power was carried out. Also, we developed the models enabling the estimation of line width of the laser marking through the statistical regression models and may see that their estimating performances were excellent.

• The Journal of the Korea Contents Association
• /
• v.18 no.6
• /
• pp.303-313
• /
• 2018

The purpose of this study is digitalization of earthwork such as development of 3D terrain analysis platform using latest technologies including unmanned aerial vehicle and terrestrial laser scanner to ultimately achieve earthwork automation. It is necessary to develop related element technologies and to establish regulations so that it can be applied to the domestic construction projects. As a result of pilot project about the earthwork surveying automation technology, it was confirmed that information such as terrain coordinates, soil, boring, and excavation volume is acquired smoothly. In this paper, we investigate related regulations and manuals in Japan and propose the improvement plan of domestic regulation. We plan to study regulations from early to final construction stage, combine with the 'regulation for public surveying', and improve the regulations in detail.

• Journal of Institute of Control, Robotics and Systems
• /
• v.10 no.4
• /
• pp.304-311
• /
• 2004

In this paper we present a technique of discrete-time sliding mode controller design for assigning eigenvalues of sliding mode and determining a convergence rate to sliding surface. First the sliding mode coefficient is designed via Ackermann s formula. Then a linear controller is designed to enforce sliding mode such that the resulting closed loop yields the desired eigenvalues. As we use a linear control instead of nonlinear control, chattering is nearly eliminated. Simulation and experimental results are included to show the effectiveness of the proposed method for Laser Marking System.

• Proceedings of the Korea Contents Association Conference
• /
• 2010.05a
• /
• pp.488-490
• /
• 2010

Recently demand for the titanium material has been increasing continuously, and the titanium material is being applied to various fields these days. Especially, in the jewelry filed, the diamond set titanium jewels begin to appear. In this paper, the authors introduce advanced material titanium jewels by various expression techniques and propose the wedding jewel design using titanium material, practical and 'ECO-Steel'.

• Journal of Institute of Convergence Technology
• /
• v.3 no.2
• /
• pp.39-43
• /
• 2013

Titanium has been used to satisfy various applications such as bio engineering, aerospace, electronics, automobile. Recently, micro fabrication technologies of metals such as titanium have been required to satisfy many conditions in various fields. To satisfy these demands, micro electrochemical process using laser marking can be an alternative method because it is one of the precision machining and efficient process. Micro electrochemical process using laser marking needs to accomplish form of the oxidized recast layer on metal surface by laser marking. The laser beam marking conditions such as average power, pulse repetition rate and marking speed should be properly selected to form oxidized recast layer. So, the characteristics of titanium surface according to laser marking conditions was investigated through SEM(scanning electron microscope), EDS(energy dispersive spectrometer) and surface roughness analysis.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.728-731
• /
• 2005

A light guide panel (LGP) is an element of the LCD back light unit, which is used for display devices. In this study, a laser marking process is applied to the fabrication of light guide panels as the new fabrication process. In order to obtain a light guide panel which has high luminance and uniformity, four principal parameters such as power, scanning speed, ratio of line gap, and number of line were selected as important factors. A Web-based design tool was developed to generate patterns of light guide panel, and the tool may assist the designer to develop optimized patterns. Topcon-BM7 was used for luminance measurement of each specimen 100mm$\times$100mm area. By Taguchi method optimized levels of each parameters such as 40W of power, 30mm/s of scanning speed, 100:50 ratio of pattern gap, and 90 line of pattern were found by Taguchi method.

• Archives of design research
• /
• v.18 no.2 s.60
• /
• pp.303-314
• /
• 2005

This study is intended to promote local woodcraft industry with revitalization of local festival in Inje-county. To do so, we propose the travel souvenir design with local identity and the plan for production and marketing based on the management of 'Design Hospital' and the building of production method through 'laser wood inlaying technique like puzzle style'. Research method is benchmarking analysis of successful cases of travel souvenir which is developed for cultural contents of local festival. The result of this study is the following. First, design outsourcing is done one of support in industry focused on old boy network, Through it, Special brain of design can be supplied without compensation. Also the difficulty of manpower problem is lessened and the ability of product development in short term can be guaranteed. On the basis of this, we are able to apply Mass Customization production by up to date digital production method. This enables us to maintain the production flexibility of cultural goods fit for the traits of local festival. This study is intended to present the best model guananteeing both profit of wood technological industry and the possibility of local cultural.