• Title/Summary/Keyword: laser engraving

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Laser Engraving of Plasma Sprayed Ceramic Coatings (플라즈마 용사된 세라믹 코팅층의 레이저 홈가공)

  • S.Y. Bang
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.1
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    • pp.142-149
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    • 1997
  • Ceramic-coated anilox roll for printing is resistant to corrosion and wear, and hence has enhanced life and quality. Laser engraving is used typically for machining holes to store ink in this roll. Since engraved hole size and shape are directly related to laser processing parameters, it is necessary to know the rela- tionships among these parameters. In this study, the parameters for engraving of ;oasma sprayed ceramic coatings with Nd:YAG laser were studied. Relationships between hole shape and processing parameters were analyzed. Cr$_{2}$O$_{3}$ceramic was found to be most suitable for Nd:YAG laser engraving. It was found that hole depth can be increased by using higher energy pulses. Effect of using different assistant gases was small to the final results. For better results, it was suggested to use a very stable laser with shorter pulses and higher pulse energy.

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Improvement of Light Guide Panel Performance by Laser Patterning (레이저 가공에 의한 백라이트 도광판 성능 향상)

  • Kim, Y.S.;Kim, T.H.;Park, S.H.;Choi, Y.H.;Choi, E.S.;Shin, Y.J.
    • Laser Solutions
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    • v.10 no.1
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    • pp.29-34
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    • 2007
  • We propose a novel application of laser engraving to patterning of light guide panel (LGP) for backlight. The feasibility of three-dimensional engraved pattern in the LGP was verified by measuring brightness and uniformity. To improve the overall uniformity, we have modified proposed patterns and found improved design for patterns. The tailoring of pattern by using laser engraving method could endow the controllability of uniformity. The proposed LGPs are more efficient in both average brightness and uniformity of illumination than the conventional LGPs which have surface pattern on the panel.

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Development of Sensitivity-Enhanced Detector using Pixelization of Block Scintillator with 3D Laser Engraving (3차원 레이저 각인으로 블록형 섬광체의 픽셀형화를 통한 민감도 향상 검출기 개발)

  • Lee, Seung-Jae;Baek, Cheol-Ha
    • Journal of the Korean Society of Radiology
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    • v.13 no.2
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    • pp.313-318
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    • 2019
  • To improve the sensitivity, a detector using a block scintillator was developed. In the pixelated scintillator, a reflector is located between pixels to move the light generated from the scintillator to the photosensor as much as possible, and sensitivity loss occurs in the reflector portion. In order to improve the sensitivity and to have the characteristics of the pixelated scintillator, the block scintillator was processed into a scintillator in pixel form through three-dimensional laser engraving. The energy spectra and energy resolution of each pixel were measured, and sensitivity analysis of block and pixel scintillator was performed through GATE simulation. The measured global energy resolution was 20.7%, and the sensitivity was 18.5% higher than that of the pixel scintillator. When this detector is applied to imaging devices such as gamma camera and positron emission tomography, it will be possible to shorten the imaging time and reduce the dose of patient by using less radiation source.

The Stress and Vibration Analysis of the Rotary Screen (로터리 스크린의 응력 및 진동해석)

  • Lee, Young-Shin;Choi, Myoung-Hwan;Han, You-Hie;Suh, Jung;Park, Jong-Ho
    • Journal of KSNVE
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    • v.7 no.1
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    • pp.81-89
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    • 1997
  • The structural stress and vibration analysis of the rotary screen are investigated. The mechanical properties of the rotary screen, this is, Young's modulus and density of nickel alloy are determined experimentally. The natural vibration characteristics of the rotary screen are evaluated and the displacement, the stress of the rotary screen under the various load conditions are also examined. The radial displacement of the rotary screen is obtained by experiment under various rotating speeds.

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The luminance variation of inner-scatterer light guide panel by various surface-scatterer (다양한 표면산란체에 의한 내부산란체 도광판 휘도 성능 분석)

  • Choi, Young Hee;Shin, Youngjin;Choi, Eun Seo
    • Journal of the Chosun Natural Science
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    • v.1 no.1
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    • pp.32-35
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    • 2008
  • We fabricated surface pattern on a light guide panel (LGP) using $CO_2$ laser to improve the luminescence performance of inner-scatterer LGP, which is made of PMMA sample with exploiting Q-switched $2^{nd}$ harmonic Nd:YAG laser engraving system, and the effect of surface pattern in the brightness distribution of LGP was analysed. To prove the feasibility of proposed method in the enhancement of LGP performance, we designed three different surface patterns on the inner-scatterer LGP. The experimental results has proved the potential in the application of surface pattern to increasing the brightness of inner-scatterer LGP.

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