• Title/Summary/Keyword: Haze value

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Preparation of UV Curable Anti-Glare Coating Films Using Micrometer-Sized Silica Particles (마이크로미터 크기의 실리카 입자를 이용한 UV 경화형 눈부심 방지 코팅 필름 제조)

  • Kim, Tae Hyoung;Song, Ki Chang
    • Korean Chemical Engineering Research
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    • v.59 no.2
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    • pp.165-173
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    • 2021
  • Anti-glare (AG) coating films are applied to various display fields such as liquid crystal displays, LED lighting, and touch panels. In this study, micrometer-sized silica particles were added as fillers in the UV-curable coating solutions to provide anti-glare effect. During this process, the effects of the particle size, content, stirring time, and mixing ratio of silica particles of different sizes were investigated on the haze values and visible light transmittance of the coating films. As a result, as the size of the silica particles increased and the content of the silica particles increased, the haze values increased, but the visible light transmittance decreased. On the other hand, the stirring time did not significantly affect the haze value and transmittance of coating films. In addition, as the mixing ratio of large-sized silica particles increased, the haze value increased, but on the contrary, the visible light transmittance decreased.

Improvement of haze ratio of DC-sputtered ZnO:Al thin films through HF vapor texturing

  • Kang, Junyoung;Park, Hyeongsik;Yi, Junsin
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.319.1-319.1
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    • 2016
  • Recently, the Al-doped ZnO (ZnO:Al) films are intensively used in thin film a-Si solar cell applications due to their high transmittance and good conductivity. The textured ZnO:Al films are used to enhance the light trapping in thin film solar cells. The wet etch process is used to texture ZnO:Al films by dipping in diluted acidic solutions like HCl or HF. During that process the glass substrate could be damaged by the acidic solution and it may be difficult to apply it for the inline mass production process since it has to be done outside the chamber. In this paper we report a new technique to control the surface morphology of RF-sputtered ZnO:Al films. The ZnO:Al films are textured with vaporized HF formed by the mixture of HF and H2SiO3 solution. Even though the surface of textured ZnO:Al films by vapor etching process showed smaller and sharper surface structures compared to that of the films textured by wet etching, the haze value was dramatically improved. We achieved the high haze value of 78% at the wavelength of 540 nm by increasing etching time and HF concentration. The haze value of about 58% was achieved at the wavelength of 800 nm when vapor texturing was used. The ZnO:Al film texture by HCl had haze ratio of about 9.5 % at 800 nm and less than 40 % at 540 nm. In addition to low haze ratio, the texturing by HCl was very difficult to control etching and to keep reproducibility due to its very fast etching speed.

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박막 태양전지 응용을 위하여 유리 습식 식각을 이용하여 Multi-Scale Architecture의 haze 효과

  • Oh, Donghyun;Jeon, Minhan;Kang, Jiwoon;Shim, Gyeongbae;Cho, Jaehyun;Park, Cheolmin;Kim, Hyunhoo;Yi, Junsin
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.161.1-161.1
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    • 2016
  • 박막 태양전지의 광 산란을 위한 텍스쳐 된 표면은 반사 손실을 감소시키기 위한 것이다. 그러나, 투명한 전극(TCO)의 텍스쳐 된 표면은 빛의 가용성을 제한하고, 장파장 영역에서 haze의 수치를 감소시키며, 전반사의 증가는 박막 태양전지의 Jsc를 감소시킨다. 본 논문에서는 높은 빛의 가용성을 위하여 HF+HCl 혼합용액을 이용하여 표면의 질을 향상시키기 위한 해결책을 제시했다. 같은 HF+HCl 혼합용액을 사용하여, 540 nm의 파장에서 약 85 %의 높은 haze 수치를 달성했으며, ZnO:Al 막의 증착 후에 식각된 유리 기판과 함께 비교했을 때, 2.3%의 haze 수치의 감소를 얻었다. 또, 깊은 습식 식각에 의하여 Haze 수치를 증가시키기 위한 메커니즘 간단히 설명했다. 텍스쳐 된 유리 기판의 haze 수치의 측면에서 광학 이득은 일반적인 Asahi FTO 유리(${\lambda}=540nm$의 13.5%)에 비해 상당히 높다. 이러한 높은 haze 수치의 AZO 박막은 박막 태양전지의 Jsc를 개선하는데 이용할 수 있다.

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Effective machine learning-based haze removal technique using haze-related features (안개관련 특징을 이용한 효과적인 머신러닝 기반 안개제거 기법)

  • Lee, Ju-Hee;Kang, Bong-Soon
    • Journal of IKEEE
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    • v.25 no.1
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    • pp.83-87
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    • 2021
  • In harsh environments such as fog or fine dust, the cameras' detection ability for object recognition may significantly decrease. In order to accurately obtain important information even in bad weather, fog removal algorithms are necessarily required. Research has been conducted in various ways, such as computer vision/data-based fog removal technology. In those techniques, estimating the amount of fog through the input image's depth information is an important procedure. In this paper, a linear model is presented under the assumption that the image dark channel dictionary, saturation ∗ value, and sharpness characteristics are linearly related to depth information. The proposed method of haze removal through a linear model shows the superiority of algorithm performance in quantitative numerical evaluation.

Novel Deposition Technique of ZnO:Al Transparent Conduction Oxide Layer on Chemically Etched Glass Substrates for High-haze Textured Surface

  • Park, Hyeongsik;Pak, Jeong-Hyeok;Shin, Myunghoon;Bong, Sungjae;Yi, Junsin
    • Proceedings of the Korean Vacuum Society Conference
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    • 2014.02a
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    • pp.426.1-426.1
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    • 2014
  • For high performance thin film solar cells, texturing surface, enhancing the optical absorptionpath, is pretty important. Textured ZnO:Al transparent oxide layer of high haze is commonly used in Si thin film solar cells. In this paper, novel deposition method for aluminum doped zinc oxide (ZnO:Al) on glass substrates is presented to improve the haze property. The broccoli structure of ZnO:Al layer was formed on chemically etched glass substrates, which showed high haze value on a wide wavelength range.The etching condition of the glass substrates can change not only the haze values of the ZnO:Al of in-situ growth but alsothe electrical and optical properties of the deposited ZnO:Al films.The etching mechanism of the glass substrate affecting on the surface morphology of the glass will be discussed, which resulted in variation of texture of ZnO:Al layer. The optical properties of substrate morphology were also analyzed with EDS and FTIR results. As a result, the high haze value of 85.4% was obtained in the wavelength range of 300 nm to 1100 nm. Furthermore, low sheet resistance of about 5~18 ohm/sq was achieved for different surface morphologies of the ZnO:Al films.

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Surface Morphology and Optical Properties of Aluminosilicate Glass Manufactured by Physical and Chemical Etching Process (물리·화학적 혼합 식각 공정에 의해 제조된 알루미노실리케이트 유리의 표면 형상과 광학 특성)

  • Kim, Namhyuk;Sohn, Jeongil;Kim, Gwangsoo
    • Korean Journal of Materials Research
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    • v.27 no.9
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    • pp.501-506
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    • 2017
  • Surface morphology and optical properties such as transmittance and haze effect of glass etched by physical and chemical etching processes were investigated. The physical etching process was carried out by pen type sandblasting process with $15{\sim}20{\mu}m$ dia. of $Al_2O_3$ media; the chemical etching process was conducted using HF-based mixed etchant. Sandblasting was performed in terms of variables such as the distance of 8 cm between the gun nozzle and the glass substrate, the fixed air pressure of 0.5bar, and the constant speed control of the specimen stage. The chemical etching process was conducted with mixed etching solution prepared by combination of BHF (Buffered Hydrofluoric Acid), HCl, and distilled water. The morphology of the glass surface after sandblasting process displayed sharp collision vestiges with nonuniform shapes that could initiate fractures. The haze values of the sandblasted glass were quantitatively acceptable. However, based on visual observation, the desirable Anti-Glare effect was not achieved. On the other hand, irregularly shaped and sharp vestiges transformed into enlarged and smooth micro-spherical craters with the subsequent chemical etching process. The curvature of the spherical crater increased distinctly by 60 minutes and decreased gradually with increasing etching time. Further, the spherical craters with reduced curvature were uniformly distributed over the etched glass surface. The haze value increased sharply up to 55 % and the transmittance decreased by 90 % at 60 minutes of etching time. The ideal haze value range of 3~7 % and transmittance value range of above 90 % were achieved in the period of 240 to 720 minutes of etching time for the selected concentration of the chemical etchant.

The Synthesis and Characterization of Thin Film for Anti-Glare Using Silica Particles (실리카 입자를 이용한 눈부심 방지용 박막의 제조 및 특성)

  • Ahn, Jae-Beom;Noh, Si-Tae
    • Applied Chemistry for Engineering
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    • v.19 no.6
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    • pp.685-689
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    • 2008
  • The effect of filler type and dispersion time on thin film characterization is studied. Hollow silica powders which have the advantage of transmittance are selected. In this paper, the characterization of haze, transmittance, and gloss are analyzed in terms of filler concentration and coating thickness, respectively. As a result, the value of haze and gloss increased with increasing of filler concentration and coating thickness, respectively. In addition, the variation of transmittance by filler concentration and coating thickness is not occurred. In conclusion, it is assumed that hollow silica powders as a filler have an advantage of concentration increment and transmittance.

Analysis of Color Distortion in Hazy Images (안개가 포함된 영상에서의 색 왜곡 특성 분석)

  • JeongYeop Kim
    • Journal of Platform Technology
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    • v.11 no.6
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    • pp.68-78
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    • 2023
  • In this paper, the color distortion in images with haze would be analyzed. When haze is included in the scene, the color signal reflected in the scene is accompanied by color distortion due to the influence of transmittance according to the haze component. When the influence of haze is excluded by a conventional de-hazing method, the distortion of color tends to not be sufficiently resolved. Khoury et al. used the dark channel priority technique, a haze model mentioned in many studies, to determine the degree of color distortion. However, only the tendency of distortion such as color error values was confirmed, and specific color distortion analysis was not performed. This paper analyzes the characteristic of color distortion and proposes a restoration method that can reduce color distortion. Input images of databases used by Khoury et al. include Macbeth color checker, a standard color tool. Using Macbeth color checker's color values, color distortion according to changes in haze concentration was analyzed, and a new color distortion model was proposed through modeling. The proposed method is to obtain a mapping function using the change in chromaticity by step according to the change in haze concentration and the color of the ground truth. Since the form of color distortion varies from step to step in proportion to the haze concentration, it is necessary to obtain an integrated thought function that operates stably at all stages. In this paper, the improvement of color distortion through the proposed method was estimated based on the value of angular error, and it was verified that there was an improvement effect of about 15% compared to the conventional method.

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Estimation of the Medium Transmission Using Graph-based Image Segmentation and Visibility Restoration (그래프 기반 영역 분할 방법을 이용한 매체 전달량 계산과 가시성 복원)

  • Kim, Sang-Kyoon;Park, Jong-Hyun;Park, Soon-Young
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.4
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    • pp.163-170
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    • 2013
  • In general, images of outdoor scenes often contain degradation due to dust, water drop, haze, fog, smoke and so on, as a result they cause the contrast reduction and color fading. Haze removal is not easier problem due to the inherent ambiguity between the haze and the underlying scene. So, we propose a novel method to solve single scene dehazing problem using the region segmentation based on graph algorithm that has used a gradient value as a cost function. We segment the scene into different regions according to depth-related information and then estimate the global atmospheric light. The medium transmission can be directly estimated by the threshold function of graph-based segmentation algorithm. After estimating the medium transmission, we can restore the haze-free scene. We evaluated the degree of the visibility restoration between the proposed method and the existing methods by calculating the gradient of the edge between the restored scene and the original scene. Results on a variety of outdoor haze scene demonstrated the powerful haze removal and enhanced image quality of the proposed method.