• Title/Summary/Keyword: IR-cut off

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The analysis of the Effect the Minute Quantities of Infrared Rays that Were not Filtered by IR Cut-Off Filter has on Digital Images (IR Cut-Off Filter가 차단하지 못한 미량의 적외선이 디지털화상에 미치는 영향 분석)

  • Lee, Yong-Hwan;Park, Se-Won;Hong, Jung-Eui
    • The Journal of the Korea Contents Association
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    • v.11 no.5
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    • pp.205-215
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    • 2011
  • Films are sensitive to ultraviolet rays and in contrast, digital camera sensors are extremely sensitive to infrared rays due to the differences in spectral characteristics. As a result, all digital cameras that use CCD or CMOS are equipped with IR Cut-Off Filter on the overall sensor. Complete block out of infrared rays is ideal, but the actual experiment results showed that infrared rays were not being blocked out completely. Infrared permeability was also different for each camera. Therefore, this study aims to analyze the effect of the minute quantities of infrared rays, which get transmitted due to mechanical properties of IR Cut-Off Filters that are installed on digital cameras, on digital picture images. The results obtained by carrying out a comparative analysis of a UV Filter (infrared transmitting state) and a UV-IR Filter (infrared blocked out state) are as follows. It was confirmed that the minute quantities of infrared rays do affect dynamic range and resolution to some extent, despite the little or no difference in noise and color reproduction.

IR Cut-off Filter Made of CeO2 and SiO2 Thin Films Coated on PMMA Substrate (PMMA 기판에 CeO2와 SiO2를 코팅하여 제작한 적외선 차단필터)

  • Yu, Yeon-Serk;Choi, Sang-Serk
    • Korean Journal of Optics and Photonics
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    • v.17 no.5
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    • pp.480-486
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    • 2006
  • Generally, IR cut-off filters for mobile phone is coated on the glass substrate at high temperature(above $300^{\circ}C$). In this work, we prepared IR cut-off filters on the poly(methyl methacrylate)(PMMA) substrates at low temperature(about $70^{\circ}C$ ). using the $CeO_2\;and\;SiO_2$ coatings by physical vapor deposition. The surface energies of coated and uncoated PMMA, and adhesive properties of IR cut-off filters coatings were examined using contact angle measurements. We demonstrate the improve of mobile phone optical system using these results.

An Ultra-thin IR Cut-off Filter Based on Nanostructures (나노구조 기반 초박형 적외선 차단 필터)

  • Hyundo Yang;Jong-Kwon Lee
    • Korean Journal of Optics and Photonics
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    • v.35 no.1
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    • pp.24-29
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    • 2024
  • We propose a hyperbolic metastructure based on a nanopatterned metal (Ag)-dielectric (PDMS) multilayer and report on its performance in an infrared (IR) cut-off filter for imaging devices. By optimizing the size of the square-shaped Ag nanopattern and the thickness of PDMS surrounding the Ag nanopattern, the proposed IR cut-off filter blocks 99% of light in the 0.70-1.01 ㎛ wavelength band while maintaining a high transmittance of over 94% in the visible region. Here, the cut-off wavelength band starts at a region above the epsilon-near-zero wavelength of the hyperbolic metastructure and ends at the point where plasmonic absorption appears strongly. It is observed that transmittance in the wavelength region longer than the IR cut-off band increases again due to plasmonic coupling among horizontally adjacent Ag nanopatterns. This metastructure can improve the performance of IR-blocking filters as well as allow it to be manufactured ultra-thin, which is applicable to various planar optical elements and integrated optical components.

An Experimental Analysis on Dark-field Laser Scattering for the Surface Inspection of Infrared Cut-off Filters (적외선차단필터의 표면 검사를 위한 암시야 레이저산란에 대한 실험적 분석)

  • Kim, Gyung-Bum;Han, Jae-Chul
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.11
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    • pp.76-83
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    • 2007
  • The dark-field laser scattering system has been developed to inspect surface defects in infrared cut-off filters and then laser scattering characteristics against the defects are investigated. The qualitative analysis for the reliable and accurate detection performance is described through the correlation between incident angles of a laser and viewing ones of a camera. In this paper, reliable and important information with laser scattering is given for the surface defect inspection of IR filters. Its performance has been verified through various experiments.

Different Criteria for the Definition of Insulin Resistance and Its Relation with Dyslipidemia in Overweight and Obese Children and Adolescents

  • Nogueira-de-Almeida, Carlos Alberto;de Mello, Elza Daniel
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.21 no.1
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    • pp.59-67
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    • 2018
  • Purpose: to compare cut off points corrected for age and gender (COOP) with fixed cut off points (FCOP) for fasting plasma insulin and Homeostatic model assessment-insulin resistance (HOMA-IR) for the diagnosis of IR in obese children and adolescents and their correlation with dyslipidemia. Methods: A multicenter, cross-sectional study including 383 subjects aged 7 to 18 years, evaluating fasting blood glucose, plasma insulin, and lipid profile. Subjects with high insulin levels and/or HOMA-IR were considered as having IR, based on two defining criteria: FCOP or CCOP. The frequency of metabolic abnormalities, the presence of IR, and the presence of dyslipidemia in relation to FCOP or CCOP were analyzed using Fisher and Mann-Whitney exact tests. Results: Using HOMA-IR, IR was diagnosed in 155 (40.5%) and 215 (56.1%) patients and, using fasting insulin, 150 (39.2%) and 221 (57.7%), respectively applying FCOP and CCOP. The use of CCOP resulted in lower insulin and HOMA-IR values than FCOP. Dyslipidemia was not related to FCOP or CCOP. Blood glucose remained within normal limits in all patients with IR. There was no difference in the frequency of IR identified by plasma insulin or HOMA-IR, both for FCOP and CCOP. Conclusion: The CCOP of plasma insulin or of HOMA-IR detected more cases of IR as compared to the FCOP, but were not associated with the frequency of dyslipidemia. As blood glucose has almost no fluctuation in this age group, even in the presence of IR, fasting plasma insulin detected the same cases of IR that would be detected by HOMA-IR.

650nm IR Cut-off 필터의 제작 및 특성

  • Sin, Gwang-Su;Kim, Jin-Hyeok;Gi, Hyeon-Cheol;Kim, Hyo-Jin;Go, Hang-Ju;Kim, Seon-Hun;Kim, Du-Geun;Han, Myeong-Su
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.169-169
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    • 2010
  • 650nm 적외선 차단 필터를 Macleod 프로그램을 이용하여 설계하고, 이온보조증착(IAD) 장비를 이용하여 코팅한 후 투과도, 파장, 두께특성을 조사하였다. 차단필터의 증착물질은 $TiO_2$ (n=2.30) /$SiO_2$ (n=1.46) 을 사용하여 45층의 다층 박막으로 증착하였다. 코팅된 차단필터는 차단파장이 651 nm로써 평균 ${\pm}5$ nm 이내의 편차를 보였다. 420~630 nm 파장영역에서 평균 투과도는 89%이었으며, 투과도의 균일도는 약 2.12로써 매우 균일하였다. 투과도기 단파장 영역에서 감소된 것은 다층박막 증착 시 산소가 결핍된 것으로 판단된다.

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Properties of glass fiber by adding $Ga_2O_3$ in the $SiO_2-PbO-K_2O-Al_2O_ 3$ system for infrared sensor ($Ga_2O_3$ 첨가에 따른 $SiO_2-PbO-K_2O-Al_2O_ 3$계 적외선 센서용 glass fiber의 특성)

  • 이명원;윤상하;강원호
    • Electrical & Electronic Materials
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    • v.9 no.10
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    • pp.1047-1052
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    • 1996
  • In this study, the thermal and optical proper-ties of multicomponent oxide glass fiber for IR sensor by adding heavy metal oxide Ga$_{2}$O$_{3}$ were investigated. The fiber samples were made by rod-in tube method. The optical loss of fiber was measured in 0.3-1.8/M wavelength region. As Ga$_{2}$O$_{3}$ increased up to 12wt%, the transition and softening temperature of bulk glass were increased from 495.deg. C to 564.deg. C and from 548.deg. C to 612.deg. C respectively. Whereas the thermal expansion coefficient was decreased from 102 to 88.2*10$^{-7}$ /.deg. C. The refractive index was increased from 1.621 to 1.662, and IR cut-off wavelength was enlarged from 4.64.mu.m to 5.22.mu.m. The optical loss of fiber was decreased and more remarkably decreased in 1.146.mu.m-1.8.mu.m wavelength region.

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Fabrication of ATO thin film for IR-cut off by sol-gel method (솔-젤 법에 의한 적외선 차단 ATO 박막 제조)

  • Kim, Jin-Ho;Lee, Kwang-Hee;Lee, Mi-Jai;Hwang, Jonghee;Lim, Tae-Young
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.23 no.5
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    • pp.230-234
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    • 2013
  • IR cut-off thin films consisted of ATO nanoparticles were successfully fabricated by sol-gel method. The coating solution was synthesized with organic/inorganic hybrid binder and ATO colloidal solution and ATO thin films were coated on a slide glass with the withdrawal speed of 5~40 mm/s. As the withdrawal speed increased from 5 mm/s to 40 mm/s, the thickness of coating thin films also increased from $1.05{\mu}m$ to $4.25{\mu}m$ and the IR cut-off in wavelength of 780~2500 nm increased from 49.5 % to 66.7 %. In addition, the pencil hardness of ATO thin films dried at $80^{\circ}C$ was ca. 5H and the coating films were not removed after a cross cutter tape test because of the hybrid binder synthesized with tetraethylorthosilicate and methyltrimethoxysilane. The surface morphologies, optical properties and film thickness of prepared thin films with a different withdrawal speed were measured by field emission scanning electron microscope (FE-SEM), UV-Vis spectrophotometer, and Dektak.

Localization System for Mobile Robot Using Electric Compass and Tracking IR Light Source (전자 나침반과 적외선 광원 추적을 이용한 이동로봇용 위치 인식 시스템)

  • Son, Chang-Woo;Lee, Seung-Heui;Lee, Min-Cheol
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.8
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    • pp.767-773
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    • 2008
  • This paper presents a localization system based on the use of electric compass and tracking IR light source. Digital RGB(Red, Green, Blue)signal of digital CMOS Camera is sent to CPLD which converts the color image to binary image at 30 frames per second. CMOS camera has IR filter and UV filter in front of CMOS cell. The filters cut off above 720nm light source. Binary output data of CPLD is sent to DSP that rapidly tracks the IR light source by moving Camera tilt DC motor. At a robot toward north, electric compass signals and IR light source angles which are used for calculating the data of the location system. Because geomagnetic field is linear in local position, this location system is possible. Finally, it is shown that position error is within ${\pm}1.3cm$ in this system.