• Title/Summary/Keyword: single lens

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Effects of Myopia Alleviation Lenses in accordance with Parents' Refractive Errors (부모의 굴절이상에 따른 근시완화렌즈 효과)

  • Cho, Yoon Chul;Kang, JoongGu;Leem, Hyun Sung
    • The Korean Journal of Vision Science
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    • v.20 no.4
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    • pp.569-577
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    • 2018
  • Purpose : The study looked at how effective each group wearing MyoVison lens, MC lens, and Single Vision lensdepending on their parents' myopia condition. Methods : The study observed the changeof spherical equivalent among customers, who visited between January 2010 and December 2016,of an optical shop in Incheon Metropolitan City. And we observed MyoVision 152 eyes, MC Lens 86 eyes and Single Vision lens 270 eyes. This study was conducted using SPSS ver18, which analyzes the changes in average values of MyoVision, MC Lens, and Single Vision for a year.In each group, the differences in the group were compared using the Paired T-test and then one-way ANOVA (post-hoc; Bonferroni) Results : Group-to-group comparisons showed that MyoVision and MC Lens have a shorterinhibition than Single Vision. In particular, MyoVisionand MC Lens showed different relief effects depending on the degree of refraction of parents.When both parents had normal refractive, the change between MyoVision and Single Vision lens was $-0.35{\pm}0.05D$. When the father had a refraction MC lens were $-0.36{\pm}0.14D$ more effective than Single Vision. When only the mother had refraction, the mean value between MyoVision and Single Vision lens was $-0.37{\pm}0.06D$, and the mean between MC lens and Single Vision lens was $-0.38{\pm}0.08D$. And when both parents had refraction problems, the mean value change between MyoVision and Single Vision lens was $-0.28{\pm}0.07D$, and $-0.31{\pm}0.07D$, respectively. Conclusion : MyoVision and MC Lens appeared to have no effect on the functions of mitigating myopia in within group comparisons, but MyoVision and MC Lens showed reducing myopia than Single Vision in between group.

New single lens stereoscopic camera system for UHD 3D applications (UHD 3D응용을 위한 새로운 single lens stereoscopic camera system 제안)

  • Park, Sangil;Yoo, Sunggeun;Lee, Younghwa;Lee, Taehwan
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2013.11a
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    • pp.124-127
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    • 2013
  • 2009년 출시된 영화 "AVATAR"가 stereoscopic방식 3D영화로 대단한 성공을 거둔 이후로 가전시장과 필름 시장에는 많은 3D 영상들이 stereoscopic방식으로 제작되어 유통되게 되었다. 하지만 기존에 제시되어온 two lens stereoscopic camera system은 두 대의 카메라를 사용하기 때문에 광학적 정렬과 기하학적 조절이 매우 어렵기 때문에 stereoscopic 영상을 촬영하고 보급 하는데 많은 문제점을 가지고 있었다. 따라서 하나의 광축을 가진 single lens stereoscopic camera system들이 기존에 제시되어 왔으나 여전히 single lens stereoscopic system에도 문제점이 존재한다. 이에 본 논문에서는 기존에 제시된 stereoscopic camera system을 two lens / single lens로 나누어 조사 분석하고, 분석한 문제점을 해결하기 위한 새로운 single lens stereoscopic camera system을 제안할 것이다.

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Design of micro lens array (Micro lens array 설계)

  • 홍경희
    • Korean Journal of Optics and Photonics
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    • v.5 no.2
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    • pp.204-211
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    • 1994
  • Micro array lens systems are designed for a faximile or copy machine. The array type is hexagonal. Diameter of a lens is 0.16 mm and the distance of the center of the nearest neighbor is 0.192 mm. The magnitude of the lens system is 1:1. Working distane is 10.55 mm and the spot size is less than 0.04 mm radius on axis and 0.20 mm off-axis in case of single layer system. Working distance is 7.90 mm and the spot size is less than 0.07 mm radius on axis and 0.09 mm radius off axis in case of double layer system. Performance of single layer micro array lens system and double layer micro array lens system are compared with the characteristics of the ray fans.y fans.

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Design and Verification of Hybrid Optical System for LED Surgical Light

  • Kwon, Young-Hoon;Ahn, Sun-Su;Lee, Seung-Jin;Kwon, Ki-Jin
    • Journal of the Optical Society of Korea
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    • v.19 no.4
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    • pp.421-426
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    • 2015
  • This paper presents a hybrid single optical system for an LED surgical light that combines the advantages of both lens- and reflector-type single optical systems. The proposed hybrid single optical system includes a lens in the center and the LED light originating from the lens is redirected using a reflector to achieve a high beam spread. Iterative optical software simulations are used to provide data for the design of the lens and reflector for a single optical system, and for a complex optical system for the LED light assembly. The resulting data is also used to fabricate a prototype system. Experiments using the prototype of the hybrid single optical system and a mock-up LED surgical light confirm the system's shadow dilution performance and its applicability to surgical operations.

Continuous-phase Lens Design via Binary Dielectric Annular Nanoslits

  • Woongbu Na;Seung-Yeol Lee;Hyuntai Kim
    • Current Optics and Photonics
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    • v.7 no.3
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    • pp.304-309
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    • 2023
  • In this study, a binary dielectric annular nanoring lens is proposed to cover the full range of optical phase. The lens is designed numerically, based on the effective-medium theory. The performance of the proposed lens is verified for the cases of single-focal and dual-focal lenses. The efficiency of a single-focal lens is improved by 17.19% compared to a binary dielectric lens, and that of a dual-focal lens shows enhancements of 13.11% and 49.41% at the two focal points. This lens design can be applied to other optical components with axially symmetric structures.

linical Performance Analysis of Lens for Improving VDT Syndrome (VDT 증후군 개선을 위한 렌즈의 임상성능 분석)

  • Ryu, Geun-Chang;Park, Ji-Hoon;Jun, Jin;Jin Moon-Seog;Chae, Soo-Chul
    • Journal of Korean Ophthalmic Optics Society
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    • v.14 no.4
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    • pp.45-51
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    • 2009
  • Purpose: The purpose of this study is to compare and analyze the survey results of clinical performance and visual problem, and the survey were carried out before and after of VDT working for 4 hours by wearing functional lens designed for improving VDT syndrome and single-vision lens. Methods: We tested near & far visual acuity, change of spherical equivalent, near point of accommodation, near point of convergence, AC/A ratio, accommodative facility and survey of subjective symptoms to visual problem of before and after VDT working for 4 hours after wearing single-vision lens and functional lens subjected on 30 males and females in the age of 20 to 45. Results: When wearing functional lens comparing to single-vision lens, near visual acuity, near point of accommodation, near point of convergence, and accommodative facility are significantly improved. It is investigated that average scores of 10 items to visual problem after VDT working for 4 hours are 3.63${\pm}$0.75 at single-vision lens and 4.69 ${\pm}$ 0.83 at functional lens, and therefore functional lens is significantly improved. Conclusions: It is thought that functional lens is an excellent lens which helps to improve accommodative function and visual problem after VDT working for 4 hours than single-vision lens.

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Changes of Refractive Correction Value with Different Age Group: A Case for Myopia Control Lens, Single Vision Lens and Reverse Geometry Contact Lens (Myopia Control Lens, Single Vision Lens, Reverse Geometry Contact Lens의 연령에 따른 굴절교정상태 변화에 대한 추적 연구)

  • Yoon, Min-Hwa
    • Journal of Korean Ophthalmic Optics Society
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    • v.18 no.1
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    • pp.75-84
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    • 2013
  • Purpose: Changes of refractive correction value in different age group were investigated. Regarding the inhibitive effects against myopia progression after wearing reverse geometry contact lenses and myopia control lenses (MC lenses), the effects after wearing single vision lenses were compared. Methods: We organized children between the ages of six and fifteen into three groups by age, and distributed fifty-seven reverse geometry contact lenses, fifty-six MC lenses and seventy-eight single vision lenses among them to be worn. Group 1 consisted of children aged ten and under, Group 2 consisted of children between the ages of eleven and fifteen, and Group 3 represents all of the study participants. The aim of this study was to learn the inhibitive effects against myopia progression attained by changes of refractive correction value and to verify their statistical significance at twelve months and under, thirteen to twenty-four months and twenty-five to thirty-six months. Results: Changes of refractive correction value by each length of use in Group 3 were as follows. For the age group of under twelve months, participants using the reverse geometric contact lens showed no change, while those using the MC or single vision lens had significant changes (P<0.05) of $-0.36{\pm}0.10$ D and $-0.67{\pm}0.52$ D, respectively. Users of all three lens types displayed significant change (P<0.05), in the age group of between thirteen and twenty-four months, of $0.18{\pm}0.49$ D, $0.60{\pm}0.42$ D and $1.37{\pm}0.72$ D for users of the reverse geometry contact lens, the MC lens and the single vision lens, respectively. There were significant changes (P<0.05) of $0.29{\pm}0.61$ D, $0.93{\pm}0.57$ D and $1.72{\pm}0.78$ in the same respective order as the above in the age group of twenty-five to thirty-six months. Refractive correction value showed changes with different age group. Group 1 displayed significant changes (P<0.05) of $0.29{\pm}0.73$ D, $1.07{\pm}0.59$ D and $1.75{\pm}0.74$ D for users of the reverse geometry contact lens, MC lens and single vision lens, respectively, up to thirty-six months of lens wearing; Group 2, also up to thirty-six months, displayed significant changes (P<0.05) of $0.28{\pm}0.42$ D, $0.75{\pm}0.49$ D and $1.70{\pm}0.84$ D in the same respective order, and changes in refractive correction for the age group under ten years was significantly greater (P<0.05) for the age group of eleven and older. Conclusions: The results found in this study demonstrate that there were no changes of refractive correction value for the case of wearing reversing geometry contact lens up to twelve month or less. MC lens showed less changes in variations of visual acuity for all users which might be resulted in inhibiting progression of myoptia. When both reverse geometry contact lens and the MC lens are wearing for the period from 13 to 36 month, both lens showed less changes in variation of visual acuity for all users. The results suggested that the less changes in variation of visual acuity of both lens had an effect on inhibiting progression of myopia.

The comparison and the Analysis of the optical performances between the single and the symmetrical double DOE lenses (단매와 대칭 2매로 구성된 DOE 렌즈의 광학성능 비교 및 분석)

  • 이환선;임천석;조재홍
    • Korean Journal of Optics and Photonics
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    • v.13 no.3
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    • pp.258-265
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    • 2002
  • In this paper, we design single and symmetrical double lenses with DOE. The specifications are the following : Image area is 4.8 mm $\times$ 3.6 mm, F/# is 2.8 and the overall length (from first lens surface to image plane) is 6.8mm. After comparing the optical performance and characteristic values, we determine that symmetrical double lenses are superior to single lenses. Symmetrical double lenses have the merits of fewer zones, weaker flare, and smaller distortion than single lenses.

DERIVATION OF THE GRAVITATIONAL MULTI-LENS EQUATION FROM THE LINEAR APPROXIMATION OF EINSTEIN FIELD EQUATION

  • KANG SANGJUN
    • Journal of The Korean Astronomical Society
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    • v.36 no.3
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    • pp.75-80
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    • 2003
  • When a bright astronomical object (source) is gravitationally lensed by a foreground mass (lens), its image appears to be located at different positions. The lens equation describes the relations between the locations of the lens, source, and images. The lens equation used for the description of the lensing behavior caused by a lens system composed of multiple masses has a form with a linear combination of the individual single lens equations. In this paper, we examine the validity of the linear nature of the multi-lens equation based on the general relativistic point of view.