• Korean Journal of Optics and Photonics
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• v.9 no.5
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• pp.291-299
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• 1998

In the rear projection TV, the optimal system configurations of optical parts are presented, which are focused on competitive price and performances. From the initial design with five Seidel aberrations free, aspherization of the plastic lenses, and optimization with tolerances, a new lens consisting of two plastic and one glass lenses was designed. It is able to be used on current broadcast standard NTSC and digital TV in common. The developed CRT-lens assembly could display the 40 to 50 inch image and its resolution is more than 800 TV-lines.

• The Optical Journal
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• s.100
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• pp.62-64
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• 2005

Projector의 소형화·경량화·저가격화가 진행됨에 따라 개인의 구입이 증가하고, 비즈니스용도와는 다른 시장이 확대되고 있는 것이 최근 경향이다. 또한 고정밀 TV로서 큰 주목을 받고 있으며 Projector의 주요 부품인 투사 렌즈의 역할은 점점 중요해지고 있다는 것은 분명하다. 투사 렌즈는 지난 10년 사이에 광학의 기본은 유지해오면서 큰 진보를 이루었지만, 점점 복잡해지는 시장 요구에 따르기 위하여 새로운 광학계의 개발이나 몇 가지 괄목할만한 발전이 이루어지지 않으면 안 된다. 이를 위해서는 광학의 기본으로 돌아가서 광학계를 재검토하는 것과 계속적으로 기술을 추구하는 것이 중요하다

• Korean Journal of Optics and Photonics
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• v.24 no.5
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• pp.224-230
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• 2013

Laser Lift-Off (LLO) is a process that removes a GaN or AIN thin layer from a sapphire wafer to manufacture vertical-type LEDs. It consists of a light source, an attenuator, a mask, a projection lens and a beam homogenizer. In this paper, we design an attenuator and a projection lens. We use the 'ZEMAX' optical design software for analysis of depth of focus and for a projection lens design which makes $7{\times}7mm^2$ beam size by projecting a beam on a wafer. Using the 'LightTools' lighting design software, we analyze the size and uniformity of the beam projected by the projection lens on the wafer. The performance analysis found that the size of the square-shaped beam is $6.97{\times}6.96mm^2$, with 91.8 % uniformity and ${\pm}30{\mu}m$ focus depth. In addition, this study performs dielectric coating using the 'Essential Macleod' to increase the transmittance of an attenuator. As a result, for 23 layers of thin films, the transmittance total has 10-96% at angle of incidence $45-60^{\circ}$ in S-polarization.

• Applied Microscopy
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• v.35 no.4
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• pp.98-104
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• 2005

A FOV (field-of-view) of the HV-MSC (high voltage multi-scan CCD, $1024{\times}1024$ pixels) camera mounted in the post-column HV-GIF (high voltage gatan image filter) has been drastically enlarged by the projection lens current adjustment. An imaging area of the HV-MSC camera obtained at the lowest magnification (2,000x) is $112{\mu}m^2$ which corresponds to the recording area of the film at the magnification of 8,800x, while the achievable recording area is only $0.43{\mu}m^2$ at the same magnification without this technique. Ignoring the image distortion of less than 5%, we have designed an on-site reference graph to estimate projection lens currents for microscope magnifications above 8,800x, where the recording area on the HVMSC is same as that on the film.

• Korean Journal of Optics and Photonics
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• v.4 no.2
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• pp.145-156
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• 1993

From the optimal system specifications of optical parts in rear projection TV focused on competitive price and performances, we designed and developed projection lens which is able to be used on current broadcast standard NTSC and HDTV in common. Through the serial processes, which are initial design of all aberrations free, aspherization of the plastic lenses, optimization with tolerances and manufacturability, and athermalization, the lens was designed. The developed CRT-lens ass'y could display the 40-55 inches image and it's resolution is more than 1000 TV-lines.

• 한국전자현미경학회:학술대회논문집
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• 2004.11a
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• pp.139-144
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• 2004

• Korean Journal of Optics and Photonics
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• v.9 no.6
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• pp.368-372
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• 1998

A 16-views 3 dimensional imaging system is designed by spatially combinding two 8-views time multiplexed image channels. Each 8-views channel composed of 3 primary color CRTs and a dichroic beam splitter which combining the three CRTs as one channel. Each CRT displays 8-view images time sequentially. These images are projected to a holographic screen of a size 1$\times$0.8 $m^2$ through a projection optics. Characteristics of the three different configurations of projection optics are examined with the optics designing program "DEMOS" to select an optimized projection optics for the system. The configulation of the optimized projection optics is found like following; images from each channel combined by two-fold mirror are projected by a projection objective through a 16-strips LCD shutter. In this configuration, the shutter should be located at the entrance pupil of the objective, and the folded edge of the two-fold mirror should contact symmetrically to the center line of the shutter.e shutter.

• Proceedings of the Optical Society of Korea Conference
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• 2004.07a
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• pp.74-75
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• 2004

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.198-199
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• 2001

본 논문은 스테레오 영상의 왜곡 현상을 분석하는 수학적인 해석 방법을 제안하였다. 스테레오 카메라의 중심과 투사기의 중심을 연결하는 직선이 스크린이 가지는 평면의 중심을 지나는 법선 벡터가 되고, 스테레오 카메라와 투사기의 두 렌즈의 광축이 스크린의 중심에 놓일 경우에 사진을 찍는 조건, 투영 조건 및 관측 조건에 해당하는 해석해를 유도하였다. 위 세 가지 조건에 따라 영상의 왜곡 정도가 바뀌게 되는데 왜곡을 최소한으로 만들 수 있는 조건식을 유도하였다.

• Journal of the Korean Society for Precision Engineering
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• v.14 no.3
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• pp.28-34
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• 1997

The side burrs and shape distortion resulting from the micromachining of an array of V-shape microgrooves in fresnel lens mould were experimentally invesigated. The focus of this study is on the influence of depth of cut and prism angle on the burr growing rate. The main experiments were con- ducted on the single prism cutting for the convinient of measuring the burr shape and cutting force. From the observation of the burr shape and burr growing rate, it was found that there exits a critical depth of cut below which the burrs are more or less irregular and weak. But above that critical value, the burrs are re- latively clear and stiff.