• 반도체디스플레이기술학회지
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• 제20권1호
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• pp.77-82
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• 2021

Using a multi-array needle module developed for coating of high-density cylindrical microlens array (C-MLA), we have fabricated an anti-Moiré filter for LED screens. The Moiré phenomenon appears due to the interference between the array pattern of image sensors in a camera and the non-emission area (grid pattern) of a LED screen. To suppress it, we have employed poly(methyl methacrylate) (PMMA) and coated it on a glass substrate in the form of a grid and non-grid (parallel lines). We have rotated the needle module in order to increase the number of C-MLAs. With this scheme, we have fabricated the 150 mm × 150 mm anti-Moiré filters where 836 microlens lines are formed. They show the average width of 255.4 ㎛, the average distance between CMLs of 94.6 ㎛, and C-MLA width non-uniformity of 4.7%. We have shown that the Moiré patterns still appear in the presence of the parallel (non-grid)-type filter, whereas they disappeared completely by the grid-type filter. It is due to the fact that the Moiré patterns are diffused more effectively by the grid-type C-MLA.

• 한국광학회지
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• 제24권5호
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• pp.231-236
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• 2013

본 논문에서는 멀티 어레이 엘이디를 이용한 불연속적인 광원의 빔 패턴이 광학계만으로 연속적인 매트릭스 빔으로 형성되어 광원의 점 소등만으로 다양한 빔 패턴을 구현할 수 있는 지능형 전조등의 광학 설계를 연구하였다. 기존 지능형 전조등의 기술과 다르게 멀티 어레이 엘이디를 이용한 지능형 전조등은 다수의 광원 엘이디와 하나의 광학계 어셈블리 모듈 구성으로 전자 제어를 통해 별도의 기구적인 작동 없이 빔 패턴을 변화시킬 수 있다. 본 연구에서 광학 설계는 상향등과 자동 조정 주행등의 패턴 구현과 광도 값을 만족시키기 위해 LED 앞 단에 2차렌즈 설계와 측벽 설계, 투사렌즈 설계를 실시하였다. 그 결과 불연속적인 광원의 패턴이 광학계를 통해 전방 25 m에서 14개의 동일한 사이즈와 밝기를 갖는 셀들이 모여 연속적인 하나의 매트릭스 빔 패턴을 형성하는 설계 조건을 만족하였다. 또한 설계된 광학계의 제작 및 측정을 통해 상향등의 원거리 시인성을 위한 최대 45000 cd 이상의 배광 법규 조건을 약 50000 cd로 만족하였고, 자동 조정 주행 빔 패턴 구현 시 광원의 소등 영역이 0.32 lx로 측정되어 배광 법규 0.4 lx 이하를 만족하였다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.882-884
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• 2005

A new rectangular shape microlens array having high sag for solid-state lighting is presented. Proposed microlens, which has high sag, over $375{\mu}m$ and large diameter, over 3 mm can enormously enhance output optical extraction efficiency. Rectangular shape of microlens can maximize the fill factor of light-emitting-diode (LED) package and minimize the optical loss at the same time. This wafer level microlens array is fabricated on LED package. It has many advantages in optical properties, low cost, high aligning accuracy, and mass production.

• 한국공작기계학회논문집
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• 제16권3호
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• pp.50-55
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• 2007

The purpose of this research is to enhance the luminance of the LED and to improve the implementation of color by mounting an array lens on the LED without special technology in process. The workmanship of key components considering the economical efficiency and the injection molding technology for high quality of the product are essential to achieve it. In this paper, the mold was computer-aided was designed and manufactured by CAM software (NX4) and high speed machining center. the applied final machining conditions were 3,000-5,000mm/min feed speed, 15,000-25,000rpm and ${\Phi}0.3mm$ ball end-mill. And the Flow analysis was performed using the mold flow software(MPI) in order to get uniformity of resin. Injection conditions acquired by the flow analysis and the injection experiment are as follows. The cylinder temperature is $220-260^{\circ}C$, the mold temperature is $70-80^{\circ}C$, the injection time is about 1.2sec, the injection pressure and velocity is each 7.8-14.7Mpa, and the injection velocity is 0.8-1.2m/sec.

• 한국광학회지
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• 제26권4호
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• pp.226-232
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• 2015

$8m{\times}6m$(400인치)의 대형 화면 액정 화상 투영기에 쓸 수 있는 광원부로서 엘이디를 2층으로 촘촘하게 배열한 광원과 그에 수반되는 조명광학계 설계의 개념을 제시하였다. 엘이디를 촘촘히 배열할 때 생기는 방열문제는 엘이디를 2층으로 배열하면 해결됨을 열분석을 통해 보였다. 뒤 층의 엘이디에서 나오는 빛이 앞 층에 가려질 수 있는 문제는 앞뒤로 어긋나게 배열하여 해결했고, 엘이디 배열에서 나온 빛을 투영렌즈에 맞추어 액정판을 고르게 비추는 조명광학계를 함께 설계하였다.

• ETRI Journal
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• 제25권3호
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• pp.179-186
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• 2003

Using biometrics to verify a person's identity has several advantages over the present practices of personal identification numbers (PINs) and passwords. At the same time, improvements in VLSI technology have recently led to the introduction of smart cards with 32-bit RISC processors. To gain maximum security in verification systems using biometrics, verification as well as storage of the biometric pattern must be done in the smart card. However, because of the limited resources (processing power and memory space) of the smart card, integrating biometrics into it is still an open challenge. In this paper, we propose a fingerprint verification algorithm using a multi-resolution accumulator array that can be executed in restricted environments such as the smart card. We first evaluate both the number of instructions executed and the memory requirement for each step of a typical fingerprint verification algorithm. We then develop a memory-efficient algorithm for the most memory-consuming step (alignment) using a multi-resolution accumulator array. Our experimental results show that the proposed algorithm can reduce the required memory space by a factor of 40 and can be executed in real time in resource-constrained environments without significantly degrading accuracy.

• Current Optics and Photonics
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• 제1권3호
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• pp.207-213
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• 2017

The Adaptive Front-lighting System (AFS) is a part of the active safety system, providing optimized vision to the driver during night time and other poor-sight conditions of the road by automatic adaptation of lighting to environmental and traffic conditions. Basically, an AFS provides four different modes of the passing beam as designated in an United Nations Economic Commission for Europe regulation (ECE324-R123): neutral state or country light (Class C), urban light (Class V), highway light (Class E), and adverse weather light (Class W). In this paper, we first present an optics design for an AFS system capable of producing the Class C/V/E/W patterns requiring only on/off modulation of multi-array LEDs with no need for any additional mechanical components. The AFS optics consists of two separated modules, cutoff and spread; the cutoff module lights a narrow central area with high luminous intensity, satisfying the cutoff regulation, and the spread module forms a wide spread beam of low luminous intensity. Each module consists of two major parts; the first converts a discretely positioned LED array into a full-filled area emitting light source plane, and the second projects the light source plane to a 25 m away target plane. With the combination of these two optics modules, the four beam patterns are formed by simple on/off modulation of multi-array LEDs. Then we report the development of a prototype that was demonstrated to provide the four beam patterns.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.401-404
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• 2008

In the present investigation, a high precision thermal imprint system for micro ceramic products was developed and the net-shape manufacturing of multi-layer ceramic reflector for LED (Light Emitting Diode) was conducted with a precision metal die. Workpiece used in the present investigation were the multi-layer laminated ceramic sheets with pre-punched holes. The cavity with arbitrary angle was formed on the circular and rectangular holes of the ceramic sheets. During the imprinting process, the ambient temperature of the imprint system was kept over the transition temperature of the ceramic sheet and then rapidly cooled. The results in this paper show that the present method can be successfully applied to the fabrication of very small size hole array for ceramic reflector in a one step operation.

• ETRI Journal
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• 제28권5호
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• pp.545-554
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• 2006

A widely tunable multi-channel grating cavity laser is proposed and experimentally demonstrated. The device is implemented in Littman configuration with an echelle grating based on Rowland circle construction and realized by monolithically integrating all elements in an InP substrate. Lasing wavelength is selected by turning on an amplifier and the appropriate channel element in the array, and it is tuned by controlling light deflection electrically. The 6-channel device exhibits a tuning range of about 50 nm with a side mode suppression ratio of more than 30 dB. This is accomplished by adjusting the applied current of the dispersive element and phase control section.

• 한국콘텐츠학회논문지
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• 제10권2호
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• pp.43-53
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• 2010

유비쿼터스 컴퓨팅 기술들의 발달로 인해 인터랙티브 디스플레이는 사용자에게 다양한 인터랙션을 제공하고 있다. 이러한 인터랙션을 위해 다양한 방법들이 연구되었지만 디바이스 사용성과 단일 사용자에게 제공된다는 한계점이 발생하였다. 따라서 본 논문에서는 앰비언트 디스플레이 환경에서 다수 사용자에게 다양한 인터랙션을 제공하기위한 공간 멀티 인터랙션 인터페이스를 제안한다. 이를 위해 적외선 LED 배열바(IR-LEDs Array Bar)를 통해 사용자가 인터랙션 할 수 있도록 인터랙션 막을 생성한다. 이때 사용자는 인터랙션 막에서 공간 터치를 통해 다양한 인터랙션을 경험할 수 있다. 따라서 휴대 디바이스 없이도 사용자의 자연스러운 손동작만으로 인터랙션을 할 수 있는 인터랙티브 디스플레이 시스템과 인터페이스 방법을 제공한다.