• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.30-33
• /
• 2003

In this paper the advantage of web technology applied to Rapid Prototyping is discussed. Two fabrication processes are chosen to be web-enabled. One, a post-process of FDM is developed to provide translucent plastic parts made of medical grade ABS material. The other, a system to fabricate laser machined Light Guide Panel is developed. In order to show the timesaving characteristics of the web-based tools, two websites are implemented (http://nano.gsnu.ac.kr/fdm ＆ http://nano.gsnu.ac.kr/laser). The 3-tier architecture is applied for the Internet communication between designers and manufacturing sites, The integrated design tools and physical manufacturing processes enable designers to submit a new design and to receive the fabricated parts in an expedited manner. Example parts are fabricated using the web-based system to prove the concept of the web-based design and Rapid Prototyping.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2006년도 춘계학술대회 논문집
• /
• pp.91-94
• /
• 2006

In this paper, in order to get micro or nano size optical patterns, an analytical and experimental investigation on a LGP (light guide plate) injection molding process has performed. The LGP, which diffusing and emitting the light from the CCFL or the LEDs to the panel front direction uniformly, typically has an under 1mm thick base substrate and numerous 60 to $170{\mu}m$ width and 6 to $10{\mu}m$ thick dot patterns on it. Generally, the small size LGPs, for mobile devices, have been and are being made of PMMA through the injection molding process. However, the substrate thickness and the dot pattern size are decreasing, it becomes hard to fill the micro to sub-micro cavities completely. To investigate the flow behavior of resin in micro/nano cavities and identify the characteristics of the LGP injection molding process, we carried out the flow analyses with respect to the variations of the substrate thickness, the dot pattern size and the pitch of a cavity.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2003년도 춘계학술대회 논문집
• /
• pp.1215-1219
• /
• 2003

Light Guide Panel(LGP) is a key part of backlight unit(BLU) which transforms line-light of lamp to surface-light. Dot pattern is formed on the injected LGP surface by screen printing. This dot pattern is composed of several ten thousands micro dots of diameter 150-180$\mu\textrm{m}$ or so. The dot patterning by screen printing causes low productivity and low performance of TFT-LCD. This research develops the micromachining technology for LGP mould which could form micro dot pattern by injection molding, removing the existing screen printing process.

• 반도체디스플레이기술학회지
• /
• 제18권4호
• /
• pp.25-29
• /
• 2019

Microstructure pattern generation on light guides in backlight unit (BLU) is an essential process for designing flat panel display, but efficient designing algorithm is still limited to achieve uniform luminescence while maintaining fully random distribution to avoid interference effects. In this study, a molecular dynamics model based pattern generation algorithm has been developed. The proposed algorithm allows a fast and efficient distribution of patterns at specified density within the user-defined computational cells, and its efficiency and performance has been demonstrated with sample cases.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2009년도 추계학술대회 논문집
• /
• pp.99-102
• /
• 2009

The recent LCD TV market has made efforts to produce thinner, brighter, and clearer products, and experienced the rapid light source replacement from a line source of light CCFL to a point source of light LED. In particular, LGP(Light Guiding Panel) among key parts composing BLU(Back Light Unit) has limits of the injection molding technology as well as the mold design, its processing and manufacturing technology so that it is hard to produce large LGP over 40 inch. To produce large light-guide panels over 40 inch under the injection molding process, a mold 3D model was developed in the design process before manufacturing a mold and structure unification was processed through CAE analysis. As a result, it was possible to construct the mold design process, and it is expected to manufacture the optimized mold by applying the mold design and manufacturing process of large-scale rapid injection-compression molding that will be produced in the future.

• 대한기계학회논문집A
• /
• 제33권8호
• /
• pp.720-725
• /
• 2009

Among many kinds of parts for Liquid Crystal Display (LCD), a Back Light Unit (BLU) that changes the path of the light from light source to screen is the most important part to improve optical performances such as uniformity and average value of brightness. Up to recently, design process of BLU has been carried out by depending on the experience of design engineer. Using this approach, however, is proven that it is hard to effectively deal with difficulties in a process of the LCD development such as frequent design modifications, various design requirements, and short-term development. To cope with this situation, we applied a Process Integration and Design Optimization (PIDO) based design environment. PIDO is a software package to integrate multiple simulation processes and find a better solution using various design techniques. In this research, we found a design solution satisfying all design requirements by using the PIDO.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2005년도 추계종합학술대회
• /
• pp.759-762
• /
• 2005

The LGP(Light Guide Panel) for the back light unit that is used to the 2.2" TFT LCD was designed and fabricated. The method of the pattern design which is the most important in the design of the LGP was converted the V-cutting method into the Dot method. This newly developed Dot method provided a good uniformity in the brightness at the LGP, which was a very difficult problem to solove in the V-cutting method. The experiment result of the newly designed LGP shows the brightness uniformity 90% and the brightness 3656 $cd/\;m^2$ which is 20% higher than the commercial products.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
• /
• pp.580-582
• /
• 2004

As the demand of large and high-resolution display panels is increased, the black light units (BLU) of the display devices play an important roles. In this study we'll deal with various defects of BLUs. Patterns of defects can be classified by the scratches, the non-uniform misprinting for the diffused reflection, the surface stains, spots and etc. Due to these distorted patterns the high-resolution and high-precision could be impeded. We'll propose the visual inspection system to detect various defects by pattern-matching.

• 한국광학회지
• /
• 제21권2호
• /
• pp.61-68
• /
• 2010

최근 LED TV로 각광받고 있는 대형 LCD TV용 LED(Light Emitting Diode, 고체발광다이오드) 백라이트에 사용되는 도광판의 광구조를 최적화하여 LED에 의해 발생하는 휘점을 제거하고 조도균일도를 향상시키기 위한 시뮬레이션 연구를 진행하였다. 시뮬레이션 모델로 설정된 엣지형 백라이트는 LCD TV용으로 사용될 수 있는 두께 3 mm의 도광판, 측면에 배치된 세 개의 백색 LED와 램프 커버, 도광판의 하면에 배치된 반사 필름으로 구성되어 있다. 일반적인 엣지형 백라이트용 도광판과 같이 도광판의 입광면에 패턴이 형성되어 있지 않은 경우에는 도광판 상면의 조도균일도가 입광면과 LED 사이의 거리에 민감하게 의존하였다. 입광면과 LED 사이의 거리가 커질수록 조도균일도는 개선되다가 일정 거리 이상이 되면 개선이 둔화되는 경향성을 보였다. 반면에 도광판의 입광면에 렌티큘라(lenticular) 렌즈 배열이나 톱니모양(Serration)과 같은 미세 굴절 패턴을 형성하는 경우 LED가 입광면에 거의 붙어 있는 경우에도 패턴이 없는 경우에 비해 우수한 조도균일도를 보인다는 것을 알 수 있었고 조도균일도가 LED와 입광면 사이의 거리에 의존하는 정도가 줄어든다는 점도 확인하였다. 동일조건에서는 톱니모양 패턴이 렌티큘라 렌즈에 비해 우수한 조도균일도를 나타내었고 굴절률의 변화를 통해 추가적인 균일도 개선 효과를 얻을 수 있음도 확인하였다. 따라서 도광판의 입광면에 굴절 기능을 가지는 미세 패턴을 형성하고 그 광구조를 최적화하는 것은 LED에 의한 휘점 형성을 억제하고 LCD 측면의 비발광영역(베젤)을 줄이는데 있어서 매우 효과적인 방법이 될 수 있다는 것을 확인하였다.

• 한국기계가공학회지
• /
• 제4권4호
• /
• pp.28-33
• /
• 2005

Recently, trends of TFT-LCD toward larger scale and thinner thickness continue. so, demands of Light Guide Panel (LGP) which is to substitute for prism sheet are appeared. Functions of LGP obtaining polarization of light of the prism sheet as well as the incidence and reflection of light are demanded. This prism type LGP to complete functions of the existing LGP and polarization at once must be supported by micro machining technology of LGP surface. In this research, the machining characteristics of the various materials were analysed by shaping using V-shaped single crystal diamond tool. The characteristics are machined surface, machining force due to the variation of cutting depth. Used specimens are engineering materials, which are 6:4 brass, oxygen-free copper, Al6061, PC, PMMA. The FFT analysis of the measured cutting force was conducted. The cutting characteristics were analyzed and the optimum cutting conditions with materials were established.