• 한국전기전자재료학회논문지
• /
• 제17권3호
• /
• pp.311-318
• /
• 2004

We have studied electro-optic characteristics as a function of pretilt angle ($\theta$$_{p}$) in the fringe-field switching (FFS) mode using the LC with positive dielectric anisotropy. When $\theta$$_{p}$ is increased from 0$^{\circ}$ to 20$^{\circ}$, a maximum transmittance and an operating voltage are obviously decreased. In the viewing angle characteristics, the cell with low pretilt angle has a wide region for the contrast ratio greater than 5 and has a best luminance uniformity. Therefore, in the FFS device, a low pretilt angle is favored for high transmittance and wide viewing angle.gle.

• Journal of Information Display
• /
• 제8권4호
• /
• pp.10-14
• /
• 2007

LCD performance is generally evaluated in terms of luminance and color versus viewing angle. In the present paper, we show that this type of display can be favorably characterized in terms of polarization. We show that ELDIM EZContrast instrument which is routinely used for viewing angle measurements can be upgrade for measuring the polarization state of the light at each incidence and azimuth angle. More precisely, the degree of polarization of light, its ellipticity and polarization direction can be measured at each incidence angle between 0 and $88^{\circ}$ and for all the azimuth angles (from 0 to $360^{\circ}$). Important differences between the displays can be detected and related to their internal structures when luminance and color profiles are quite similar. The same setup can also be used to characterize optical components of the LCDs.

• 대한인간공학회지
• /
• 제33권3호
• /
• pp.191-202
• /
• 2014

Objective: This study is conducted on the differences between flat and curved displays with respect to location of focused points, posture and satisfaction as well as preferred tilt angles. Background: In order to avoid physical and eye fatigue caused by misplayed sitting posture, many studies have asserted that the display requires appropriate location, size and tilt angle as well as curvature. However, most studies have focused on the work environment and the results are varied in the extent. Method: Eye height data in sitting posture were collected from 30 participants. Participants selected the most comfortable viewing angle within the range from $0^{\circ}$ to $12^{\circ}$ while watching videos for both curved and flat display. Then, physical and eye fatigue and overall satisfaction were subjectively evaluated. Lateral diagram describing viewing display condition was set and used to develop linear models for expecting the preferred tilt angle. Results: Due to sitting in the natural viewing posture rather than upright, the eye height is lowered to about 4.6 centimeters, on average, for both displays showing no significant differences. In contrast, preferred angles for the two displays are significantly different and this can be interpreted that curvature vary the points focused. Two linear models as functions of sitting eye height are developed to expect preferred tilt angle for each display. Based on the result of overall satisfaction evaluation, curved display is statistically better than flat display. Conclusion: The results show that flat and curved displays are significantly different expect for the viewing posture. However, reasons for preferring curved display are not accurately factorized and the linear models are limited in the experiment condition such as size of display, distance between display and viewer and other physical environmental factors. Further studies on curved displays under more various conditions are required. Application: This study can contribute to use of the curved display in various way.

• ETRI Journal
• /
• 제31권2호
• /
• pp.105-110
• /
• 2009

In this paper, we propose a curved projection integral imaging system to improve the horizontal and vertical viewing angles. The proposed system can be easily implemented by additional use of a large-aperture convex lens in conventional projection integral imaging. To obtain the simultaneous display of 3D images through real and virtual image fields, we propose a computer-generated pickup method based on ray optics and elemental images, which are synthesized for the proposed system. To show the feasibility of the proposed system, preliminary experiments are carried out. Experimental results indicate that our system improves the viewing angle and displays 3D images simultaneously in real and virtual image fields.

• Journal of the Optical Society of Korea
• /
• 제16권4호
• /
• pp.365-371
• /
• 2012

A three-dimensional integral-floating display with 360 degree horizontal viewing angle is proposed. A lens array integrates two-dimensional elemental images projected by a digital micro-mirror device, reconstructing three-dimensional images. The three-dimensional images are then relayed to a mirror via double floating lenses. The mirror rotates in synchronization with the digital micro-mirror device to direct the relayed three-dimensional images to corresponding horizontal directions. By combining integral imaging and the rotating mirror scheme, the proposed method displays full-parallax three-dimensional images with 360 degree horizontal viewing angle.

• 한국광학회지
• /
• 제33권2호
• /
• pp.67-73
• /
• 2022

가상현실(virtual reality) 구현을 위한 헤드마운트 디스플레이는 사용자의 눈과 가까이 위치하고, 화면의 위치가 고정되어 있기 때문에 좁은 시야각이 소비전력 측면에서 유리하다. 본 논문에서는 광시야각에 최적화된 일반적인 액정 디스플레이(liquid crystal display, LCD)에서 헤드마운트 디스플레이에 적합한 협시야각 구현을 위한 back light unit (BLU) 구조를 연구하였으며 도광판의 산란 패턴과 역프리즘 구조를 최적화함으로써 시야각을 제어할 수 있는 구조와 각 인자들 간의 상관관계를 시뮬레이션으로 분석하였다. 그 결과 도광판의 산란 패턴의 형태에 대응되는 이중각 역프리즘 구조를 선정하였고, 이는 기존의 일반적인 LCD 대비 휘도 14% 증가, 상하 시야각은 16% 감소, 최대 70%의 광효율의 결과를 얻었다. 이 구조는 기존의 불필요한 광손실을 제거한 고효율 LCD로서의 활용이 기대된다.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
• /
• pp.1615-1618
• /
• 2007

Performances of LCDs are generally evaluated in terms of luminance and color versus viewing angle. In the present paper we show that this type of display can be favorably characterized in terms of polarization. We show that ELDIM EZContrast instrument can be used to measure the degree of polarization the light and the ellipticity and polarization direction of the polarized component. This measurement is made versus incidence angle between 0 and $88{\circ}$ and for all the azimuth angles. Important differences between the displays can be detected and related to their internal structures when luminance and color profiles are quite similar.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
• /
• pp.15-18
• /
• 2004

Recent progress of the in-plane switching (IPS) TFT-LCD technologies is reviewed. We call the improved new technology 'advanced super IPS TFT-LCD(AS-IPS)'. After suppressing the viewing angle dependency of essential display characteristics, recent brightness, viewing angle and motion picture quality has been highly improved. The stage is now introducing it into consumer information appliance for higher display performances, by which we could open a large size digital LCD TVs application.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
• /
• pp.608-610
• /
• 2003

In the paper, we have investigated the reflective cholesteric display based on the polymer stabilization. The bistability in the polymer stabilized cholesteric texture(PSCT) films was observed and wider viewing angle was achieved due to imperfect planar texture.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
• /
• pp.7-8
• /
• 2000

We compared various LCD modes for wide viewing angle. These modes can be classified as film-compensation, multi-domain, IPS. So far, IPS and multi-domain VA represent best performance. The performance gap with respect to CRT is diminishing.