Improvement of image quality of liquid crystal projection system by a diffractive gratings

1998 ◽  
Vol 29 (1) ◽  
pp. 671 ◽  
Author(s):  
Cheng-Ko Wu ◽  
Fu-Jen Ko ◽  
Han-Ping. D. Shieh
Keyword(s):  
Liquid Crystal ◽  
Image Quality ◽  
Projection System

Image Quality of Two-Primary Color Active-Matrix Liquid-Crystal Displays

1997 ◽  
Vol 39 (4) ◽  
pp. 618-641 ◽  
Author(s):  
David L. Post ◽  
William F. Reinhart
Keyword(s):  
Liquid Crystal ◽  
Image Quality ◽  
Liquid Crystal Display ◽  
Active Matrix ◽  
Primary Color ◽  
Aperture Ratio ◽  
Full Color ◽  
Series Of Experiments ◽  
Matrix Liquid

The demand for color head- and helmet-mounted displays (HMDs) is growing. Interest focuses on full-color systems, but a limited color repertoire is sufficient for some applications and can reduce cost and complexity significantly, especially when subtractive-color active-matrix liquid-crystal display (AMLCD) technology is used. We report a series of experiments that investigated important questions about the design and merits of two-primary color AMLCDs for HMD applications. Our main conclusion is that the image quality of a subtractive-color AMLCD with high (≥70%) aperture ratio is superior to a comparable, conventional color AMLCD. Evidence regarding requirements for resolution, aperture ratio, and gray scale is also provided.

Moving image quality of liquid crystal display based on human factor

2020 ◽  
Vol 35 (10) ◽  
pp. 1051-1058
Author(s):  
Yu SONG ◽  
◽  
Zhen-ping XIA ◽  
Fu-yuan HU ◽  
Cheng CHENG ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Image Quality ◽  
Human Factor ◽  
Liquid Crystal Display ◽  
Moving Image

scholarly journals Enhancement of Image Quality in LCD by Doping γ-Fe2O3 Nanoparticles and Reducing Friction Torque Difference

Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 911 ◽  
Author(s):  
Lin Gao ◽  
Yayu Dai ◽  
Tong Li ◽  
Zongyuan Tang ◽  
Xueqian Zhao ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Image Quality ◽  
Liquid Crystal Display ◽  
Friction Torque ◽  
Fe2o3 Nanoparticles ◽  
Dc Voltage ◽  
Absolute Value ◽  
Combined Action ◽  
Cell Capacitance

Improving image sticking in liquid crystal display (LCD) has attracted tremendous interest because of its potential to enhance the quality of the display image. Here, we proposed a method to evaluate the residual direct current (DC) voltage by varying liquid crystal (LC) cell capacitance under the combined action of alternating current (AC) and DC signals. This method was then used to study the improvement of image sticking by doping γ-Fe2O3 nanoparticles into LC materials and adjusting the friction torque difference of the upper and lower substrates. Detailed analysis and comparison of residual characteristics for LC materials with different doping concentrations revealed that the LC material, added with 0.02 wt% γ-Fe2O3 nanoparticles, can absorb the majority of free ions stably, thereby reducing the residual DC voltage and extending the time to reach the saturated state. The physical properties of the LC materials were enhanced by the addition of a small amount of nanoparticles and the response time of doping 0.02 wt% γ-Fe2O3 nanoparticles was about 10% faster than that of pure LC. Furthermore, the lower absolute value of the friction torque difference between the upper and lower substrates contributed to the reduction of the residual DC voltage induced by ion adsorption in the LC cell under the same conditions. To promote the image quality of different display frames in the switching process, we added small amounts of the nanoparticles to the LC materials and controlled friction technology accurately to ensure the same torque. Both approaches were proven to be highly feasible.

A Control Algorithm of LCD Dynamic Backlight Based on PSNR

2012 ◽  
Vol 241-244 ◽  
pp. 3014-3019 ◽  
Author(s):  
Xiao Bing Zhang ◽  
Xin Liu ◽  
Bo Liu ◽  
Jiang Hong Han ◽  
Hua Xia Wu
Keyword(s):  
Liquid Crystal ◽  
Image Quality ◽  
Power Consumption ◽  
Control Algorithm ◽  
Signal To Noise Ratio ◽  
Liquid Crystal Display ◽  
Gray Level ◽  
Quality Requirement ◽  
Signal To Noise

A new algorithm is proposed to adjust backlight luminance for local dimming of liquid crystal display (LCD) devices. PSNR (the peak signal-to-noise ratio) =30 is acted as the lowest standard to guarantee the quality of image in the algorithm. Based on the formula of PSNR=30, the square error value of the image distortion is gained. Then, luminance of backlight is gained dynamically by that the maximum gray level minus 1 into the formula proposed in the paper and decreases by one after each trial if the image quality requirement is not satisfied. In order to simplify the calculation, three important gray level values are selected to meet the requirements. The results show that the algorithm can greatly reduce the power consumption with guaranteeing the image quality and furthermore save much time in calculation and be better applied in hardware.

scholarly journals Enhanced image quality of OLED transparent display by cholesteric liquid crystal back-panel

2017 ◽  
Vol 25 (23) ◽  
pp. 29199 ◽  
Author(s):  
Cheng-Chang Li ◽  
Heng-Yi Tseng ◽  
Hung-Chia Liao ◽  
Han-Ming Chen ◽  
Ting Hsieh ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Image Quality ◽  
Cholesteric Liquid Crystal ◽  
Back Panel ◽  
Transparent Display
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