Browsing by Author "Lu, Yen-Hsing"

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A localized partition approach for high-dynamic-range display
(2007)
Lu, Yen-Hsing
;
Cheng, Yu-Kuo
;
Tien, Chung-Hao
;
光電工程學系
;
Department of Photonics
A mosaic-form backlight system for high-dynamic-range display was introduced. The backlight unit consisting of a side-emitting LED, a quadratic light guide, and a concentric prism sheet can form an isolated square super-Gaussian distribution over the local area of liquid crystal panel. By means of our approach, high-dynamic-range display system can reduce the time required for processing compensated image signal.
A scanning backlight module for FSC-LCD using tandem light-guides with micro line-prism structures
(2008)
Lu, Yen-Hsing
;
Yao, Yuan-Jung
;
Hsiao, Jen-Chang
;
Tien, Chung-Hao
;
光電工程學系
A spatially partitioned backlight system composed of tandem wedge-shaped light-guides with micro line-prism arrays was developed for scanning held-sequential-color (FSC) LCD in large size. The light-guides combined with LED light-bars have been designed and fabricated to well distinguish each region and decrease the light leakage. By means of our approach, the volume of backlight system can be reduced down to 25 mm without sacrifice of the optical performance. As a result, 2750 nits average luminance subject to 50% duty cycle and 83% uniformity can be achieved. The leakages into the continuous adjacent blocks are well suppressed to 11.86%.
Design and Evaluation of Light Spread Function for Area-Adaptive LCD System
(2009-01-01)
Cheng, Yu-Kuo
;
Lu, Yen-Hsing
;
Tien, Chung-Hao
;
Shieh, Han-Ping
;
光電工程學系
A methodology, based on two-dimensional super-Gaussian light spread functions (LSFs), was studied for the light-emitting-diode (LED) backlighting system in the high dynamic range (HDR) liquid crystal displays (LCDs). We proposed a novel LED-based optomechanical configuration to implement the desirable luminous pattern. A dual-liquid-crystal-panel system was constructed as a pseudo-HIE)R LCD to evaluate the super-Gaussian illumination. The proposed HDR scheme was verified via the current platform: overall luminance uniformity, contrast ratio and processing speed could be improved by factors of 1.55, 1.95-4.15, and 4.82, respectively. The design flexibility made the methodology applicable to any panel dimension and backlight division of the HDR LCDs, and to the conventional full-on backlighting LCDs as well.
Design of mosaic-form LED backlight module
(2007)
Lu, Yen-Hsing
;
Tien, Chung-Hao
;
光電工程學系
;
Department of Photonics
A quadratic light-guide with micro-prismatic bump structures for illumination of the liquid crystal display (LCD) system has been developed. The functional light-guide combining with a side-emitting light-emitting-diode (LED) and a concentric prism sheet (CPS) is able to illuminate a uniformly square distribution over the LC panel. Through the assembly of these kinds of optical elements, the mosaic-form LED backlight module can be applied to any dimension of a panel associated with relational parameters with proportional quantities. According to our simulation, the proposed system can increase the output efficiency from roughly 50 % (without any optical elements) to 75 % and maintain the brightness uniformity of 88. 3 % as well.
LED light lit for field-sequential-color backlight system
(2007)
Chien, Ming-Chin
;
Chen, Cho-Chih
;
Yang, Su-Chin
;
Lu, Yen-Hsing
;
Kuo, Hao-Chung
A 7-inch backlight module consisting of ten isolated micro-structured linear light pipes and two side-collimating bars was developed with serial full-color Light Emitting Diodes (LEDs) as light source for a field-sequential-color liquid-crystal display (FSC-LCD) system. The collimating lighting system not only yields a narrow angular light distribution, but also effectively diminishes the occurrence of color dependence in the scanning backlight for FSC applications. For each linear light pipes, only 3. 6 % of optical power leaked out to the neighboring divisions, meanwhile, the divergent angles of extraction light were controlled to +/- 17 degrees and +/- 31 degrees at two orthogonal directions respectively.
Optical element apparatus for two-dimensional controllable localized partition backlight module
(2009-07-02)
Tien, Chung-Hao
;
Lu, Yen-Hsing
;
Cheng, Yu-Kuo
;
Lu, Po-Yi
The optical element apparatus for two-dimensional controllable localized partition backlight module is disclosed. The optical element apparatus comprises of a plurality of optical units which include a plurality of point light sources, light guides and collimating sheets. The point light source is located at the center of the light guide. The light guide includes the incident surface, the bottom place connecting with the light incident surface, and the light output surface. There are micro structures on the bottom place of the light guide and the top surface of the collimating sheet.
Principal Component Analysis of Multi-Pigment Scenario in Full-Color Electrophoretic Display
(2013-10-01)
Lu, Yen-Hsing
;
Tien, Chung-Hao
;
光電工程學系
;
Department of Photonics
In this paper, we present a methodology to characterize the colorimetric performance of a full-color electrophoretic display (EPD) with multiple pigment formation. We use the principal component analysis to formulate the composite hybrid color-mixing system by using a single eigen-spectral component for each sub-pixel channel. Proposed model was validated to predict the chromatic features with high accuracy (Delta E-AVE_CIEDE2000 < 0.2) for both micro-cup type and micro-encapsulated type EPD samples. This study is effective to uncover the underlying physical features from only colorant-mixture information in a novel color system.
Principal Component Analysis of Multi-Pigments Transposition in Full-Color Electrophoretic Display
(2012)
Lu, Yen-Hsing
;
Chiu, Yu-Hsun
;
Tien, Chung-Hao
;
光電工程學系
;
顯示科技研究所
A methodology is introduced to characterize colorimetric performance of full-color electrophoretic display. The concept of principal component analysis benefited simplifying the complicated hybrid color-mixing system by means of the spectral eigenvectors. Proposed model was validated to predict the chromatic feature with high accuracy (Delta E-AvE_(CIEDE2000)< 0.2). Due to its simplicity and invertibility, proposed technique will certainly has a promising impact on the color reproduction or characterization in emerging novel displays associated with hybrid color-mixing system.
Region-partitioned LED backlight design for field sequential color LCD
(2007)
Chien, Ming-Chin
;
Tien, Chung-Hao
;
Chen, Cho-Chih
;
Lu, Yen-Hsing
;
光電工程學系
In this paper, a 7-inch backlight module consisting of ten isolated micro-structured linear light pipes and two side-collimating bars was developed with serial full-color LEDs as light sources for a field-sequential-color liquid-crystal display (FSC-LCD) system. The collimating lighting system not only yields a narrow angular light distribution, but also effectively diminishes color dependence in the scanning backlight for FSC applications. The crosstalk of the light from each linear light pipe leaking out to the neighboring divisions was measured; meanwhile, the divergent angles of extraction light were well controlled to about +/- 17 degrees and +/- 30 degrees at two orthogonal directions respectively.
Super-Gaussian light spread function for high dynamic range displays
(2008)
Cheng, Yu-Kuo
;
Lu, Yen-Hsing
;
Lu, Po-I
;
Tien, Chung-Hao
;
Shieh, Han-Ping D.
Super-Gaussian light spread function was designed for high dynamic range liquid crystal displays. A dual-liquid-crystal-panel system was constructed to simulate an HDR display, and to evaluate the implementation of the proposed super Gaussian and a general Gaussian distributions. According to the results, luminance uniformity, and processing time of super-Gaussian LSF are superior to those of Gaussian LSF by factors of 1.55 and 178, respectively. Contrast ratio is improved by a factor about 2 to 4.15 as well. In addition, the undesired artifact, grid lines, can be suppressed to be invisible.
Tandem light-guide with prismatic micro-bumps structures for field-sequential-color scanning backlight module
(2007)
Yao, Yuan-Jung
;
Lu, Yen-Hsing
;
Tien, Chung-Hao
;
顯示科技研究所
;
Institute of Display
A field-sequential-color (FSC) scanning backlight system with tandem light guides (LGs) is introduced for a 32-inch color-filter-less liquid-crystal display (LCD). The tandem-type backlight module (BLM) can clearly define each scanning division without any shields and reduce the total thickness of the module down to 15 mm at the same time. According to the experiment, uniformity and efficiency were achieved upto 83% and 63% respectively using prismatic micro-bump structures over the bottom of LG. Light leakage to the adjacent partition was measured 9.8% as well. Based on the tandem optomechanical setup, the influences of image blur and color-breakup (CBU) from motion pictures were expected to be significantly reduced accordingly.
Tandem light-guides with micro-line-prism Arrays for field-sequential-color scanning backlight module
(2008-06-01)
Tien, Chung-Hao
;
Lu, Yen-Hsing
;
Yao, Yuan-Jung
;
光電工程學系
;
顯示科技研究所
An optically partitioned backlight system of tandem wedge-shaped light-guides (LGs) with arrays was developed for scanning field-sequential-color liquid crystal display (LCD) in large size. The unit of LG combined with a light-emitting diode (LED) light-bar designed and fabricated to collimate the extraction light a narrow angular extent. Based on the edge lighting the volume of backlight system can be reduced down to 25 without sacrifice of the optical behavior. As a result, 2750 average luminance subject to 50% duty cycle and 83% can be achieved. The leakages into the consecutive adjacent were well suppressed to 11.86%.