Browsing by Author "Li, Chang-Yi"

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A hybrid simulated method for analyzing the optical efficiency of a head-mounted display with a quasi-crystal OLED panel
(2014-03-10)
Chang, Kao-Der
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Li, Chang-Yi
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Pan, Jui-Wen
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Cheng, Kuei-Yuan
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光電系統研究所
Organic light emitting diodes (OLEDs) with a quasi-crystal (QC) structure are analyzed and applied in a head-mounted display (HMD) system in this study. We adopt a hybrid simulated method to evaluate the light extraction efficiency (LEE) and far-field pattern in the air, and study the relationship between them. The simulation results show that OLEDs implanted with the QC structure can provide a collimated far-field pattern to increase the brightness. Using this 10-fold QC arrangement the maxima LEE of the OLEDs can be increased by 1.20 times. Compared with conventional OLEDs, the viewing angle of the OLED panel decreases from 120 degrees to 26 degrees with an improvement in the optical efficiency of the HMD system by 2.66 times. Moreover, the normalized on-axis intensity in the pupil of the eyepiece can be enlarged up to 3.95 times which suggests that the OLED panel can save 74.68% energy while achieving the same onaxis intensity as conventional OLEDs. (c) 2014 Optical Society of America
High-efficiency backlight module with two guiding modes
(2014-03-10)
Li, Chang-Yi
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Pan, Jui-Wen
;
光電系統研究所
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生醫電子轉譯研究中心
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Institute of Photonic System
We propose a design for a high-efficiency backlight module that does not require a brightness enhancement film (BEF). With the high-efficiency backlight module it is possible to achieve almost the same half-luminance angle as a conventional edge-lit backlight module can achieve. The backlight system is comprised of a crisscross light guide plate (LGP) and one diffuser sheet. The crisscross LGP is composed of a LGP and optically patterned film (OPF). The backlight module allows light to be extracted through the direct guiding mode and top guiding mode, respectively. We controlled arrangement of the microstructures to increase the optical efficiency and the uniformity by two modes. Compared to the conventional edge-lit backlight module, there is a two-fold improvement in both the total optical efficiency and on-axis luminance with the high-efficiency backlight module. (C) 2014 Optical Society of America