Browsing by Author "Chao, Wei-Chung"

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A Novel Architecture for Autostereoscopic 2D/3D Switchable Display Using Dual Layer Strip Patterned OLED Backlight Module
(2014-05-01)
Wang, Yi-Jun
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Liu, Jun
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Tan, Jian
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Yang, Bo-Ru
;
Ding, Wei-Xian
A novel backlight module that integrates dual layer strip patterned organic light emitting diode (DLSP-OLED) for 2D/3D switchable display was demonstrated. The DLSP-OLED functions as a parallax barrier in 3D mode and a planar light source in 2D mode. The results indicated that the backlight module with a thin form factor (similar to 1.1 mm) can achieve uniformity of 91% in 2D mode, and increased optical efficiency by a factor of 2.8 with a crosstalk of less than 6% in 3D mode, compared with the conventional 2D/3D switchable display. A fast switching rate (<1 ms) with simple operation can eliminate the visual fatigue caused by flicker during the switching. In addition, this configuration can function localized 3D display by modulating the DLSP-OLED individually.
Contrast-sensitivity-based evaluation method of a surveillance camera's visual resolution: improvement from the conventional slanted-edge spatial frequency response method
(2017-02-10)
Qin, Zong
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Wong, Po-Jung
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Chao, Wei-Chung
;
Lin, Fang-Cheng
;
Huang, Yi-Pai
Visual resolution is an important specification of a surveillance camera, and it is usually quantified by linewidths per picture height (LW/PH). The conventional evaluation method adopts the slanted-edge spatial frequency response (e-SFR) and uses a fixed decision contrast ratio to determine LW/PH. However, this method brings about a considerable error with respect to subjectively judged results because the perceptibility of the human vision system (HVS) varies with spatial frequency. Therefore, in this paper, a systematic calculation method, which combines the contrast sensitivity function characterizing the HVS and e-SFR, is proposed to solve LW/PH. Eight 720P camera modules in day mode, four 720P modules in night mode, and two 1080P modules in day mode are actually adopted. Corresponding to the three modes, mean absolute error between objective and subjective LW/PH are suppressed to as low as 26 (3.6% of 720P), 27 (3.8% of 720P), and 49 (4.5% of 1080P), while those of the conventional method are 68 (9.4% of 720P), 95 (13.2% of 720P), and 118 (10.9% of 1080P).(C) 2017 Optical Society of America
High directional backlight using an integrated light guide plate
(2015-01-26)
Wang, Yi-Jun
;
Ouyang, Shi-Hong
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Chao, Wei-Chung
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Lu, Jian-Gang
;
Shieh, Han-Ping D.
A high directional backlight system that combined a composite microstructure light guide plate (LGP) with a collimated light source was proposed for eco-displays. The collimated planar light was expanded from a point light source and guided towards the normal direction by utilizing the micro-prism array on LGP. High uniformity of spatial luminous, 91%, with a narrow viewing cone of +/- 4 degrees can be achieved without additional optical films. Moreover, compared to the conventional backlight, only 5% of power consumption was needed to keep the same luminance, hence, the optical efficiency increased by a factor of 1.47. (C) 2015 Optical Society of America
Switchable viewing angle display with a compact directional backlight and striped diffuser
(2015-08-10)
Wang, Yi-Jun
;
Lu, Jian-Gang
;
Chao, Wei-Chung
;
Shieh, Han-Ping D.
;
光電工程學系
A compact high-directionality backlight module combined with a striped diffuser is proposed to achieve an adjustable viewing angle for ecodisplay. The micro-prisms on the compact light guide plate guide the emitting rays to the normal viewing angle, whereas a set of striped diffusers scatter the rays to a wide viewing angle. View cones of +/- 10 degrees/+/- 55 degrees were obtained for narrow/wide viewing modes with 88%/85% uniformity of spatial luminance, respectively. Compared with the conventional backlight, the optical efficiencies were increased by factors of 1.47 and 1.38 in narrow and wide viewing modes, respectively. In addition, only 5% of power consumption was needed when the backlight worked in private narrow viewing mode to maintain the same luminance as that of a conventional backlight. (C) 2015 Optical Society of America