Browsing by Author "Ho, Ming-Tsung"

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Gray level redistribution in field sequential color LCD technique for color breakup reduction
(2008)
Chen, Chun-Ho
;
Chen, Ke-Horng
;
Huang, Yi-Pai
;
Shieh, Han-Ping D.
;
Ho, Ming-Tsung
A gray level redistribution for color filterless liquid crystal displays (LCDs) was proposed to suppress the color breakup (CBU) artifact on field sequential color (FSC) displays. This method discolors the primary color fields and redistributes the color intensities to a color-mixed field. The algorithm based on the image content was developed and implemented on a 32-inch panel. According to the evaluation of experiments and observations, the proposed method has been demonstrated to greatly suppress CBU in LCD applications.
High efficiency and/or low cost LED backlight system for color sequential technique in color filter-less LCD system
(2008)
Hsieh, Chun-Yu
;
Wang, Shih-Jung
;
Lee, Yu-Huei
;
Chen, Ke-Horng
;
Ho, Ming-Tsung
This paper proposes a design methodology for implementing a high efficiency and/or a low cost RGB backlight module in color sequential notebook computers' display. A RGB LED driver composed of an asynchronous 1.5MHz DC/DC boost converter with dual loop control is fabricated by TSMC 0.25 mu m BCD 40V to generate 17V or 21V output voltage to turn on more than 6 series-red, 6 series-green, or series-blue LEDs at the same time for the notebooks' backlight. Besides, charge-recycling technique is used to restore extra energy at the output node when switching to different forwarding light emitting diodes (LEDS) and release the energy new time. The total power consumption of a 15.4' LCD panel of a notebook computer can be reduced from 5W to about 2-3 W.
RGB LED Backlight of Color Sequential Display with Precise Current-Balance Control Technique
(2009)
Chiu, Chia-Lin
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Lee, Yu-Huei
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Hsieh, Chun-Yu
;
Ho, Ming-Tsung
;
Chen, Ke-Horng
This paper proposes a high efficiency and precise current balance circuit in parallel RGB Light Emitting Diodes (LED) channels for color filter-less panel display. The new technique not only enhances the current matching in each channel but also reduces the requirement of device numbers and external resistors. The error percentage of all channel LED currents can kept within 0.1% when the channel voltage has a voltage variation ((Delta) V(CH)) around 1.IV. Furthermore, the proposed load dependent minimum drain voltage can effectively reduce the voltage drop across the precise current balance circuit. As a result, the efficiency of the LED driver can be improved.
Spatial-temporal division in field sequential color technique for color filterless LCD
(2007)
Chen, Che-Chin
;
Chen, Yi-Fu
;
Liu, Ti-Ti
;
Chen, Chun-Ho
;
Ho, Ming-Tsung
For color filterless display, a novel spatial and temporal division (STD) field sequence color (FSC) display technique divides each frame into many temporary sub-frames for improving color breakup (CBU) and motion blur effects. Fast refresh frequencies enhance the image quality. Spatial and temporal division achieves low cost and power consumption.