Ke-Horng Chen

Mixed Color Sequential Technique for Reducing Color Breakup and Motion Blur Effects

This paper proposes a mixed color sequential (MCS) algorithm with high contrast enhancement technique in RGB light-emitting diode (LED) backlight display. Owing to synchronous control of liquid crystal display (LCD) and LED panels, high quality image with suppressed color breakup (CBU) and motion blur effects is achieved by our novel color sequential technique. Importantly, MCS algorithm is useful for color filter-less optical compensated bend (OCB) panel display for alleviating CBU and motion blur effects. Furthermore, high contrast image is also presented on LCD panel because of mixed red-green-blue (RGB) and cyan-magenta-yellow (CMY) backlights with optimum power consumption. In other words, MCS algorithm with high contrast enhancement technique can have the better performance compared with other field sequential color techniques. Experimental results demonstrate by an actual RGB backlight module for 32-in 1366*768 LCD panel the improvement of CBU and motion blur effects.

Adaptive LC/BL Feedback Control in Field Sequential Color LCD Technique for Color Breakup Minimization

A full-color image on field sequential color (FSC) displays is composed of color fields in temporal sequence. With the FSC mechanism, color filters of liquid crystal displays (LCDs) can be removed to heighten the light efficiency and lower the material cost. Color breakup (CBU), however, has appeared intrinsically to degrade visual qualities. A novel gray level determination of liquid crystal and backlight (LC/BL) was proposed to suppress the CBU artifact on FSC-LCDs. Based on the image content in each frame, a dominated color-mixed field was found to minimize the color difference between the CBU and original image. Additionally, the feedback algorithm for the adaptive LC/BL signals was developed and implemented on a 32-inch optically compensated bend (OCB) mode LC panel. According to the evaluation of experiments and observations, the proposed method has been demonstrated to greatly suppress CBU in LCD applications.

66.4: Spatial‐temporal Division in Field Sequential Color Technique for Color Filterless LCD

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. Keywords: field sequential color, liquid crystal display, color breakup, color filterless, Motion Blur, LED Backlight.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. Keywords: field sequential color, liquid crystal display, color breakup, color filterless, Motion Blur, LED Backlight.

71.2: Gray Level Redistribution in Field Sequential Color LCD Technique for Color Breakup Reduction

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.

11.3: Mixed Color Sequential Technique for High Contrast LCD with Optimum Power Consumption

This paper proposes a mixed color sequential (MCS) algorithm with high contrast enhancement technique in RGB LED backlight display. Owing to synchronous control of LCD and LED panels, high quality image with suppressed color breakup and motion blur effects is achieved by our novel color sequential technique. Furthermore, high contrast image is also presented in LCD panel because of mixed RGB and CMY backlights with optimum power consumption. In other words, MCS algorithm with high contrast enhancement technique can have the better performance compared with other field sequential color techniques.

Spatial-temporal division in field sequential color technique for color filterless LCD

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. Keywords: field sequential color, liquid crystal display, color breakup, color filterless, Motion Blur, LED Backlight.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. Keywords: field sequential color, liquid crystal display, color breakup, color filterless, Motion Blur, LED Backlight.

Multi‐color LC/BL algorithm in field‐sequential‐color LCD for color‐breakup suppression

— The proposed liquid-crystal and backlight (LC/BL) algorithm presents the dynamic field-sequential-color (D-FSC) algorithm to reduce the color-breakup (CBU) effect without greatly increasing the subframe rate. The D-FSC algorithm can intelligently select one adequate color sequence from multiple color sequences according to the image data. In other words, the scope of CBU suppression of the proposed LC/BL algorithm is more extensive than other conventional FSCs. Simulation results show that the CBU suppression can be improved substantially by the proposed evaluation equation.

Pseudo Zero-Dimension Dimming for Power Reduction in Field Sequential Color Liquid Crystal Display Systems

Expensive hardware is required by the conventional two-dimensional (2-D) light-emitting diode (LED) dimming technique to obtain high-contrast and low-power in the field sequential color (FSC) technique. Thus, based on real-time image data, the pseudo zero-dimension (0-D) LED dimming technique is proposed to further reduce power dissipation in the D-FSC technique, which allows the intelligent selection of an adequate color sequence. The multi-liquid crystal and backlight (LC/BL) algorithm utilizes the D-FSC technique in temporal and spatial domains. It not only utilizes the pseudo 0-D technique to effectively reduce the color breakup (CBU) effect without greatly increasing frame rate, but also to reduce power consumption. On the backlight module, CBU suppression can be substantially improved and power dissipation can be reduced by at least 12.5%. Power consumption can also be further reduced through the re-dimming improvement in the proposed pseudo 0-D dimming technique.

AMOLED panel driven by time‐multiplexed clamped inverter circuit to reduce complex control signals

— A time-multiplexing technique employing a pulse-width-modulation (PWM) charge-pump scheme for driving active-matrix organic light-emitting-diodes (AMOLEDs) is described. This scheme greatly reduces the number of control lines. The two- or four-phase PWM driving technique not only reduces costs through the simplification of manufacture but also improves the uniformity and lifetime of OLED panels. Experimental results show that the proposed circuit effectively and precisely controls the timing of OLED data-writing and light emission.