Color-Sequential LED Driving System and Corresponding Color Saturation Analysis

• Main Authors: Ching-Hui Chou, 周清輝
• Other Authors: Jung-Hua Chou
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/08460752995800269193

碩士 === 國立成功大學 === 工程科學系專班 === 97 === The thesis focuses on color sequential driving technique. In this study, we use red, green, and blue light emitting diodes (LEDs) as the light sources of an LCD backlight. We accomplish this technique by using a computer-controlled interface to control the LCD backlight via signals from the LCD panel. LED backlighting with color-sequential driving technique has many attractive advantages such as high color reproduction, low driving voltage, fast response and mercury free, etc. The most attractive one is the possibility to remove color filters (CF) which can enhance the light transmission from the LCD with a high color rendering. So, this technique plays an important role in LCD industry due to the possibility of realize low power consumption, vivid rendering, and fast response display. Analysis of electric, optical, and color properties of the LCD with this technique is conducted. For the driving circuit, we compare different DC driving systems and suggest a better one. The mechanism of feedback and dimming of light is by using the scheme of pulse width modulation (PWM) of the current. This is more suitable for the LCD backlighting with LEDs as the light source. Finally, we examine the color shift of the LED backlighting and minimize the color shift by proper thermal dissipation treatment.