Analysis and Design of the Opto-Mechatronics Integrated Driving System for Light Emitting Diode Display

• Main Authors: Tsung Yu Wang, 王宗裕
• Other Authors: J. D. Lee
• Format: Others
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/44644825119393673775

博士 === 長庚大學 === 電機工程學研究所 === 96 === Recently, technique of display with light emitting diode (LED) has been widely applied in outdoor display wall. Usually, since the passive-driving method is applied to display for cost saving, some problems such as image defect occur. Therefore, how to improve quality of image by solving the problems in brightness uniformity is one of the main topics of display technique. In this dissertation, two applications in opto-mechatronics of LED display are proposed. One is two-dimensional LED array display and another is a projector system with one-dimensional LED array. Different from conventional structures solving problems about brightness uniformity by Scalar CHIP, an equivelent circuit model of a display is established to investigate the associated problems. Also, current-based compensation is then utilized to control LEDs in a LED array display. The LED array display can thereby provide a uniform brightness. Moreover, a compensation strategy is also proposed to effectively evaluate the brightness uniformity promoted by the proposed driver circuit for two-dimensional LED array display. In order to implement circuits for two-dimensional LED array display, a mono LED array display and a full color LED array display are investigated. Another topic is the application for the projector system with one-dimensional LED array. Different from the convnetional two-dimensional LED array display, the projector system is composed of one line of LEDs (bar LEDs), a lens and a rotational mechanism. They are provided to project an image emitted by the LEDs upon a screen. Therefore, by arranging lines in order, a two-dimensional image can be completely formed on the screen. Conventionally, the application for two-dimensional LED array display has LEDs to be arranged in two dimensions. The number of required LEDs of the structure for projector system with one-dimensional LED array can be smaller, which can effectively simplify the maintenance of the LED display. Furthermore, since the application for projecting system with one-dimensional LED array involves fields such as optics, machinery and driving circuit, it is hard to establish an exact model for imaging analysis. Hence, how to adjust parameters for a multi-physics problem to perform an optimal image magnification is another topic discussed in this dissertation. To achieve an optimal design to provide desired image magnification, Taguchi method and response surface method are used in this dissertation. It is convinced that the investigation and discussion in this dissertation is very helpful to the associated display technology.