The Research Of Nano-diamond Coating FED Power Source And Driving Control System

Field Emission Display (FED) is a novel self-luminous flat panel display. It almost contains all the advantages of cathode ray tube display (CRT) and other flat panel display, thus it is of great application foreground. Nowadays, it has become a hot study field. The current research mainly focuses on the cathode material, but the rapid development of FED industries can not be separated from the supporting of driving circuit. Lagging behind of the driving circuit would constrain the process of industrialization FED.In this paper is based on the study of Nano-diamond field emission cathode, takes the 4 Inch Nano-Diamond Coatings FED display as the goal. After detailed anglicizing of different types of power supplies and circuit topologies combined with the performance parameters of the cathode, we select a fly-back switching power supply as a FED special-purpose power source, and design a 32*32 lattice of nano-diamond coating FED driving circuit.The switching power supply take PWM UC3842 device as the core, including EMI filter circuit, input rectifier filter circuit, fly-back transformer, RCD buffer circuit, over-current protection circuit, the feedback voltage-stabilizer circuit, PWM control circuit and output rectifier filter circuit. During the design process, theoretical calculation and software simulation are combined to determine the required circuit parameters in order to select components. Our anticipated target is to achieve the expected 5V/500mA, 15V/500mA and 2000V/15mA three way output. Finally power circuit schematic diagram of the simulation and hardware debugging welding results are given, the results of the basic design are in accordance with the expected line.The driving circuit takes AT89S51 as the core, includes the core control unit, the row and line addressable units, the electro-optical coupler isolation unit and the level translators unit. The analyzing of the function and the implementation methods of each module takes integrate data-driven HV632PG and 74HC154 as the core to design the PWM and the scanning circuit; takes Half-Bridge Driver IC IR2235 as the core to design level-shifting circuit; takes electro-optical coupler isolation TLP521-4 as the core to design high-low-voltage isolation circuit. Finally we give a complete physical hardware driving circuit. The driving circuit output voltage is up to 2000V, able to achieve 256 gray levels of modulation, and can achieve a simple character graphics and dynamic display.For the function of the driving circuit, we use assembly language to prepare the corresponding procedures, compile and debug at KeilμVision environment, and download the software to MCU by XLISP. Finally the character dynamic scanning demonstration effect on the LED display monitor is confirmed...