Low-Power Drive Method for MIM-Cathode Displays

摘要

A low-power drive method for reducing dissipation power by 75% is developed for cathodoluminescence displays using metal–insulator–metal (MIM) cathodes. The dissipation power is the power consumed in driver circuits for charging and discharging capacitive loads of a display panel. The drive method, called high-impedance (high-Z) drive method, reduces the panel's effective capacitance by connecting non-selected scan lines to high-impedance driver outputs. No visual crosstalk occurred in displayed images on a 3.8-cm-diagonal MIM-cathode display, regardless of significant induced voltages observed on the high-impedance scan lines. This insensitivity to the induced voltages is mainly because the polarity of induced voltages is reverse for electron emission. To reduce the induced voltage, an “enhanced high-Z drive method” is also developed. Analytical formulae to calculate the dissipation power and the amplitude of the induced voltages are devised on the basis of a capacitor model of the MIM-cathode array. Excellent agreement between measured and calculated results validates this model. On the basis of the capacitor model, the total power consumption of a 32-inch diagonal MIM-cathode display is estimated. This estimation indicates the total power consumption would be only 24 W including dissipation power at an average brightness of 200 ${hbox{cd/m}}^{2}$.