An 852 x 600 pixel OLED-on-silicon color microdisplay using CMOS subthreshold-voltage-scaling current drivers

An 852x600x3-pixel, organic light-emitting diode (OLED)-on-silicon, color microdisplay utilizing a subthreshold-voltage-scaling method is presented. The pixel current is modulated between 250 pA and 25 nA. With a pixel pitch of 5 x 15 mum(2), the display contains 1.5 million individually address-able pixels sampling video signals at a maximum rate of 56.25 MHz, supports 15 video modes, and displays as many as 16 million colors. The 16.28 x 14.2 mm(2) monolithic display is implemented in a commercially available, 0.35-mum, single-poly four-metal 3.3 V/4.0 V CMOS process with the 10 million transistor system consuming 300 mW for PC applications. The SVGA+ active matrix OLED system provides a complete, integrated, analog interface microdisplay solution with minimal external components. DC-coupled RGB inputs with separate external vertical and horizontal synchronization inputs are accepted in accordance with the VESA VSIS standard. A fourth analog input is provided for composite monochrome, compatible with the SMPTE-170 standard. Also, unlike other OLED active matrix displays with digital on-and-off control and no gray shade rendering, gray shades are successfully achieved by continuously modulating the current density of each pixel.