Improved gray‐scale monochrome and color AMEL displays using analog pixel

Abstract

Abstract— Active‐matrix electroluminescent (AMEL) microdisplays have been known for their numerous beneficial characteristics such as low weight, compactness, high brightness, and high contrast ratio. Beside these desirable characteristics, some of their drawbacks include difficulty in obtaining a high number of gray‐scale levels or a large number of colors, and interface‐electronics complexity. To address these drawbacks, AMEL displays using an analog addressing architecture have been developed. Utilizing this new driving scheme, 256 monochrome levels or 16 million colors are obtainable. Gray shade is proportional to an analog voltage stored on the hold node of each pixel. For color displays, each pixel is comprised of red, green, and blue subpixels arranged in vertical stripes, and can be sized independently to achieve the appropriate white balance. With the integration of control‐signal circuit blocks on the same substrate as the microdisplay, the number of input control signals is minimized and the display can be driven with very simple interface electronics. This results in low overall system cost, compact electronic packaging, and low power consumption. To accommodate most optical orientations, the display has built‐in modes to flip the image both vertically and horizontally. Additionally, the display supports multiple interlace addressing modes.