AM-TFT LED tiled spherical display for flight simulators

The proposed approach focuses on employing an active-matrix-thin-film-transistor (AM-TFT) back plane-based LED display technology to meet/exceed the primary objective of increasing the targeted ANSI contrast ratio. The storage capacitor in AM-TFT circuit design stores next image frame data and can be completely turned off to create ultimate black level. This is a significant advantage over legacy passive-matrix LED driver where the LEDs are always on for the display to function properly. Since the EIS is also a spherical display, a trapezoidal tiled approach is proposed to create curved surface. The tiled design also allows for aspherical structure by changing the vertical and horizontal radius. Dome type structure can be achieved by adding tiles to the existing design both vertical and horizontal direction. Glass-based AM-TFT back plane substrate allow much higher precision tile size control over PCB-based back plane. In order to seamlessly connect AM-TFT LED glass tiles, a proprietary through-glass-via (TGV) design will be used to relocate the driver I/O traditionally mounted on the side of the tile to the back of the glass substrate. The TGVs are made conductive to electrically connect the LED pixels and the drivers located on the other side of the glass substrate. In Phase I, a spherical LED display demo unit will be built as a building block that allows extension to a full 180o/60 o horizontal/vertical FOV. A 940nm infrared LED can be added to the pixel to demonstrate NVG compatibility without interfering the RGB color performance (Phase II). The demo unit consists of 16 trapezoidal glass tiles (approximately 100mm x100mm) with pixel pitch of 1.53mm and a radius of 1.5m. The demo unit forms the building block to create horizontal arc. Multiple of such building blocks will be assembled to demonstrate meeting the FOV in both directions. In Phase II, a full AM-TFT spherical LED display will be built with specification meet or exceed the target specification.