This paper presents an examination of the requirements for observer tracking autostereoscopic 3D display systems. The optical requirements for the imaging of autostereoscopic viewing windows in order to maintain high image quality over a large range of observer positions are described. A number of novel displays based on LCD (liquid crystal display) technology have been developed and demonstrated at Sharp Laboratories of Europe Ltd (SLE). This includes an electronically switchable illuminator for the macro-optic twin-LCD display; and a compact micro-optic twin-LCD display which maintains image quality while extending display size and viewing freedom. Work has also been in progress with flat panel displays to improve window quality using a new arrangement of LCD pixels. This has led to a new means to track such a display with no moving parts.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.