A new normally black high-contrast wide symmetrical viewing angle AMLCD for military head-mounted displays (HMDs) and other viewer applications

摘要

Kopin's miniature Active Matrix Liquid Crystal Displays (AMLCD's) are used in military head mounted and sensor viewer applications. These low power, ruggedized displays operate from -37°C to +65°C with excellent imaging characteristics and reliability. Kopin and the US Army Night Vision and Electronic Sensors Directorate (NVESD) are developing high resolution, full-color displays for day/night operations and image fusion applications. Kopin has begun the development of a miniature, spatial color SXGA display using a new Kopin design and process to fabricate multi-domain vertical alignment (MVA displays. The MVA display offers a normally black screen, very high contrast ratio and wide, symmetrical viewing-angle. MVA monochrome SXGA, monochrome VGA (640x480 pixels) and color filter VGA displays have been demonstrated. A 0.97" diagonal, color filter SXGA MVA display is the goal for this program. The patented MVA process uses a simple fabrication process that makes use of the intrinsic fringe field in each pixel to control the LC alignment. Contrast ratios greater than 1000:1 and 120-degree symmetrical viewing angles are routinely achieved. The power-off state or failed state on MVA displays is black, which reduces the visibility of defective pixels. The normally black AMLCD is the preferred mode for night military operations / applications, and see-though Head Mounted Display (HMD) optical designs. Performance data and specifications for Kopin's monochrome and color filter MVA displays will be presented with reference to military (HMD and weapon sight), industrial, and commercial applications. Application extensions that utilize the new MVA color filter technologies developed will be highlighted.