Raytheon FED technology update

The field emission display (FED) delivers all the advantages of the cathode ray tube (CRT) without the disadvantages. The FED presents the viewer with an unrestricted viewing angle, full-motion video bandwidth, wide operating (-54°C to +95°C) and storage (-62°C to +115°C) temperatures, and "instant on" anywhere in the operating temperature range. The FED does not have the CRT disadvantages of center to edge spot size variations, astigmatism, geometrical position errors, linear distortion, and misconvergence. Additional FED advantages include shallow package depth, fewer process steps than AMLCD, potential lower cost than AMLCD, 1000 times less peak anode current per pixel (FED turns on one row at a time) and inherent shock and vibration resistance provided by low mass internal elements. (See Figure 1 - Field Emission Display is a Flat CRT) Raytheon CRT products are currently installed in high performance military and commercial systems. These platforms include fixed wing aircraft: F-14, F-15, F-16, F/A-18, S-3A, B-1B, JAS-39, Tornado, EF-1 1 1 and B-52; rotary wing vehicles as Apache AH-64D and EH-1O1; shipboard applications SPA-25G and CCS-MKII Los Angeles class submarine fire control system; world-wide air traffic control programs as Canadian RAMP, OIDT, and in some of the other nineteen countries installing Raytheon air traffic control products. FED high power screen efficiency in a monochrome display can exceed 25 lumens per watt and 1 5 lumens per watt in full color applications. Average power dissipation is determined by the higher duty cycle of video content. The 8KV anode of the Raytheon FED yields the highest brightness of any flat panel display at 300 IL to 400 fL after 10% contrast filtering in a 10,000 fc ambient environment. "Instant on" full brightness is achieved within five seconds within the -54°C to +95°C operating range without heaters, ITO layers, anti-freeze or preheating or pre-cooling. The FED full viewing angle of 1600 x 1600 is usable in portrait or landscape mode. Display electronics adjust from full brightness down to 0.01 fL for night vision (NI/IS) equipment. Gray scale levels of 0 to 256 shades of gray are provided by 8-BIT drivers operated through a pulse width modulation scheme allowing peak anode current to be large enough to remain in the linear portion of the transfer function. Full motion video speed results from phosphors which span the entire decay envelope of <0. 1 msec for extremely fast flying spot scanners to long persistence <50 msec for PPI radar. True TV colors in any gamut, hue, saturation or Snell diagram location are available from conventional phosphors or mixtures. FED aging is the result of a gradual reduction in phosphor efficiency. Each pixel is served by approximately 400 microtips. Random failures of as many as 10% of the microtips is undetectable to the eye. The focus assembly provides electron beam focusing and high voltage arc suppression, shunting intercepted arcs from the anode to ground to prevent cathode damage. The inherent simplicity and robustness of the FED design demands only small construction differences between commercial and military designs. (See Figure 2 - Raytheon's 4 Inch Square Field Emission Display) An exploded view of the four inch square FED monitor is shown in Figure 2. The base and the housing bolt together to enclose the FED. The contrast enhancement filter is optically bonded to the front glass anode panel with an index matching epoxy.