Abstract: Methods and apparatus are provided for equally aging a cathode ray tube (CRT). In the preferred embodiment, a standard CRT having a 4:3 aspect ratio is provided. An external video terminal is coupled to the CRT and receives any number of external video signals, one or more of which may be non-standard external video signals having a 16:9 aspect ratio. In response to a non-standard external video signal, the CRT is illuminated with a mismatched illumination ratio, i.e., a primary CRT region is illuminated and a secondary CRT region is not illuminated, resulting in an unequally aged CRT. A video pattern generator is coupled to the CRT and generates an internal video signal, such that the secondary CRT region is illuminated in response to the internal video signal.
Abstract: A projection television set having a screen and three projection units each capable of projecting a monochromatic image onto the screen. The projection units each having a cathode ray tube (CRT) optically coupled to a projection lens, which includes both a C-lens and a compound lens. A spacer preferably having three optical passageways is coupled to and between the CRTs and projection lenses such that three coolant chambers are formed. Preferably, the spacer includes fluid passageways that interconnect the coolant chambers. The spacer also include coolant fill ports and reservoirs, zero pressure gum tanks seated in the reservoirs, and a plurality of heat exchanging ribs.