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IBM Research Enables Flat-Panel CRTs
joescrooge writes: "IBM's got something new to give those LCDs a run for their money." That something new is CRT technology which removes the unsightly humps that take up most of the space of traditional monitors, and directing the electron beams through a magnetic panel about the size of the displayed image. Considering that 15" LCDs are now under $400 at Walmart, even cheaper ones sound like a pleasant fantasy for dual- and triple-headed flat-panel systems.
Electrons slamming to a stop produce X-rays. The faster the electrons and the faster the stop, the higher energy the X-rays. Color monitors have a lot of lead in the glass (several pounds of it) to keep your skull from developing a nice monitor burn :-)
-- Alastair
The biggest problem with LCDs is that of fixed resolutions. An LCD screen has a fixed number of pixels, so adjusting the screen resolution is difficult at best and hideously ugly at worst...
Hate to disappoint you, but I don't think these CRTs are going to be any different. These "tubes" accelerate electrons from a cathode the size of the entire screen through a grid of holes with magnets, one hole per pixel. These magnets then redirect the beam slightly, hitting either the red, green or blue phosphors in the front of the screen.
I'd imagine, though that monitors based on this technology would have *much* less flicker than conventional CRT monitors. Since there is essentially one beam per pixel, the speed at which one can accurately scan a single beam around the screen is no longer a limiting factor for refresh rate. The *only* factors should be the bandwidth between monitor and video card, and the latency of the phosphors in the screen.
"Intelligence is the ability to avoid doing work, yet getting the work done".
It's only software!
Well, the weight of the glass grows exponentially with size. Because the inside is a vaccuum, the glass has to hold quite a bit of pressure. As tubes get larger, the walls have to get thicker to maintain structural integrity. Combine that with increased surface area, and that's a lot of glass.
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A normal CRT uses an electromagnetic coil to direct the spray of electrons coming of the (relatively small) cathode at the back of the monitor. The lines of the screen are literally traced out by the stream. This puts hard limits on the requirements for a phosphor -- the phosphor has to be designed to be as bright as possible for the entire length of time it takes to refresh the whole screen, and then fades out as quickly as possible after that interval. This is a difficult requirement and one that can really only be approximated.
This screen, however, uses a large cathode and localized electromagnetic fields (one per pixel) to direct the beam. That means the screen is refreshing all over, all the time, instead of a line at a time. Phosphors for this new monitor, then, need not be designed to stay at full intensity for anywhere near as long as traditional CRT phosphors, which means that they can probably be made to improve the contrast significantly.
I'm no expert on this, so corrections are welcome... but as I understand it, the light0gun model and it's impact on phosphor choices has long been one of the biggest impediments in CRT improvement, and it sure looks to me like this design breaks that problem down very efficiently.
The New Scientist had an article about this back in May. They took a slightly different angle on it -- pointing out its "spy-proof" features. Although the article appears to be gone, Google still has a copy of it.
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Don't confuse the technology behind a CRT (The cathode generating an electron beam striking a phosphor) with the implementation (A single beam, steered across the screen by magnetic coils) of a standard CRT. This sounds remarkably similar to FED, ThinCRT, and other similar technologies. While the technology is the same (Cathode generating an electron beam striking a phospher) the implementation will likely be fastly different. In this case, it will be virtually identical to LCD - you have an address decoder that just walks through the horizontal and vertical rows, illuminating one pixel/row of pixels at a time, where each pixel is a defined area on the screen (Like LCDs) not where the beam happens to strike (Like traditional CRTs) In fact, the addressing hardware will probably be virtually identical. The biggest difference is instead of a transistor at each pixel, it just has an anode for the rows, and a cathode for the columns, and where the signals meet is illuminated. (Or vice versa) As to heat.. Most similar technologies use something called cold cathodes.. Due to their much reduced power requirements, they can use slightly different technologies, and do not require being warmed up like traditional CRTs before they operate. Of course, due to IBMs lack of information, this could all be wrong, but it is what it looks like to me. This should beat traditional CRTs for weight, power consumption, and clarity (No focus or convergence problems and simplified geometry management - push button alignment like on LCDs) but still use more power than LCDs and be heavier. I'm still keeping my eye on OLEDs though.
CRTs are great for cost/image resolution, but LCDs and OLED win on power consumption and temperature. This article was a bit light on details for the new IBM tech, but I doubt a CRT can rival LCD and OLED in these categories.
MacOS, Windows, BeOS, GNOME, KDE: they're all just Xerox copies