Current outlook on FED monitors

[eric.kjellen]

The latest news on the FED (field emission display) technology seems to be a report in November 2010 that AU Optronics (that bought out the Sony FED venture and technology in January 2010) are expecting to mass produce panels by Q4 2011 while AUO themselves denied having gotten far enough in their research to consider volume production. These panels would be for "broadcast and medical purposes mainly". This, as is safe to assume, would place them out of reach for most consumer and enthusiast buyers. http://www.digitimes.com/news/a20101117PD210.html

According to some sources on the internet the main hurdle for the production of FED panels (at least as far as Sony is concerned) has been the lack of a production line, after Sony failed to acquire a former Pioneer plasma production facility for their FED monitors. Hopefully this is something that the AUO buyout will change and a production line something they feel they can bring to the table.

Other sources claim that patent issues have thus far prevented the FED from being made, even others that they are still impossible to produce because of technical hurdles of making the high vacuums that are needed and preventing the release of gas into the nanotubes during operation. I hope there are knowledgable people on this forum who could clear this up. There must be something that makes AUO think they can still bring out an FED panel and succeed in what Sony failed to do.

I prefer the warm, natural look of phosphor (both CRTs and plasmas over LCDs) and the fast response of CRTs so I hope that these difficulties are eventually overcome.

A couple of issues I would like to discuss:

Native resolution - As I understand it an FED will have one nanotube emitter for every subpixel, but I have also read that dead pixels will not be a problem with these displays because many of these emitters can power the same sub-pixel. According to Wikipedia: "Just like any other displays with individually addressable sub-pixels, FED displays can potentially suffer from manufacturing problems that will result in dead pixels. However, the emitters are so small that many "guns" can power a sub-pixel, the screen can be examined for dead emitters and brightness corrected by increasing the pulse width to make up for the loss through increased emissions from the other emitters feeding the same pixel" Will this also mean that they are capable of natively displaying several different resolutions?

According to this page, the nano-Spindt FED developed by Sony (that AUO took over) would have more than 10,000 emitters per pixel: http://www.fe-tech.co.jp/en/whatsFED/whatsFED.html

Resolution - Is the projected initial use of these displays for medical purposes reason enough to believe that they will start off with high resolution panels? The prototype shown here has 1280x960 pixels with a 0.306 mm pitch, and it would seem likely that some progress has been made since then.

 

[eric.kjellen]

About the native resolution part: Through a Beyond3D thread I found a part of a Sony patent where it is described how their FEDs would be able to not only operate on a fixed native resolution, as each half of two adjacent "sub-pixel fields" in the emitter grid would work together to light the area in between two designated "sub-pixels" (or really dots) on the phosphor surface as I understand it.

FIG. 12C illustrates another embodiment of a driving technique, which enables cathode half-pixel addressing similar to that of a CRT using an aperture grill. In this 45 embodiment, a positive voltage is applied to the gate wire 1206 relative to the grounded emitter line 406. Additionally, a negative voltage is applied to gate wires 1204 and 1208 with respect to the grounded emitter line 406. This generates an electric field that causes electrons to be emitted from 50 approximately half of cathode sub-pixel region 1212 and approximately half of cathode sub-pixel region 1214, which is labeled as cathode half-pixel region 1216. Advantageously, this appears as though an anode sub-pixel region (a dot) in between two previously defined anode 55 sub-pixel regions (two dots) of the phosphor line is illuminated. As such, an anode half-pixel region is defined as a portion of a phosphor line occupying portions of two adjacent anode sub-pixel regions. This is illustrated in FIG. 12F. This creates the appearance of a greater resolution than is 60 physically there, or in other words, creates a pseudo resolution. For example, by applying half-pixel addressing and varying the intensity level of the electron emission, an FED is created which appears to have much greater resolution that it actually has. Thus, such an FED will have a higher 65 clarity than a fixed pixel conventional FED. Therefore, analog-like performance is created since the designer can obtain a variable resolution on a fixed pixel display. This is a departure from known FEDs, which provide fixed performance in resolution due to the fixed number of cathode sub-pixels (i.e., the fixed number of electron emitters 112 or emitter cones of FIGS. 1-3). This half-pixel addressing is similar to half pixel addressing techniques performed in CRT type devices employing an aperture grill design. Such an example of a conventional CRT including an aperture grill includes TRINITRON CRTs produced and commercially available from the Sony Electronics Inc., of Park Ridge, N.J. USA.

Apparently this is a variation on the same technique that would be used for rectifying dead pixels, i.e. modifying which parts of the phosphor surface are targeted by the emitters and "varying field intensity" accordingly to compensate for lost brightness. This would mean, I take it, that even though FED monitors are technically known as fixed-pixel displays there would be no need for vile scalers to display different resolutions and that they would have a smooth, CRT-like look about them. I like them more already.

 

[mnewsham]

About the native resolution part: Through a Beyond3D thread I found a part of a Sony patent where it is described how their FEDs would be able to not only operate on a fixed native resolution, as each half of two adjacent "sub-pixel fields" in the emitter grid would work together to light the area in between two designated "sub-pixels" (or really dots) on the phosphor surface as I understand it.

Apparently this is a variation on the same technique that would be used for rectifying dead pixels, i.e. modifying which parts of the phosphor surface are targeted by the emitters and "varying field intensity" accordingly to compensate for lost brightness. This would mean, I take it, that even though FED monitors are technically known as fixed-pixel displays there would be no need for vile scalers to display different resolutions and that they would have a smooth, CRT-like look about them. I like them more already.

Sadly we are unlikely to see them in mass production. At least in the next decade.

 

[blanketyblank]

Don't mean to threadcap, but aren't there a lot of display technologies that haven't seen real production yet. I haven't seen any decent sized OLED and SED panels being sold for a reasonable price, and the technology has been touted for a while now.
I'm also a bit dissapointed in current LED backlit LCDs since I was hoping they'd actually use RGB LEDs instead of just replacing the fluorescent with white LEDs.

Considering how all those things went, I don't think FED is ever going to go consumer.

 

[eric.kjellen]

I'm pretty sure there are some RGB LED displays out there. A few Dell notebooks have them that I know of.

SED is now abandoned as a display technology (though FED is more or less the same) but OLED in computer displays is still being actively worked on.