Toshiba developing LCDs using field sequential tech
By Donald Melanson 
posted May 25th 2006 1:56PM
posted May 25th 2006 1:56PM
This one seems to have gone under our and most other people's rader, but Toshiba is trying to signficantly bump up LCD performance with a new 9-inch TFT that promises the world's highest level of transmittence, as well as wide viewing angles and high speed response. What makes this display unique is the combination of optically compensated bend (OCB) and field-sequential technologies. Unlike traditional LCDs, field sequential technology does not require color filters, which can absorb up to 70% of backlight brightness. It also doesn't subdivide each pixel like the color filter method does, resulting in three times the potential resolution of a traditional LCD. Better performance and higher resolution sounds good, but is brightness really a problem for LCDs? If our Dell widescreens were 70% brighter we think we'd probably all be suffering severely burnt retinas -- happily so.
If it absorbs less backlight, you can probably lower the brightness of the backlight and use less energy so your battery will last longer.
So If I understand what your saying... There are no black scanlines? It all smudges together into perfect harmony?
If so, I want one in replacement of this bulky monitor thx! :P
WTF is rader?
like, what [1] said, and stuff.
Samsung actually showed a 32" field sequential color LCD at FPD International in Yokohama in Oct 2006. This is cool technology, but nowhere near commercialization.
do they have a prototype or still in papers?
Yes, brightness IS a problem for LCD screens.
For example, with such technologies that also increase resolution, small e.g 3" High Definition LCDs can replace the optical viewfinder on DSLRs (pro digital cameras) and show 10times more information about the actual photograph before capture. And with such brightness you'd be able to see it easily under direct sunlight.
Also a number of additional outdoor monitors or even advertisement panels could be made.
For other applications not requiring more brightness,
probably there will be the energy economy advantage.
How do they do the color changing for the backlight? Is there a moving element? It would be cool if it used LED backlighting with three different colors turned on and off. The pixels would have to have three times the response time, maybe 2-3ms to prevent bleeding and ghosting. You might also have to turn off the backlight completely for a moment during the shift which would reduce the apparent brightness.
P.S. It's interesting how we've come full circle on mechanical color displays. Original color TVs had a color wheel scheme which was abandoned, and is back in use with DLP, and from what I've found in the last few minutes, the color changing for these displays is done by a shifting lens.
Lowering the brightness of the backlight not only decreases power consumption and increases battery life, but also lowers the black level and gives more detail to dark scenes.
Its like a color wheel. So you will get rainbows just like on a DLP. But the refresh rate is lower on LCDs so more people will be able to see it.
Re: #11
DLP has a effective response time of about 8ms. The article says that the LCD panel has a 3.3ms response time. Typical LCDs are in the 12-20 range. Current high end LCDs like the Sony Bravia have an 8ms response time.
The 8 ms response time of a DLP is very different. The individual switches are full on or off, so it PWMs with a very high repetition rate to generate a gray scale. 8 bit color would require it to switch at a rate of 2.66ms/256 or about 10uS switching time. The gray scale is then sent throught the color wheel which is spinning at some rate which i think updates the colors 2x per frame (16ms response is needed for 60p video) Now with an lcd with a 3.3mS response time it would settle to the color then the backlight would change color, then the grayscale of the lcd would update again, and so on. So it would take 9.9mS to generate white (RGB cycled). And it takes only 8mS to generate white (RGB cycled on a DLP). The fact that the RGB cycling is switching slower on the LCD means color breakup or the rainbow affect would be easier to see. The new samsung dlps with LEDs instead of a color wheel switch through the colors about 20x faster making it not possible to see color breakup giving the DLP a response time of about .4mS to generate White. I think this is how it works.
If your 30" Dell was 70% brighter, it would still only be 51% as bright as one without a color filter. (Assuming the color filter is absorbing 70% of the brightness.)
C'mon, I can't be the only math nerd that caught that!
Also notice the lack of subpixels - ClearType isn't gonna work as well on this as on a normal LCD. But I'd rather have higher resolution, anyway.