Opinions, Observations and Ramblings about media technology.

Monday, March 4, 2013

4KTV: Calculating Megapixels per Kilobuck

It’s been about ten months since the new Ultra High Definition television standard was announced by the ITU-R.   The press release explained that “UHDTV is an earth-shaking development in the world of television”.   The committee chair that completed the work is my buddy David Wood, who was quoted as saying “Some years will pass before we see these systems in our homes, but come they will.”  Of course, David’s right.  But how many years? ...and what exactly are we waiting for?
Already, UHDTV sets are being sold by Sony and others.  The first products to hit the market are large (84-inch) and expensive ($20k to $38k).   The picture quality can be amazing, but at that price, Ultra HD isn’t on my wish list yet, even if I could fit one in the house.   Smaller, and presumably less expensive sets were shown at CES in January, and are expected to start shipping next month.   Sony will have 55-inch and 65-inch models available.   

Sony's recently announced XBR-55X900A and XBR-65X900A are scheduled to ship in April 2013.

Respected pundit Pete Putnum recently observed that some Taiwanese and Chinese manufacturers (Westinghouse, Hisense, and TCL) are already floating aggressive prices on 4K TVs; about $50 – $60 per diagonal inch in sizes up to 65 inches.  I'll save you the math -- that's less than $3,300 for a 55-inch model, or a half-penny per dozen pixels, if you're counting.  Ultra HD sets have not only come to market quickly, but it appears the same price wars that have pummelled the HDTV business are already migrated to UHDTV.

Remarkable developments -- and investment -- in display technology are contributing to these rapid price declines.  Consider the pixel density require for Ultra HD displays.  The UHDTV-1 standard calls for four times the resolution of HD, which comes to 3,840 x 2,160.   Applying Pythagoras' theorem, we can figure out that in a 55-inch diagonal panel, the screen width is 48 inches.  Fitting 3,840 pixels in 48 linear inches requires a pixel pitch of 317 micrometers, or 80 pixels per inch (ppi).

That sounds pretty impressive until you realize that the iPhone 5 display is four times higher pixel density, at 326 ppi.  With charactoristic hubris, Apple claims "The pixel density is so high that the human eye is unable to distinguish individual pixels."  That’s arguable.  But the new HTC One phone even beats that, with 468 ppi display supporting full 1920 x 1080 high definition on a 4.7-inch display.  Still not impressed?  How about these glasses, which display 1920 x 1080 on a 0.74-inch panel.  That works out to nearly 3,000 ppi – over 40 times the pixel density of the fancy new 55-inch Ultra HD set.   But that's not the limit -- Sony has released a 4K projector with 0.74 LCOS (Liquid Crystal on Silicon) panels, with an amazing 6,257 pixels per inch.    Perhaps this sheds some light on the further progress to be expected in LCD panel developments.
The 4K Sony VPL-GT100 has three 0.74 inch
LCOS panels with 4 micrometer pixel pitch
 So if UHDTV televisions are available, and will be affordable before long, what can go wrong?   Let me think about that, and get back to you...

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