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The World's Smallest Full HD Display
An anonymous reader writes "Ever heard of Ortustech? Probably not. But you have heard of Casio, right? Ortustech is a joint venture between Casio Computer and Toppan Printing to develop small and medium sized displays. Today, the company is announcing a doozy with its 4.8-inch 1920 x 1080 pixel HAST (Hyper Amorphous Silicon TFT) LCD with 160-degree viewing angle, 16.8 million colors, and a pixel density of 458ppi. Amazing when you compare that to the lauded 326ppi of iPhone 4's Retina display."
I'm sure many will correct me if I'm wrong, but the basic gist of devices like the Retina display is to match or slightly exceed the theoretical limit of an eye's ability to resolve details at a normal usage distance. This is an argument directly related to the Nyquist theorem: to capture a signal, scan at a resolution at least twice your desired sensitivity. The Compact Disc chose 44050 Hz sampling rate because our ears generally cannot hear anything over 22000 Hz.
What the Nyquist theorem misses is that the mind is not just taking a single sample, but a time series of many samples. A good listener or an observant viewer can see qualitative differences in a square wave and a smoother sine wave, even near the limits of resolution. In the visual realm, there's a good example. As you move an image across different photoreceptors, the brain will synthesize additional resolution. Our eyeballs do this all the time: tiny involuntary movements called Nystagmus help our neural edge-detectors gather more data to aid in perception. You can experiment with this using a video editor and one of those "pixelating" filters: move an object behind a coarse pixelating filter, and you can easily determine more about the original object shape than you could with a fixed image. Nystagmus beats Nyquist, if you will.
I think there's plenty of room for higher resolution sampling: music is often sampled at 48000 KHz nowadays, and I think handheld displays will benefit from 400+ or even 500+ DPI easily.
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I am kind of busy. Can anyone please do the Apple bashing for me?
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It's the data rate that's a problem.
Let's imagine 458dpi on a relatively "modest" screen that's 20in by 11.7in. That makes a display resolution of 9160 by 5358.
To update that screen at 60 frames per second would require a data rate of 6.9 *terabits* per second to the actual panel. Now you can say, "compress the data before sending it to the screen", but that would just increase the processing power needed, and at the end of the day, something still has to feed the raw panel the data at 6.9 terabits per second.
Big screens aren't getting higher DPI because (a) it's not needed (generally, you're looking at a big screen from a few feet away, and 100 dpi is more than enough) and (b) it would be fantastically expensive to do it and (c) no one has developed a standard to shift data from the computer to the display at the kinds of data rates that would be required to drive such a display.
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The OS doesn't mention DPI, but it still "knows" it. For example, a font of a certain point-size is, by definition, a certain size in other units. If I correctly recall high-school typing class, 10 points is 10 characters per inch wide and 6 lines per inch high.
Changing to a larger monitor of the same resolution should cause the same point-size to display with fewer pixels, as each pixel is now bigger.
Windows and X11 both allow you to set your monitor's DPI so that this stuff looks right. OS/X has some variable DPI stuff in the back end, but Steve won't let them expose it because they can't get it working right.
I had an unbelievably annoying experience in this regard last year. My Mac Mini with a 1280x1024 17" screen was working fine, but I needed a faster box and wanted a bigger screen. I went out and bought a 28" iMac..... only to discover that while the screen size increased, the resolution increase outpaced the physical size of the screen -- the net effect was that the writing on many dialogue boxes etc was so small that I couldn't read it. (My eyes suck, sue me)
To add insult to injury, there is also no official way on Leopard to alter the system fonts (like "Large Fonts" in Windows). Fortunately, I found some 3rd party software out there on the 'net that let me tweak the right prefs, and I now have a readable display.
But the DPI is still wrong.
Incidentally, I asked around in a bunch of mac forums and IRC channel. You know what the popular answer is among the fanbois? "Lower your resolution".
WTF?! That's stupidest answer ever! Yes, it DOES make the fonts bigger (actually illustrating the problem), but Christ almighty, especially when we're talking LCDs, what a moronic suggestion!
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The spec sheet is for something different: instead of 4.8'' it is 2.4''; instead of 16.8M colors it displays 260k colors, and it is only 320x240 pixels (at 170 ppi). It appears to be a spec sheet for their previous announcement. I can't find anything about the current announcement on the Ortustech website...