Hitachi DX07

The Hitachi DX07 is a 2.9 inch (73 mm) liquid crystal display screen which went into mass production in December 2006:
Each pixel is therefore 78µm x 77µm (1µm = 1/1000mm).
Note: It's also safe to assume that this is an 8-bit per channel display (a 6-bit per channel display can only dither 1.62 million colours)
Optical Properties of the DX07.
The DX07 has a number of interesting properties related to its small size and high resolution. The following are true for someone with "normal" vision using this screen as a hand held device:
Notes:
Smallest Visible Pixel Size for a Hand Held Device.
The smallest visible pixel size ("p") for a hand held device can be calculated assuming the screen is held at a comfortable distance (250mm) for someone with "normal" vision (able to see detail at a 1/60 degree angle):
It can therefore be concluded that the pixel size for the Hitachi DX07 screen is only 5% greater than the smallest possible for practical use.
Note: Smaller pixel sizes would dither in much the same way as printed dots (72.7µm is approximately 350dpi)
Other Hand Held Screen Sizes.
If other hand held devices were manufactured for the latest high-definition video screen, then their smallest sizes without loss of detail (i.e. 72.7µm pixels) would be as follows: