3. Angular Resolution
Obj 1 Obj 2
• “Resolution” is defined s
and measured by an
angle, not a distance.
• “Angular” resolution
can be converted to
“spatial” resolution r
such as 440 ppi. θ
r ⋅θ = s
human
4. Visual acuity
• 20/20 vision : see clearly at 20
feet what can be seen by a
person with normal vision at
that distance (20 feet far
away).
20/15 vision : see clearly at 20
feet what can be seen by a
person with normal vision at 15
feet (beyond normal vision).
• Normal vision : 1 arcmin (1/60 a
degree)
Perfect vision : 0.6 arcmin
(1/100 a degree)
5. “Retina” display is true ?
Apple Steve Jobs :
It turns out there’s a magic
number right around 300
pixels per inch, that when you
hold something around to 10
to 12 inches away from your
eyes, is the limit of the
human retina to differentiate
the pixels.
6. In the scientific view ..
For a person with perfect vision at 12 inches far away from the screen :
The retina resolution for them is 476 ppi !
1
= 476.19 ≈ 476
0 .6 π
12 × ×
60 180
For a person with normal vision at 12 inches far away from the screen :
The retina resolution for them is just 286 ppi.
1
= 286.48 ≈ 286
1 π
12 × ×
60 180
7. Beyond Apple’s Retina Display ?
LG Display :
Size : 5”
Resolution : 440 ppi
Toshiba :
Size : 6.1”
Resolution : 498 ppi
8. Vision ? Distance ?
3.5” iPhone 4 with 326 ppi => 12 inches (not achieved
retina resolution yet for some people with perfect
vision)
5” LGD with 440 ppi => longer than 12 inches for
normal use (retina resolution ? Depend on the
distance)
6.1” Toshiba with 498 ppi => much longer than 12
inches (beyond retina resolution, just technical
achievement, not practical)
9. Application of super high
resolution display ?
Some product with a
display very close to eyes,
like Google Project Glass ?
Issues :
• Transparency ?
• Small and light enough ?
(5”,6” larger is almost
impossible)
• Driving power ?
(So many pixels drain the
battery life)
