The addition of in-cell touch technology has improved the display of the
iPhone 5, but it still lags the Galaxy S III smartphone from chief rival
Samsung when it comes to screen thinness and color gamut, according to
research firm IHS.
The iPhone 5's display is just 1.5mm thick, a 0.6mm reduction from 2.1mm for
the iPhone 4S, said IHS. Meanwhile, the color gamut of the iPhone 5 has
risen to 72% of the NTSC standard, compared to 50% for the 4S. Even so, this
falls short of the Samsung's flagship Galaxy S III, which sports a display
with a thickness of just 1.1mm and a color gamut with full 100% NTSC.
"As the first product with in-cell touch, the iPhone 5 represents a major
achievement, improving the image quality and reducing the thickness of the
smartphone compared to previous models," said Vinita Jakhanwal, director for
small- and medium-size displays at IHS. "And although the iPhone 5 still
trails the Galaxy S III in the display specs race, the iPhone 5 overall
remains thinner than the Galaxy S III, and its display color gamut is more
than sufficient for most users."
In-cell slimming
In-cell technology eliminates the standalone touch panel layers used in most
smartphones and instead integrates the touch sensors into the liquid
crystal of the LCD stack, sharing common electrodes and transistors. The
technology can reduce display module thickness by about 0.5mm on average,
reducing total smartphone thickness.
The iPhone 5 is 18% thinner than the 4S, at a total of 7.6mm. While the
display is thicker than for the Samsung Galaxy III, the iPhone 5 as a whole
is 1mm thinner than the Galaxy S III, which measures 8.6mm in total. The
Galaxy S III's greater girth is due to other factors separate from the
display, most likely the thickness of the battery.
Lighten up
Beyond thinning the display, in-cell's elimination of the separate touch
overlay layer allows more light to emit from the display without the
intrusion of added refraction and glare of the additional touch layers.
The iPhone 5's display still falls short of the NTSC color gamut mark
achieved by the Galaxy III. However, from a user's perspective, the lower
color gamut measurement may not necessarily make the iPhone 5 display look
worse than the Galaxy III. More accurate and realistic representation of
image color and contrasts may be a result of better calibration, higher
brightness and superior power efficiency of the display.
"Some user reviews indicate that colors presented on the Galaxy S III
actually can look oversaturated and unrealistic," Jakhanwal said. "While it
may be interesting to compare the display specifications for the two phones,
the actual front-of-screen viewing experience could diverge for different
users."
Display power issues
The Galaxy III employs an AMOLED display, in contrast to the low temperature
polysilicon (LTPS) LCD employed in the iPhone 5.
As AMOLEDs do not use a backlight unit, they potentially have better power
efficiency than LCDs. However, there are concerns about differential aging
of organic materials, which affects OLED lifetime and power efficiency. And
although display power consumption is important, overall battery life of the
device will still be dependent on many other factors.