iPhone 5 Rumors: Features May Include In-Cell Technology for a Thinner and Lighter Display

The Wall Street Journal just threw its weight behind some fairly old scuttlebutt that Apple’s new iPhone will employ thinner screen technology when it arrives, presumably later this summer or sometime in the fall. That technology is known as “in-cell,” referring to the location of the touch sensors themselves in the phone’s screen. The WSJsays the new screens are already being produced by Apple’s supply chain partners, including Sharp, Japan Display and LG.
Like most touchscreen devices, today’s iPhone uses technology in the touchscreen referred to as “on-cell,” where the touch sensors lay on top of the color filters, occupying a separate layer that adds a fractional amount of thickness to the design (just under 0.5 mm in the current iPhone).
In an “in-cell” configuration, by contrast, the touch sensors live inside the color filters, eliminating that extra layer and thinning the touchscreen interface through integration of the touch and image components.
Even a fractional increase or decrease in width can make a significant difference in the overall design aspirations of a device as small as a smartphone, especially when you’re calculating how much space each layer consumes in volumetric terms, say on a 3.5-inch diagonal screen (or, in the next iPhone, the rumored jump to a screen that’s four or more inches).
If the WSJ‘s “people familiar with the matter” are reliable and Apple is indeed shifting to “in-cell” display tech, here’s a breakdown of the benefits from both consumer and manufacturing standpoints.
A thinner iPhone. It goes without saying, but let’s walk through the dimensional specifics.
The original iPhone was 11.6 mm deep, grew to 12.3 mm with the 3G and 3GS, then shrank to 9.3 mm deep with the iPhone 4 and 4S. The “in-cell” shrink would probably shave off just under 0.5 mm, which isn’t much, but consider what KGI Securities analyst Ming Chi-Kuo suggested in an April note that Apple could be aiming to bring the next iPhone in at under 8 mm, in part by switching back to a metal (though probably not “liquid metal”) back face to replace the iPhone’s existing glass one. According to Kuo, the new back piece could shave as much as 1 mm off the total width, dropping the iPhone to just under 8 mm thickness.
If the latter turns out to be true, it could mean at least a 14% depth reduction from the current iPhone and a 31% reduction over the original model. Millimeter changes are almost indiscernible to the casual eye, but to the hand? I notice subtle spatial differences in objects like smartphones far better by touch than sight. And a thinner iPhone would mean thinner cases, too.
Improved screen imaging. The more layers light has to pass through to get to your eye, the less clear the image on the other side of those layers is going to be. Anyone who’s lived with a smartphone screen protector for a considerable period of time, then pulled it off to swap in a new one, has probably noticed how much sharper and clearer the display looks with the protector removed (even a razor-thin piece of plastic can negatively impact how crisp or clear text and images on a display look).
An “in-cell” display wouldn’t solve the screen protector issue, but it would eliminate a significant layer in the light-to-retina equation, theoretically improving the clarity of images and text with or without an optional aftermarket protective layer.
Reduced (or counterbalanced) weight. Thinner, if Apple adds nothing else, also means lighter, though the iPhone 4S already weighs next to nothing at just 4.9 ounces — about as much as a deck of cards. Chances are Apple will instead use any weight reduction gains to add or augment other components, or possibly just to offset weight added by the rumored larger screen.
All iPhones, from the first in 2007 to the 4S in 2011, have a 3.5-inch diagonal display area, but the new iPhone is said to be the first with a larger screen — at least four inches diagonally, possibly more. Apple’s under some pressure to move to a larger screen given what its rivals — Samsung chief among them — are doing with competing phones like the Galaxy S II (4.3 inch display) or the brand new Galaxy S III (4.8 inch display).
Yes, “nearly 5-inch” displays aren’t for everyone, but 3.5-inches feels almost constrained in a smartphone-verse of at least 4-inch displays. A 4-inch (or slightly more than) iPhone display would pull Apple out of the screen real estate basement and more than justify the slight weight gain.
More space for a larger battery. Today’s iPhone boasts up to eight hours of talk time on 3G, 14 hours on 2G, up to 200 hours of standby time, up to six hours of Internet use on 3G (up to nine on Wi-Fi), up to 10 hours of video playback and up to 40 hours of audio playback. The reality, of course, is wildly different, with many people seeing only a fraction of Apple’s idealistic projections.
Increasing the battery size to squeeze a few precious extra hours of talk time or app use — even if it offsets weight reduction gains in the design — would probably be a boon for consumers. I know I’d much prefer longer battery life than see the iPhone lose any more weight (in fact I’d gladly accept a net weight gain for better battery life at this point).
Faster, streamlined manufacturing (well, maybe). Analysts like Kuo have suggested that switching to “in-cell” technology would make Apple’s supply chain more efficient by mitigating potential “fail” points in the manufacturing process that have to do with layer-to-layer bonding and more than halving the number of days in production.
That said, the WSJ writes that “in-cell touch screens are harder to manufacture than conventional LCD screens,” and the paper’s sources claim that LCD manufacturers are having trouble ramping the new tech up to sufficiently high yield rates.
If manufacturers can come to terms with these new (unspecified) manufacturing challenges, it stands to reason Kuo’s point about layer-to-layer bonding time savings would apply, though whether we’d see this benefit by launch time, when demand usually outstrips supply, is anyone’s guess.