A recently revealed Apple patent has been getting some attention on the InterWebs because it’s related to improved touchscreen tech, and everyone’s rushing in with a thin iSlate prediction. But the patent’s oh so much more than that.
To understand the tech behind Apple’s patent, let me quickly explain how existing touchscreen tech works. There are several types, but the one we’re interested in here is called “projected capacitance” and it’s the system that allows multitouch to work. Essentially a normal LCD screen is protected by a thin sheet of protective and electrically insulating glass. The glass is actually coated with a very thin layer of transparent electronics, based on chemicals like indium tin oxide, which are built up in layers similarly to how a silicon chip is made, then etched and covered in more transparent protective layers (like the iPhone 3G S’s oil-repellant layer, for fingerprint smudges.) The touch magic is in these transparent electronics: As your finger (which is naturally electrically conductive) approaches the touch layer, it influences the capacitance of the thousands of tiny transparent sensors. Other electronics calculate exactly where your finger is from this data, and pass that onto the device, and: Bingo! Touch-sensitive screen tech.
The system works very well, but Apple’s patent goes one step further. Whereas existing touchscreens are a complex sandwich of chemicals and electronics in the LCD, glass, transparent electronics, and protective layers, Apple’s bright idea is to do away with some of the layers. Why have such a complex system, when the electronics for touch detection could just as easily be built into the electronics that makes the LCD (or perhaps even OLED) work?
The number of benefits are impressive: It’s a simpler overall design, which could reduce costs. The touch tech is protected by the insulating glass, so its more structurally safe–and you could even swap glass for a toughened plastic perhaps. And then there’s the feature that lots of people have been quoting so far: The resulting display is thinner in depth, which could translate into a thinner device. Which is why everyone’s excited about this for Apple’s iSlate tablet PC, especially since The New York Times got an Apple engineer to explain.
Let’s get this right: There are indeed space-saving implications of the tech, but in terms of pure science we’re probably talking in the range of fractions of a millimeter thinner–nothing you’d ever really notice when holding the thing. But that thinner screen actually does have massive implications: It could result in significantly improved displays. This is something that the guys behind the Que e-reader, Plastic Logic, proudly mentioned during the product roll-out yesterday. Their plastic-based screen tech is cleverly thin so that there’s little in the way of transparent electronics between your eye and the e-ink screen, with the upshot of a brighter, more contrasty and crisper display. It’s particularly important when you’re talking about transreflective displays like e-ink, where light has to go through the layers twice, but a thinner less-layered solution would also benefit LCD and OLED screens too.