A brief History of Capacitive Touchscreen Technology


Touch screen is a kind of HMI (Human Machine Interface). Before 2007, not many people paid attention to it. But after 2007, touch panels are used in all kinds of smart phones and tablets, it has become household name. Let’s talk a little bit about its recent story first.

It’s no secret that Steve Jobs had a huge impact on the world of technology, but perhaps his legacy will be felt most significantly in mobile. No matter the smartphone, it works the way it does now because back in 2007 Steve Jobs stood on a stage before a throng of reporters and said, “Who wants a stylus? … Yuck!”. Apple was not the first company to look at capacitive touch technology, but it was the first to make it really work on cellphones.

Indeed, Steve Jobs almost missed out capacitive touch technology on the iPhone and iPad altogether. That’s because he didn’t see “any value to the idea” of multi-touch: the breakthrough touchscreen technology which makes iOS regulars like “pinch-to-zoom” possible.

And it was left up to Ive and a few other core Apple employees to save it. Multi-touch at Apple began with a demo from Greg Christie and Bas Ording, who spent several months in 2004 creating a working prototype of an iPad-like screen, the size of a conference table. On it, a person could use two hands to move folders around, activate icons, shrink and enlarge documents, and “scroll” vertically and horizontally using swipes. They presented the tech to top Apple executives by projecting it onto a video screen.  Jobs had been excited about creating a tablet, but he was less than impressed by the demo.

After thinking about the idea for a few days, however, Jobs came around — and ran it past a number of Apple executives whose opinions he trusted. Jobs wasn’t immediately convinced he could make a go of a tablet as a mass-market product, but as a phone he could certainly see the application. He told Tony Fadell to “go figure out how to add this multi-touch interface to the screen of a phone. A really cool, really small, really thin phone.”

The rest, as they say, is history.

 

Who invented touch screen?

In 1965, E.A Johnson at Royal Radar Establishment in Malvern,  UK was considered as the first inventor for capacitive touch screen. He published his article about the touch screen technology in Ergonomics in 1967.

In 1971, Dr. Samuel Hurst (founder of Elographics) developed touch sensor which was patented by The University of Kentucky Research Foundation. But the touch sensor was not transparent.

In 1971, Plato IV terminal in University of Illinois was the first generalized computer with infrared touch systems.

In 1974, the first transparent touch screen with ITO (indium tin oxide) as conductor was developed by Sam Hurst and Elographics.

In 1977, Elographics developed the  resistive touchscreen (RTP) technology which is still used today. On February 24,1994, the company officially changed its name from Elographics to Elo Touch Systems.

In 1982, First multi-touchscreen device was developed at University of Toronto.

In 1983, Myron Krueger introduced Video Place, which can track hands, fingers and the people they belong to.

In 1983, HP (Hewlett Packard) introduced a HP-150 with touch screen technology. Infrared touch panel was used. 

In 1984, Bob Boie of Bell Labs developed the first multitouch screen overlay.

In 1993, Apple released the Newton PDA equipped with handwriting recognition; and IBM release the first smartphone called Simon with a touch screen that can be used to dial phone numbers.

In 1996, Palm introduced Pilot series PDA with advanced touch screen technology.

In 1999, Wayne Westerman and John Elias of FingerWorks introduced multi-gesture touchscreen devices.

In 2002, Microsoft introduced the Windows XP tablet with touch technology.

In 2007, Apply released iPhone and started the era of touch screen technology.

In 2011, Microsoft and Samsung partner up to introduce the SUR40 touch capable surface with PixelSense technology.

 

When did touchscreen computers come out?

Touchscreens began to become commercialized 1983 when HP (then known as Hewlett-Packard) created the HP-150. This computer featured a 9” CRT display, with infrared (IR) detectors around the edge that could detect when a user’s finger interacted with the screen.

 

Do capacitive touch screens wear out?

We have to classify the “wear” physically or electrically.  Physically, it is difficult to wear out your touch screen unless you use keys or diamond to scratch the touchscreen. The surface hardness of different touchscreens are different. Some low end touch can be as “soft” as 2H, but iPhone surface can be as hard as 9H made by chemically tempered glass panel.

 

What triggers capacitive touch screen?

Capacitive touchscreens , or capacitive touch panels (CTP) are made from multiple layers of glass or insulator. The inner layer conductive material conducts electricity and so does the outer layer to be a capacitor. When your finger close or touch the screen, your body/finger changes the electrical field by a certain amount that varies. The touch sensing circuitry will sense the capacitance changes and trigger the touch.

 

Evolution of capacitive touch screen

Surprisingly, the first touchscreen device was capacitive rather than the resistive technology in 1960s. At that time, the touchscreen was bulky, slow, imprecise and very expensive.  The technology was mono- touch or single touch and simple. The capacitive touchscreen technologies didn’t have much progress because of the huge success of the resistive touch panel. But people tend to search for novel input ways. The change came in 2007 with the introduction of the iPhone , the iPhone introduced an accurate, inexpensive, multi-touch technology.

 

Capacitive touchscreen present and future

Now, it’s almost unthinkable if we don’t have capacitive touch display. It has become part of our daily life, tap, drag, flick, zoom in/out, swipe etc.  The touchscreen technology not only used in tablet or smartphone. Touchscreens really are everywhere. Homes, cars, restaurants, stores, planes, bank in ATMs, point-of-sales, kiosks,  air traffic control etc., wherever—they fill our lives in spaces public and private. The touchscreen changed from mono-touch to multi-touch with as many as 16 touch points,  to 3D touch (force touch by press down), to hover touch (without actual touch), to haptic touch (sense the vibration after effective touch), to glove touch materials ( from latex to nylon to wool with different thickness), to wet touch (with water or salt water), with different touch materials ( from finger, pencil, stylus etc.), to different kind surface materials (glass, plastic, sapphire crystal), to different shape (flat, curved, sphere),  to different thickness ( thick, thin, no actual sensor glass (on-cell), no actual touch panel (in-cell))… The capacitive touchscreen technology can be old but we can see it is also young. As the main HMI (human machine interface input/output device), there are still a lot to come.