Design Articles

The Evolution of Touchscreens in Portable Consumer Electronics

Touchscreen technology has come a long way from the original PalmPilot to today’s 3G iPhone.

By Darrin Vallis, Director, Touchscreen Solutions, Cypress Semiconductor

In 1997, the Motorola Startac and Palm Pilot (Figure 1) were state of the art consumer electronics for the mobile professional. They were superb tools for staying in touch with customers, managing your calendar and organizing contacts.

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Figure 1: Motorola Startac and PalmPilot

Many Portable Information Managers or Electronic Organizers were developed in the 1980s, but did not achieve mass market acceptance. Problematic user interfaces were the main issue. Apple CEO John Sculley introduced the Newton “Personal Digital Assistant” at CES in 1992, but its high price, somewhat large size and troublesome handwriting recognition limited sales. Finally, in 1996 US Robotics released the first PalmPilot PDA. It combined a touchscreen, handwriting recognition and intuitive user interface in a small form factor with excellent battery life. This first successful implementation of a PDA demonstrated the true utility of touchscreens in portable consumer electronics.

Resistive touchscreens used on the PalmPilot still had their issues. The screen would sometimes lose alignment and not recognize touch positions correctly, requiring a recalibration. Display brightness was somewhat dimmed by the touchscreen transparency. Also, the screen could suffer failures over time due to mechanical flexing of the top layer.

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Figure 2: Research In Motion
BlackBerry 850

Some companies approached the user interface problem from other angles, and succeeded. Research In Motion released their BlackBerry 850 in 1998 (Figure 2). It was a unique combination of wireless connected email with built-in PDA functionality.

The keyboard was small, but very ergonomic, and turned out to be ideal for quickly typing email. As well, the operating system and applications well designed, with excellent integration and usability. In fact, RIMs email application was licensed for by Nokia, Motorola, Samsung, Sony Ericsson, Siemens, HTC and QTeck for their own cell phone designs. RIM went on to enter the handset market with a portfolio of increasingly sophisticated smart phones, and eventually claim the #1 market share.

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Figure 3: Motorola Razr V3

Further evolution in semiconductors, LCDs, batteries and material technology brought remarkable products to market. Motorola’s 2004 Razr is a prime example (Figure 3). The impossibly slim, stylish design was an instant success, selling over 50 million units in just two years, and is still popular today.

Still, the Razr was a poor substitute for calendar or address book applications. Anyone trying to type a significant amount of text with a phone keypad has experienced this issue. Once again, user interface was the limiting factor for portable device functionality.

Meanwhile, cell phone manufacturers were still testing the market with various user interfaces. Palm continued to incorporate resistive touchscreens with their Tungsten, Zire and Treo models. The Sony Ericsson P800 (2002), Motorola A780 (2003), BENQ P30 (2004) and AT&T 8525 (2006) also tried resistive touchscreens. Swedish manufacturer Neonode launched the N1 phone in 2004 with an IR optical touchscreen. Each phone had its high points, but neither significantly changed the industry.

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Figure 4: LG KE850 Prada Phone

In late 2006, LG released their first touchscreen phone, the Prada (Figure 4). Originally available in tri-band GSM for the European market, the Prada had a unique industrial design enabled by capacitive touchscreen technology.

Known as “Projected Capacitive”, this type of touchscreen uses indium-tin-oxide (ITO) transparent metallic sensing elements deposited on a glass or film substrate. The result is a very rigid, scratch resistant, highly transparent touchscreen with excellent accuracy and no need for calibration. In addition, projected capacitive technology also enables multi-touch, an important feature for portable electronics user interfaces. Consumer demand for this new “look and feel” was clear, with LG selling over 800,000 Prada phones in 2007.

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Figure 5: Apple iPhone

In June 2007, Apple entered the smart phone market with their much anticipated iPhone (Figure 5). The instantly recognizable sleek and minimalist industrial design was realized with capacitive touchscreen technology. Apple showcased the true possibilities for touchscreen-enabled consumer electronics with their highly integrated suite of applications. The entire front surface of the device became a reconfigurable, context sensitive, multi-touch user interface.

Driven by Apples’ formidable marketing machine, iPhone became an overnight phenomenon, with people lining up for hours or even days to purchase the device. iPhone coverage was in magazines, newspaper, blogs, TV and innumerable web articles. By May of 2008, sales reached more than 5 million units. Capacitive touchscreen technology was now the de-facto gold standard for portable consumer electronics.

Bases on the success of LG and Apple, we can expect to see many more capacitive touchscreen designs from major manufacturers of cell phones, GPS and MP3 players. iSupply predicts the market for these portable touchscreen enabled devices will grow from 330 million units in 2008 to 800 million units in 2013. Projected capacitive market share is expected to grow from 10% to 16% of over the same period, with the remainder being resistive touchscreens. These numbers may still be conservative. Forecasts for the growth of projected capacitive touchscreens have been higher each year since 2006, supported by the market success of devices using this technology.

Projected capacitive touchscreens are here to stay for portable consumer electronics.

Cypress Semiconductor
San Jose, CA
(408) 943-2600

This article first appeared in the August, 2008 issue of Portable Design. Reprinted with permission.

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