Brainstorm: Optoelectronics

 What will be the next big advance in touchscreen technology?

Binay Bajaj, Atmel,

The existing touchscreen technology available for large screens has been limited in capability and function. The next big advance in touchscreen technology enables truly unlimited capacitive touch functionality for large format touchscreens. These technology solutions will support large touchscreens, including those above 15 inches, for emerging products, including touch-enabled tablets, smartbooks, mobile Internet devices (MIDs), Netbooks, PC notebooks, and a range of industrial applications. As the basis for these applications, the technology will enable high-resolution screens, faster response, stylus support, unlimited touch, and more accuracy for enhanced consumer experience, basically bringing all the functionality consumers are used to in the small formats to the large screen.

With true unlimited touch functionality and stylus support, the new chip technology will enable exciting new software applications and user interactions on one screen. Devices with this technology will offer higher performance, faster response time and reject all unintended finger and face touches to provide a better user experience. The larger screen technology will provide optimized and enhanced unlimited touch sensing with the fastest touch response time, lowest power and extremely high-touch accuracy and linearity for finger touches and stylus support.

Today’s user interface requirements for advanced touchscreen functionality include rejection of unintended touches, stretch/pinch and rotate gestures, handwriting and shape recognition, including face detection on mobile phones, and grip suppression and palm rejection on mobile Internet devices (MID) and Netbook screens.

Sherif HannaSherif Hanna, Cypress Semiconductor,

There are two areas that present the potential for advancement immediately.
First up is the integration of sensing elements into display panels. Currently, most touchscreens are made of one or two additional layers of film or glass that sit on top of a display panel such as an LCD. Though this model works presently as developers race to add touch interfaces to their products, it is not viable in the long term because of cost. Instead, the existing protective layer which already covers most display panels will in the future be used for touch sensing as well. This would reduce the overall cost of end products.

Next, touchscreens will become better at understanding the user’s intentions. Currently, all touchscreens can register touches in a “digital” on-off sense. Though this is sufficient for tapping and scrolling, it is problematic for more complex interactions, such as text entry. Users are accustomed to resting their fingers on their physical keyboards before proceeding to type. But with current touchscreens, resting one’s fingers on an on-screen keyboard leads to unintentional key presses. Future touchscreens will be able to interpret, among other things, the pressure applied by the user as a measure of their intention. User interface designers can then utilize this information to eliminate user frustration and streamline their touch experience.

Walter Lau, Avago Technologies, 

We are seeing touchscreens proliferate into everyday consumer devices such as smartphones, GPS personal navigation devices, portable media players, digital cameras, and most recently the hot new tablet device category ignited by the Apple iPad.  Looking into the future, literally any device with an electronic display is fair game for touchscreen adoption.

The smartphone category, being the largest segment of the touchscreen market, is driving advances in touchscreens.  First, there is a dramatic shift from resistive to projected capacitive technology which provides a more sensitive and responsive touch user experience, initially popularized by the Apple iPhone.  According to Display Search, projected capacitive will surpass resistive as the leading touch technology in 2010 and nearly all new touchscreen smartphone releases in the US will feature capacitive technology.

Second, future touchscreens are able to track higher number of touch inputs.  Most of the new smartphone models support two-finger multi-touch, such as the pinch zoom in/out feature.  Going forward, smartphones will be able to track up to 10 touchpoints, allowing the device to track more fingers for certain apps and games, in addition to tracking unwanted inputs such as the unintended touches when the fingers wrap around the phone when holding it in your hand.

Third, the popularity of the touch interface in smartphones has spread to other larger consumer display devices, such as tablets, e-books, electronic picture frames, notebooks, and All-In-One desktop PCs.   The size of touchscreens has grown from 3.3 diagonal inches in smartphones, to 10 inches in tablets, onwards up to 24 inches in All-in-One (AIO) PCs.  Capacitive technology will remain the dominant technology for screen sizes up to 18 inches in the notebook category.  Due to high capacitive touch panel cost, optical sensing technology is most commonly used for touch displays larger than 20 inches.

Jeff BlakeJeff Blake, Dontech, 

Touch screens have become a widely adopted user interface because they provide a rapid and intuitive means of operating electronic display devices.  The >30% annual growth forecasted for the touch screen market includes resistive touch screens which represent approximately 50% of the market, as well as “multi-touch” technology, which has attracted a great deal of interest.  Projective capacitive touch screens are growing at the fastest pace in the mobile phone market (e.g. Apple’s iPhone).  Market growth is expected in multi-touch and resistive touch screens, as well as in the consumer computer monitor and laptop markets due to the introduction of Windows 7 software which enables “all-in-one” monitors.

Traditionally, touch screens needed physical contact, or in the case of IR or NFI touch screens, proximate contact to operate.  New touch screen technologies, include a “hover” interface, where the input device will open applications (similar to a drop down menu) without touching the screen.  This type of technology provides more precision in operating a touch screen and could replace the functions of a mouse.  Even more advanced is “gesture technology” which uses hand gestures to activate the touch screen.  This technology requires advanced sensing such as camera-based touch screens to detect remote or complex hand movements.  Standardization still needs to be developed with this technology in order to increase its applicability.

Because more touch screens are being used in demanding environments, further modifications such as optical enhancements, impact resistance and EMI/RFI shielding properties are being incorporated to expand their functionality.  Through these enhancements, previous touch screen limitations have been removed for mobile, outdoor and avionic applications, enabling continued expansion in these areas.

Larry MozdzynLarry Mozdzyn, Ocular, 

Increases in available projected capacitive touch panel sizes are the next big advance in touch screen technology and will shape the future of how we interact with our devices and thus each other. From 15” to eventually 52” sizes, companies will find ways to incorporate

large scale panels with displays in a significant portion of their product portfolios. Large size multi-touch panels will enable the practical adoption of true multi-touch collaboration between individuals, changing the way that people communicate, interact and collaborate in the workplace, at school and in their daily lives.

It will be a gradual process, as in most technology advances, it won’t jump from a [currently available] 10.1” to a 52” overnight.  Finding a cost effective way to produce such an advanced technology will be a challenge to some, but those who can identify the process will be successful.

Touch panels are changing the way consumers interact with their devices and also their expectations: they always want the next “big thing.” This holds true in relation to highly sought after touch interaction, a bigger touch panel will meet their demands.