Touch-Screen Samsung UMPC Thumb Keypad

By Cho Jin-seo
Staff Reporter

Don't push. Just touch.

From car navigators to rice cookers and from ATMs to iPhone, buttons and dials on electronics appliances are being replaced by touch-sensitive screens.

Touch-screens are the displays that can read the touch of fingers or other sharp objects on them with built-in overlay sensors. Invented in the early 1970s, these types of screens have been most widely used in public spaces such as bank teller machines, automatic ticket machines and museum displays, because they allow a more intuitive interaction between users and the screen without using additional devices such as a keyboard or a mouse.

But now the touch-screen technology is entering a new stage. Thanks to the rapid development of mobile electronics gadgets, it is adopted to PDAs (personal digital assistants), car navigators, high-end mobile phones and MP3 players.

The successful debut of the iPhone in the United States this summer signaled the beginning of the touch-screen frenzy. And all the hype around such devices won't fade away soon, industry watchers say.

``It is clear that the capacitive touch-screen is not a fad,'' said Yvonne Jang, Korean manager of Synaptics. Symaptics is a firm famous for making the Touchpad that is used in most laptops. Since 2005, the firm started producing capacitive (electrically sensitive) touch-screen panels for mobile devices.

``We have seen rapid adoption of capacitive technology for mobile and other handheld devices. Capacitive is the intuitive choice for OEMs. Devices are becoming thinner, smarter, with more advanced applications and richer media,'' she said.

According to research firm DisplayBank, the worldwide touch-screen panels market is expected to grow 46 percent this year to a total of 290 million units. It is palm-sized mobile gadgets such as phones, car navigation systems and portable game consoles that contribute to most of the growth, the report says.

Korean firms are not behind this trend. Actually, they are leading it. The three major phone makers _ Samsung Electronics, LG Electronics and Pantech ― have used capacitive panels provided by Synaptics to make innovative products.

Actually, it was LG Electronics that pioneered the full-size touch-screen phone field with the launching of Prada Phone earlier this year, several months earlier than the release of Apple's iPhone.

Pantech is selling a ``Magic Keypad'' phone. The handset's each numeric keypad is a separate touch-screen, which can change fonts, shape and colors.

As it is always obsessed with new technologies, Samsung also has made significant efforts in adopting the touch-screen technology in various gadgets ― phones, MP3 players and Ultra Mini-PCs. Early last year, the firm showed a unique touch-screen keypad system for its UMPC Q1, which is designed to be typed with two thumbs while holding the body of the mini PC with both palms. Though the UMPC didn't sell very much, the ingenious design of the thumb-keypad received a lot of attention.



Slowly but clearly, the Korean firms are seeing successes coming from their touch-screen products. Samsung said that its P2 ``Palm Theater'' music player is selling more than 30,000 units per month in South Korea only, which is impressive considering it is a high-end product and the market is almost saturated. Encouraged by the sales figure, the company launched the same product in the United States this month with an extravagant ceremony at New York's Time Warner Center.

``The foremost innovations and electronics emerge from this region,'' Jang said about the Korean firms. ``It is no surprise that Korea was the first to implement capacitive technology in their mobile devices.''

How to Sense Human Touch

There are a number of methods of how to capture the touch of human fingers, or other objects such as a stylus pen, on an LCD screen. The two most widely used touch-sensitive screens are the resistive (pressure-sensitive) type and the capacitive (electric capacity-sensitive) type.

The resistive type is more traditional, simple, and cheaper to produce. This type of panel has two thin metallic layers inside, which are separated by a narrow space. When some object touches the panel, the layers connect at the point of the pressure, producing an electrical signal.

Capacitive type is a bit more complex and therefore more costly to produce. It is coated with a certain material where a continuous electrical current runs across it all the time. When a finger touches it, the strength and direction of the electric current is affected because the human body itself is a conductor of electricity, though most of us are not aware of this.

As this type of sensor does not need much pressure, the capacitive type is usually considered more accurate in reading the human touch. But at the same time, the capacitive panel cannot recognize the contact of nonconductors of electricity, such as plastics, wood and gloved fingers. As the iPhone uses this type of panel, there have been reports that people with long nails have problems controlling it.

The growing popularity of touch-screens is related to the development of the mobile Internet environment. As more phones now support wireless Internet browsing, manufacturers want bigger screens. Touch-screen displays are a natural choice because they eliminate the needs for a keypad. Apple was the first to implement the full-browsing Internet function into its iPhone.

Touch-screens also provide simpler and more stylish designs, so it is now being introduced in many unlikely places. For an example, mid-sized kitchen appliance maker Bubang is selling a rice cooker in Korea that has a touch-screen control on the front.

Ergonomics Issues

The iPhone is being lauded for opening the new horizon of multi-touch capability. While most touch-screens can detect one input (touch of finger) at a time, the iPhone can detect multiple touches simultaneously. So the so-called multi-touch function allows users to zoom in and out of web pages and photos by placing two fingers on the screen and spreading them farther apart or closer together, as if stretching or pinching the image.

But the touch-screen technology has clear downsides as well. Its lack of physical sensations such as the feeling of pushing a button or rotating a dial, users aren't sure if the machine properly receives their touches.

Engineers have been trying to solve the problem by giving various kinds of feedback. ``Our customers have used a combination of tactile, visual, and audio feedback to simulate the feeling of a button press or scrolling interface,'' Jang of Synaptics said. ``Some of these solutions include LED animation, ridged surfaces, vibrations, as well as audible tones or clicking noises.'' Both LG and Samsung Electronics introduced vibrating touch-screen phones.

indizio@koreatimes.co.kr