Touch screen

Touch screen technology had its first practical use in 1972 as an added feature on computer assisted learning system implemented by the University of Illinois. From then on, computers equipped with touch screen technology made its way into bank ATMs and on the consumer side, Personal Digital Assistant or PDAs. In the 1980’s the technology can only detect a single point at a time and sensitivity is a major issue. Exact point of contact cannot be accurately detected and its practical use was on hold until the emergence of newer systems. By the late 1990’s touch screen has regained popularity on highly capable PDAs and smart phones. Most touch screen systems are passive that requires physical contact of an external object to the resistive layers. The drivers used to compile input are identical to the system used on a mouse device.

On a resistive system, two electrically sensitive layers are used to detect the coordinates. The fields are sent to a driver that later compiles the information into the computer to detect the exact spot of contact. Another system used is capacitive sensing. Indium tin oxide on the device side serves as a conductor. Since the human body is already a conductor, a contact between the device and the human will result in a change of electrostatic field. The change is processed by a software that will ultimately determine the exact point relative to the display on the computer screen. Other touch screen systems include surface capacitance, projected capacitance, projected capacitance, optical imaging, and acoustic pulse recognition. The market demand for touch screen technology is fueled by advancements in smart phone and personal computer devices. It is projected that the technology would soon be an integral part in homes and businesses as automation is slowly gaining demand from both the consumer and the business side of the spectrum.


Touch screen players:
Tyco international.(NYSE : TYC)  US
Balda AG (XETRA: BAD)  Germany
Neonode Inc. (NASDAQ: NEON)   Sweden