Unit 1

Information Technology
Touch screens aren´t relatively new maters as it can seem to us. They did take off at some markets such as point-of-sale-equipment because they were hard-wearing, weatherproof and simple to use.
But breaking into the consumer market was a different matter entirely. Some personal digital assistants, or PDAs, such as the Palm Pilot, had touch screens, but they had been overshadowed by the rise of advanced mobile phones that offer similar functions, combined with communications and also were more elegant that PDA.
But then Apple invited their iPod – mobile phone with touch screen where on-screen objects behave in physically realistic ways. People started to demand the same quality of design: they didn´t just want functions. This is a reason why Apple did an outstanding job with the iPhone in every aspect.
Until recently, the public might not have been ready for such interfaces as using touch screens at their desktop computers, but right now the public is ready. It´s true that there are some factors that held back touch screens such as lack of support for the technology in operating systems, but Apple and Microsoft have added multi-touch support to OS X (the operating system that powers Macs and iPhones) and Windows..
The first type of these computers were Microsoft's Surface - a computer built into a tabletop with multi-touch input – which were deployed in hotels, restaurants and casinos.
Surface uses under-the-table projection to produce the tabletop image. The screen is also illuminated from below with infra-red light, which reflects off objects in contact with the screen. These reflections are detected by cameras, also mounted beneath the table.
There are also perceptive Pixel's huge touch screens which also use cameras to detect touch inputs, but in a different way. When someone presses the sheet with a finger some of the light leaks out of the sheet at the point of contact. This light is picked up as a bright spot by an infra-red camera behind the screen. Touching the screen in many places at once results in several spots.