TOUCH SCREEN TECHNOLOGY

Touch Screen Technology

Touch Screen Technology

By far the most popular input device used today for interactive processing and for online entry of data for batch processing is the visual display terminal (VDT). A keyboard is used to enter data in to a processor, and a video display unit called a monitor is used to display the keyed data and to receive messages and processed information from the computer. Most of the VDT monitors are cathode ray tubes that look like a television picture tube; however, there are other display technologies that are available. One such category is the user-friendly hardware interfaces. An interface is a shared boundary between people and machines. This boundary includes both software and hardware. The software developers create programs with a user-friendly interface that use menus and graphic features, and are thus easier for the people to learn and apply. Some of the VDTs and computer systems allow users to enter limited amounts of data simply by touching sensitive areas of the screen.

For instance, small boxes displayed on touch screen may perform like special function keys. Touching one of these boxes may cause the system to store a document, center a line, or carry out some other preprogrammed task. Touch screens are also used for menue-driven applications where the operator can simply point to a menu choice and receive a response from the system. Although user friendly, touch screens cannot be used to enter large amounts of data. Thus, defining precisely touch screen: “The Touch Screen is a compact and versatile operator interface or control panel. With a touch on the screen the operator can start, stop, change speeds, change limits, and monitor the status of the machine and transfer the machine status and product data to a central factory network. All the tasks mentioned could be performed by the operator while the packaging machine is running. The Touch Screen is attached to the frame by a heavy-duty swing arm that permits movement of the interface to a convenient position Baldor has added two advanced touch-screen operator interface panels to its range of motion control system building accessories. The panels provide rugged display facilities for industrial machinery, capable of displaying sophisticated quarter VGA size graphical man-machine interfaces, or up to 16 lines x 40 characters of text” (http://www.blair-fuehrer.com/work/userpanel.htm).

The intelligent terminal combines the VDT hardware with built-in micro processor that are user programmable. They can process small jobs without the need to interact with the larger computer. Programmed checks can test the validity of input data being entered at the intelligent terminal or at dumb terminals linked to the intelligent station. After data have been collected and edited, they can be stored for later transmission to a larger computer. The cost of adding microcomputer components to a dumb terminal has now dropped so low that almost all new VDT's have smart or intelligent features to help make data entry and retrieval easier for people. There is very little difference between the intelligent terminal and a ...