'TOUCHSCREEN'



"TOUCHSCREEN"
        A ninput device that allows user to interact with computer by touching the displayscreen. Often this uses beams & interact light that are projected accross screen surface. Interrupting the beams generates an electronic signal identifying the location of the screen. Software interprets the signal & performs the required operation. 


FOUR TYPES OF TOUCHSCREEN TECHNOLOGIES:
     1.) INFRA RED- It works by sending infra red beams across the screen 
              in a green pattern. As you touch the screen you interrupt the 
              grid & your interruption becomes your touchpoint.
    2.) RESISTIVE MEMBRANE- Relies on a pressure that is applied by 
              pushing on a plastic membrane that lays over the screen. This 
              technology is preferred where users must wear gloves.
    3.) SURFACE ACOUSTIC WAV(SAW)- Sends an acoustic wav across the 
              top surface of the screen.
    4.) CAPACITIVE- Most advanced technology that offers the