Touch screens ?

Touch screens ?

1. invented 1965

   • used for airplanes, stores, banks, schools, hospitals

2. Resistive

   • 1 layer - conductive polyester 2 - conductive glass separated by insulating membrane
     • when layer is pressed, a circuit is completed because of the electric current between the layers.
       • the position is calculated by a microprossesor
         • atms and cashiers
           • durable but hard to read

3. Capacitive

   • glass layers
     • Indium Tin oxide coated
       • forming grid
   • when touched it changes electric field at that position, calculated by microprossesor
   • phones
   • projective or surface type

4. infra red

   • grid pattern of LED and photocells (light sensors)
     • LED shine infra red
       • disrupted when touched screen
         • lazers example

5. Surface acoustic waves

   • ultrasonic sound waves
     • recieving and transmitting tranducer are used to generate waves
       • wave reduced when touched

6. AMOLED

   • remarkable colours, deap black, eye searing contrast ratios, energy efficient, flexible
   • LCD subduded colors