Capacitive Touchscreen

Capacitive Touchscreen There are lots of touchscreens which differ in design as well as in operating principle. These devices use various technologies, such as resistive, capacitive, matrix, inductive, acoustic and infrared ones. Let us study the operation of a capacitive touchscreen in particular. The operation of the capacitive touchscreen is based on the fact that a high-capacity object conducts electric current. In this case the position of a contact point can be defined due to the features of human body structure, namely the capability to conduct current and presence of capacity. Before touching the screen bears some electric charge. When the screen is touched the point with the potential lower than the potential of the electrodes appears in the conductive layer. The electrodes located in all four corners follow the charge current in the screen and define the position of the contact point in that way. The accuracy of capacitive screens is comparable to one of resistive screens. The capacitive screens feature higher reliability due to absence of the flexible membrane and fewer layers make them more transparent. Such screens allow up to one hundred presses in one point. But actually the capacitive screens have their minuses as well. You have to touch the screen only with a conductive object (finger or stylus). These screens do not allow simultaneous touching of two in two points. Principle of capacitance is sometimes used in "standard" keyboards. These keyboards feature higher reliability and dust and moisture immunity if compared to mechanical and membrane keyboards.

Category:

Science & Technology

Tags:

• capacity
• current
• display
• touch screen