Touch switch technology was originally designed for use in industrial applications; today touch switches are incorporated into panels and window areas.
Capacitive Touch Keypads
Capacitive touch panel technology is a unique and reliable new way to provide capacitance touch interfaces with no moving parts. It’s a robust technology ideal for resistance to harsh chemicals and extreme environments.
A capacitive switch uses an electrical field to detect the presence of your finger or any conducting object, recognizing a change in capacitance which indicates a touch switch actuation. Capacitive designs may incorporate several touch switch formats and layouts, including slide switches, rotary wheels, discrete wire and both tactile and non-tactile options
Capacitive touch interfaces are built on polyester circuits, printed circuit boards or polyimide flex circuits. The overlay graphics on top of a capacitive switch are available in a wide selection that include glass, polycarbonate, polyester, or acrylic…Backlighting is available as an option.
Resistive Touch Screens
Resistive touch screens are the most popular touch screens as they are the least expensive of all touch screens. Sigma 6 Electronics, Inc. manufactures standard and custom resistive touch screens available as both digital touch screens and analog touch screens (4, 5, and 8 wire).
Digital Touch Screens
The digital touch screen, also referred as X-Y Matrix touch, ITO coating is etched to form a series of multiple rows and columns, assembled to make a matrix of discrete switches. The resolution is dependent on the number of rows and columns and each switch is a permanent discrete location and the size cannot change.
Digital touch screens are easy to integrate with membrane switches and are popular when finger size touch areas are required.
Analog Touch Screens
The analog touch screen has the highest resolution, limited only by the LCD, its construction is often used when a much higher resolution of switches is required than is possible with the digital touch screen. This touch screen only needs a 4 or 5 pin connector compared to the digital touch screen needing one pin for each row and each column. Each layer carries an X or Y axis, when the two layers are placed on top of each other a single switch is created. Wherever the analog touch screen is touched a voltage drop is sensed by the CPU and locates the users touch.
