Resistive touchscreen

In electrical engineering, resistive touchscreens are touch-sensitive computer displays composed of two flexible sheets coated with a resistive material and separated by an air gap or microdots. There are two different types of metallic layers. The first type is called Matrix, in which striped electrodes on substrates such as glass or plastic face each other. The second type is called Analogue which consists of transparent electrodes without any patterning facing each other. Analogue also offers lowered production costs.. When contact is made to the surface of the touchscreen, the two sheets are pressed together. On these two sheets there are horizontal and vertical lines that, when pushed together, register the precise location of the touch. Because the touchscreen senses input from contact with nearly any object (finger, stylus/pen, palm) resistive touchscreens are a type of "passive" technology.

For example, during operation of a four-wire touchscreen, a uniform, unidirectional voltage gradient is applied to the first sheet. When the two sheets are pressed together, the second sheet measures the voltage as distance along the first sheet, providing the X coordinate. When this contact coordinate has been acquired, the uniform voltage gradient is applied to the second sheet to ascertain the Y coordinate. These operations occur within a few milliseconds, registering the exact touch location as contact is made.

Resistive touchscreens typically have high resolution (4096 x 4096 DPI or higher ), providing accurate touch control. Because the touchscreen responds to pressure on its surface, contact can be made with a finger or any other pointing device.

Comparison with other touchscreen technology

Resistive touchscreen technology works well with almost any stylus-like object, and can also be operated with gloved fingers and bare fingers alike. In some circumstances, this is more desirable than a capacitive touchscreen, which has to be operated with a capacitive pointer, such as a bare finger (gloves will not work on capacitive touchscreens). The costs are relatively low when compared with active touchscreen technologies.^{[citation needed]} Resistive touchscreen technology can be made to support multi-touch input.

For people who must grip the active portion of the screen or must set their entire hand down on the screen, alternative touchscreen technologies are available, such as active touchscreen in which only the stylus creates input and touches from the hand are rejected. However, there are now newer touchscreen technologies which allow the use of multi-touch without the aforementioned vectoring issues.

See also

• Capacitive sensing
• Graphics tablet
• Pen computing