Multi-Touch for Self-Capacitive Touchscreens
Multi-touch is a common feature in many touchscreens devices. Whether you're using a smartphone, a tablet or any other touchscreen device, it may support touch commands involving two or more simultaneous points of contact. Known as multi-touch, it's available in self-capacitive touchscreens. Self-capacitive touchscreens still support single-touch commands, but you can usually control them with multi-touch commands as well.
What Is a Self-Capacitive Touchscreen?
A self-capacitive touchscreen is a type of touchscreen device that uses a grid of sensors to detect changes in a uniform electrostatic field. It's essentially a variant of capacitive touchscreen technology. All capacitive touchscreens detect touch commands by measuring a uniform electrostatic field. When performing a touch command with a conductive object, such as a bare finger, the electrostatic field will change. Capacitive touchscreens will then register this change in capacitance as a touch command.
What makes a self-capacitive touchscreen different from other capacitive touchscreens exactly? The main difference is that they feature independently operated rows and columns of sensors. The sensors are still arranged in a grid. The rows and columns, however, can operate independently of each other.
Self-capacitive touchscreens are similar to mutual capacitive touchscreens. The main difference, though, is that self-capcitive touchscreens have independently operated rows and columns of sensors, whereas mutual capacitive touchscreens do not. With their independently operated rows and columns of sensors, self-capacitive touchscreens are more accurate, they also support multi-touch commands.
How Multi-Touch Works in Self-Capacitive Touchscreens
Multi-touch, of course, refers to the use of a two or more points of simultaneous contact. In other words, you perform different commands using multi-touch by placing two or more fingers - or styluses - against the display interface. In self-capacitive touchscreens, desensitizing is used to support multi-touch.
All self-capacitive touchscreens have rows and columns of sensors that operate independently of each other. With their independent operation, they can be desensitized. Self-capacitive touchscreens will typically only register a maximum number of contact points at any given time, such as two. After registering these contact points, the other areas of the display interface will be desensitized.
