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.
Not all touchscreen devices support multi-touch. While it’s become a common feature in many smartphones and tablets, there are still some touchscreen devices that require single-touch commands. Fortunately, multi-touch is supported by most self-capacitive touchscreens. Self-capacitive touchscreens are able to desensitize other areas to allow for accurate and responsive multi-touch commands.