Multi-touch technology makes it possible for a touchscreen or trackpad to sense input from two or more\xa0points of contact at the same time. This allows you to use multiple finger gestures to do things like pinch the screen or trackpad to zoom in, spread your fingers to zoom out, and rotate your fingers to rotate an image you are editing.
Apple\xa0introduced the concept of multi-touch on its iPhone smartphone in 2007 after buying Fingerworks, the company that developed the multi-touch technology. However, the technology isn’t proprietary. Many manufacturers use it in their products.
Popular applications of multi-touch technology are found in:
- Mobile smartphones and tablets
- Trackpads for use with laptop and desktop computers
- Touch tables, touch walls and whiteboards
How It Works
A multi-touch screen or trackpad has a layer of capacitors, each with coordinates that define its position. When you touch a capacitor with your finger, it sends a signal to the processor. Underneath the hood, the device determines the location, size and any pattern of touches on the screen. After that, a gesture recognition program uses the data to match the gesture with the desired result. If there is no match, nothing happens.
In some cases, users can program custom multi-touch gestures of their own for use on their devices.
Some Multi-Touch Gestures
Gestures vary among manufacturers. Here are a few multi-gestures you can use on a trackpad with a Mac:
- Tap with two fingers to right-click.
- Double-tap with two fingers to zoom in and back out of a PDF or web page.
- Scroll by sliding two fingers up or down.
- Swipe left or right with two fingers to show the previous or next page.
- Swipe from the right edge to show the Notifications Center.
- Tap with three fingers to look up a word or take an action with a date, address or phone number.
- Spread your thumb and three fingers apart to bring up the desktop (Mac only).
- Pinch your thumb and three fingers together to bring up the Launchpad (Mac only).
- Swipe left or right with four fingers to move between desktops or full-screen apps.
These same gestures and others\xa0work on Apple’s mobile iOS products such as iPhones and iPads.