An iPad's touchscreen functionality relies on a technology called a
capacitive touchscreen . Så här fungerar det:
1. Capacitive Layer: The outermost layer of the iPad's display is a thin layer of electrically conductive material, typically indium tin oxide (ITO). This layer is a capacitor.
2. Electric Field: This conductive layer is charged with a small electrical current.
3. Touch Detection: When a finger (or a capacitive stylus) touches the screen, the finger's capacitance (its ability to store electrical energy) disrupts the electric field in that specific area. The change in the electric field is detected by a controller.
4. Location Identification: The controller precisely measures the change in capacitance and its location on the screen. This information is then used to determine exactly where the touch occurred.
5. Signal Processing: The controller sends this location data to the iPad's processor, which interprets the touch as an input and performs the corresponding action (e.g., opening an app, typing a letter).
In essence, your finger acts as a conductor, completing a circuit and altering the electric field of the capacitive layer. The iPad's sophisticated electronics detect this change and translate it into a usable input.
Unlike resistive touchscreens (older technology), capacitive touchscreens are more sensitive, durable, and provide a more accurate response to touch. They also don't require the direct pressure needed for resistive screens.
