# How Multi-Touch Screens Track Multiple Fingers at Once > Apple's 2010 patent describes a touch screen that uses two layers of transparent conductive lines to detect several fingers touching the screen simultaneously. - **Patent:** US 7663607 - **Original title:** Multipoint touchscreen - **Owner:** Apple Inc - **Granted:** 2010 - **Status:** Public domain (expired) - **Times cited:** 1,995 - **Field:** consumer_electronics, semiconductors ## What it does The patent describes a system using a grid of transparent conductive lines, typically made of Indium Tin Oxide (ITO), arranged in two separate layers. These layers are stacked so the lines in the top layer run perpendicular to the lines in the bottom layer. By monitoring the charge coupling at the intersection points of these lines, the system can pinpoint exactly where multiple fingers touch the screen at the same time. This allows a device to distinguish between a single tap and complex gestures like pinching or zooming. ## What it does NOT cover - Does not cover single-touch screens that only detect one point of contact at a time. - Does not cover resistive touch screens that rely on physical pressure to connect two flexible layers. - Does not cover non-transparent touch sensors used in trackpads or other non-display surfaces. - Does not cover the software algorithms used to interpret the touch data into specific gestures like pinch-to-zoom. ## The clever bit The innovation lies in using a cross-grid of transparent conductive lines to create a coordinate system that can report multiple distinct touch events simultaneously, rather than just the average location of multiple touches. ## Real-world examples 1. Original iPhone and subsequent iPhone models 2. iPad touch displays 3. Modern capacitive smartphone screens 4. Multi-touch tablet interfaces ## Why it matters This patent was a cornerstone of the modern smartphone era, enabling the intuitive multi-touch interface introduced by the iPhone. It provided the hardware foundation for replacing physical keyboards with dynamic, gesture-based touch displays. It has been a central piece of intellectual property in numerous high-stakes patent battles within the consumer electronics industry. ## Frequently asked questions ### What does How Multi-Touch Screens Track Multiple Fingers at Once cover? Apple's 2010 patent describes a touch screen that uses two layers of transparent conductive lines to detect several fingers touching the screen simultaneously. ### Who owns patent US 7663607? Apple Inc owns this patent, granted in 2010. ### When does this patent expire? This patent has expired and is now in the public domain — anyone can use the invention freely. ### What is patent US 7663607 cited by? This patent has been cited by 1995 later patents that build on its ideas. ### What problem does this patent solve? This patent was a cornerstone of the modern smartphone era, enabling the intuitive multi-touch interface introduced by the iPhone. It provided the hardware foundation for replacing physical keyboards with dynamic, gesture-based touch displays. It has been a central piece of intellectual property in numerous high-stakes patent battles within the consumer electronics industry. ### What does this patent NOT cover? Does not cover single-touch screens that only detect one point of contact at a time. **Full plain-English explainer:** https://patentbrief.org/patent/us/7663607/multipoint-touchscreen **Original patent:** https://patents.google.com/patent/US7663607 --- _Source: PatentBrief — https://patentbrief.org. Patent facts are from public records; the plain-English explanation is PatentBrief's._ ## Related patents Semantically similar inventions in the PatentBrief corpus: - [How Touchscreens Tell Real Touches From False Ghost Touches](https://patentbrief.org/patent/us/8619056/ghost-resolution-for-a-capacitive-touch-panel) — A method for capacitive touchscreens to distinguish between actual finger presses and false ghost signals that occur when multiple points are touched simultaneously. - [How Multi-Touch Gestures Like Pinch-to-Zoom Work on Smartphones](https://patentbrief.org/patent/us/7812826/iphone-software-keyboard) — Apple's patent on using two-finger gestures to manipulate images and objects on a touchscreen, allowing for smooth zooming and rotation even if you lift your fingers briefly. - [How a Multi-Touch Screen Detects Multiple Fingers and Palms](https://patentbrief.org/patent/us/6323846/aqua-user-interface) — This patent describes the underlying electronic circuits and methods for a multi-touch surface that can track multiple fingers and palms simultaneously, even before they fully touch the screen. - [How Touchscreens Precisely Align Signals to Detect Your Touch](https://patentbrief.org/patent/us/8493330/individual-channel-phase-delay-scheme) — Apple's patent describes a way for touchscreens to adjust the timing of internal electrical signals so they perfectly match the signals coming from your finger, making touch detection more accurate. - [How Touchscreens Use Math to Recognize Your Fingers](https://patentbrief.org/patent/us/7812828/ellipse-fitting-for-multi-touch-surfaces) — Apple's patent on using mathematical ellipses to track and identify individual fingers and palms on a touch-sensitive surface.