How Touchscreens Save Battery by Sleeping Between Touches
A power-saving method for touchscreens that puts the main processor to sleep when not in use and wakes it up only when a touch is detected.
Original patent title: “Multi-touch auto scanning”
A power-saving method for touchscreens that puts the main processor to sleep when not in use and wakes it up only when a touch is detected. Granted to Apple Inc in 2012 with 26 claims and 21 forward citations, and it is expected to expire in 2027.
Coverage
What does this patent actually cover?
This patent describes a way to make touchscreens more energy-efficient by creating an autonomous 'sniff' mode. When the screen hasn't been touched for a while, the system disables the main sensor processor and its system clock to save power. During this idle time, dedicated 'auto-scan' logic periodically checks the panel for activity. If a touch is detected, the logic automatically wakes up the main processor to handle the input, ensuring the device remains responsive while minimizing battery drain.
The gap
What does this patent NOT cover?
- Does not cover touchscreens that remain fully powered on at all times.
- Does not cover wake-up methods triggered by physical buttons or external sensors (like accelerometers).
- Does not cover software-based power management that runs entirely on the main CPU without dedicated hardware scan logic.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The system uses a 'sniff' timer to decouple the high-power processor from the low-power sensor monitoring, allowing the screen to 'wake up' the computer rather than the computer constantly 'asking' the screen if it has been touched.
The Patent Drawing
Schematic visualization of the patent's claim structure. Hand-drawn diagrams in progress for each landmark patent.
Where you've seen this
Real-world examples
iPhone and iPad touch input subsystems
Modern smartphone capacitive touch controllers
Battery-efficient tablet interfaces
Why it matters
The bigger picture
Battery life is the primary constraint for mobile devices. By offloading the constant, low-level monitoring of the touchscreen to simple hardware logic, this patent allows the power-hungry main processor to stay in a deep sleep state for much longer, which was essential for the usability of early multi-touch smartphones.
Filed
January 3, 2007
Granted
February 28, 2012
Market context
Who's building on this
Companies in this space
Apple continues to refine these power-management techniques in its custom silicon (A-series and M-series chips). Other major touch controller manufacturers like Synaptics and Broadcom utilize similar autonomous scanning architectures to meet industry standards for low-power operation.
Market impact
This technology became a standard feature in mobile computing, enabling the 'always-on' responsiveness users expect from smartphones without sacrificing battery life. It effectively shifted the design paradigm for touch controllers from passive components to active, intelligent subsystems capable of independent power management.
Claim 1 — Plain English
What this patent covers
This patent describes a way to make touchscreens more energy-efficient by creating an autonomous 'sniff' mode. When the screen hasn't been touched for a while, the system disables the main sensor processor and its system clock to save power. During this idle time, dedicated 'auto-scan' logic periodically checks the panel for activity. If a touch is detected, the logic automatically wakes up the main processor to handle the input, ensuring the device remains responsive while minimizing battery drain.
The clever bit
The system uses a 'sniff' timer to decouple the high-power processor from the low-power sensor monitoring, allowing the screen to 'wake up' the computer rather than the computer constantly 'asking' the screen if it has been touched.
What it does not cover
- Does not cover touchscreens that remain fully powered on at all times.
- Does not cover wake-up methods triggered by physical buttons or external sensors (like accelerometers).
- Does not cover software-based power management that runs entirely on the main CPU without dedicated hardware scan logic.
Patent timeline
Application submitted to the patent office
Application published, typically 18 months after filing
Patent officially issued
Patent enters public domain
PatentBrief Score
Impact Score
Strong
Citation count
27/40
Moderately cited
Claim breadth
17/20
Very broad protection
Recency
5/20
Granted 10–20 years ago
Assignee scale
20/20
Major company or institution
PatentBrief Impact Score — based on citation count, claim breadth, recency, and assignee scale. Not a legal assessment.
Heuristic Value Estimate
What this patent might be worth
$35K – $112K
Midpoint $70K · expired or expiring · industry ×1.6
Heuristic only — blends forward/backward citation counts, claim scope, time remaining, litigation history, and CPC-derived industry baseline. Real valuations need a professional appraisal.
Claim text not yet imported for this patent
The original legal language
Original claims
26 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Wilson, T. J., Vu, M. T., & Krah, C. H. (2012). How Touchscreens Save Battery by Sleeping Between Touches (U.S. Patent No. 8,125,456). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/8125456/multi-touch-capacitive-scanning
Auto-generated from the patent record. Double-check author order and the issue date against the official USPTO document before submitting.
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Common Questions
Frequently Asked Questions
What does How Touchscreens Save Battery by Sleeping Between Touches cover?
A power-saving method for touchscreens that puts the main processor to sleep when not in use and wakes it up only when a touch is detected.
Who owns patent US 8125456?
Apple Inc owns this patent, granted in 2012.
When does this patent expire?
This patent is expected to expire on January 3, 2027, when the invention enters the public domain.
What is patent US 8125456 cited by?
This patent has been cited by 21 later patents that build on its ideas.
What problem does this patent solve?
Battery life is the primary constraint for mobile devices. By offloading the constant, low-level monitoring of the touchscreen to simple hardware logic, this patent allows the power-hungry main processor to stay in a deep sleep state for much longer, which was essential for the usability of early multi-touch smartphones.
What does this patent NOT cover?
Does not cover touchscreens that remain fully powered on at all times.
Same assignee
More from Apple Inc
Patent monitoring