How Devices Detect Touch Using Heat Signatures
This patent describes a system that uses a thermal camera to detect when two objects, like a finger and a screen, touch by looking for a specific temperature change at their contact point.
Original patent title: “Method and Device for Detecting a Touch Between a First Object and a Second Object”
This patent describes a system that uses a thermal camera to detect when two objects, like a finger and a screen, touch by looking for a specific temperature change at their contact point. Owned by Apple with 25 claims and 1 forward citation, and it is expected to expire in 2040.
Coverage
What does this patent actually cover?
The patent describes a system that uses a thermal camera to detect when a "first object" (like a finger) touches a "second object" (like a display). The system first takes a thermal image of both objects and determines their individual temperatures. A touch is detected when the system finds pixels in the thermal image that show a "third temperature" exactly where the two objects meet (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 31). This "third temperature" is different from the individual object temperatures, indicating contact. For example, if a warm hand touches a cooler display, the system would identify a distinct warm spot on the display in the thermal image. The system then uses this detected touch and its position on the display to provide user input, such as interacting with an application (Claim 31).
The gap
What does this patent NOT cover?
- Does not cover touch detection methods that do not rely on thermal imaging.
- Does not cover systems that detect touch without identifying a distinct "third temperature" at the contact point (ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 31).
- Does not cover touch detection where the two objects have the same temperature, as the method relies on a temperature difference.
- Does not cover touchscreens that use electrical capacitance, pressure sensors, or optical sensors to detect contact.
- Does not cover systems that only detect the presence of an object without specifically identifying a touch based on a temperature change.
These exclusions are unique to PatentBrief — derived from the actual claim language, not patent-office boilerplate.
Key facts
What made this novel
The noveltynoveltyThe requirement that an invention be different from anything publicly known before its priority date.Read more → lies in using thermal imaging to specifically identify a touch event by detecting a distinct "third temperature" at the precise point of contact between two objects that have different initial temperatures. This goes beyond just seeing heat; it's about identifying the interaction through a localized temperature anomaly.
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
Future augmented reality (AR) displays
Interactive surfaces in industrial or medical settings
Devices requiring touch input while wearing gloves
Advanced human-computer interfaces for specialized tasks
Why it matters
The bigger picture
This technology could enable new ways for users to interact with devices, especially in environments where traditional touchscreens might be difficult to use, like with gloves or through certain materials. It could also provide more precise or nuanced input by detecting the specific area of contact and even aspects like which part of a user's hand is touching, as suggested by ClaimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → 40.
Filed
December 23, 2020
Market context
Who's building on this
Companies in this space
Apple, as the assigneeassigneeThe entity that owns the patent — usually the inventor's employer or a company.Read more →, is likely exploring or developing this technology for future products, potentially in areas like augmented reality or advanced human-computer interfaces. Other companies working on advanced sensing technologies and thermal imaging, such as FLIR Systems, could also be relevant in this space.
Market impact
This patent suggests a potential future direction for touch interaction, moving beyond traditional capacitive or resistive screens. If widely adopted, it could enable new types of interactive surfaces and devices, especially where conventional touch methods are impractical. It could also lead to more robust and versatile user interfaces in various environments, offering new possibilities for product design and user experience.
Claim 1 — Plain English
What this patent covers
The patent describes a system that uses a thermal camera to detect when a "first object" (like a finger) touches a "second object" (like a display). The system first takes a thermal image of both objects and determines their individual temperatures. A touch is detected when the system finds pixels in the thermal image that show a "third temperature" exactly where the two objects meet (Claim 31). This "third temperature" is different from the individual object temperatures, indicating contact. For example, if a warm hand touches a cooler display, the system would identify a distinct warm spot on the display in the thermal image. The system then uses this detected touch and its position on the display to provide user input, such as interacting with an application (Claim 31).
The clever bit
The novelty lies in using thermal imaging to specifically identify a touch event by detecting a distinct "third temperature" at the precise point of contact between two objects that have different initial temperatures. This goes beyond just seeing heat; it's about identifying the interaction through a localized temperature anomaly.
What it does not cover
- Does not cover touch detection methods that do not rely on thermal imaging.
- Does not cover systems that detect touch without identifying a distinct "third temperature" at the contact point (Claim 31).
- Does not cover touch detection where the two objects have the same temperature, as the method relies on a temperature difference.
- Does not cover touchscreens that use electrical capacitance, pressure sensors, or optical sensors to detect contact.
- Does not cover systems that only detect the presence of an object without specifically identifying a touch based on a temperature change.
Patent timeline
Application submitted to the patent office
Patent enters public domain
PatentBrief Score
Impact Score
Moderate
Citation count
6/40
Early citations
Claim breadth
17/20
Very broad protection
Recency
0/20
Older than 20 years
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
$62K – $200K
Midpoint $125K · 14.4 yr remaining · 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
25 claims as filed with the patent office.
Concepts involved
Citations
Patent lineage
Cite this patent
Kurz, D. How Devices Detect Touch Using Heat Signatures (U.S. Patent No. 20,210,117,042). U.S. Patent and Trademark Office. https://patentbrief.org/patent/us/20210117042/method-and-device-for-detecting-a-touch-between-a-first-object-and-a-second-obje
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 Devices Detect Touch Using Heat Signatures cover?
This patent describes a system that uses a thermal camera to detect when two objects, like a finger and a screen, touch by looking for a specific temperature change at their contact point.
Who owns patent US 20210117042?
This patent is owned by Apple.
When does this patent expire?
This patent is expected to expire on December 23, 2040, when the invention enters the public domain.
What is patent US 20210117042 cited by?
This patent has been cited by 1 later patents that build on its ideas.
What problem does this patent solve?
This technology could enable new ways for users to interact with devices, especially in environments where traditional touchscreens might be difficult to use, like with gloves or through certain materials. It could also provide more precise or nuanced input by detecting the specific area of contact and even aspects like which part of a user's hand is touching, as suggested by Claim 40.
What does this patent NOT cover?
Does not cover touch detection methods that do not rely on thermal imaging.
Patent monitoring