Time-of-Flight Sensor Patents

Time-of-flight (ToF) sensor patents cover direct/indirect-ToF innovations; SPAD/detector innovations; VCSEL/illumination innovations; and depth-computation and application innovations — with IP held by image-sensor and depth-sensing majors (in a field measuring distance and 3D depth by timing light). WHY TIME-OF-FLIGHT SENSORS: a ToF sensor measures DISTANCE by timing how long a light pulse (usually infrared) takes to travel to an object and reflect BACK — and an array of such measurements produces a 3D DEPTH MAP of a scene; this enables smartphone FACE ID/depth, AR/VR spatial mapping, gesture control, robotics/drones, automotive LIDAR, and machine vision — a foundational 3D-sensing technology now in billions of devices. There are two main types: DIRECT ToF (dToF — time the pulse round-trip directly; longer range/accuracy, used in lidar) and INDIRECT ToF (iToF — measure the phase shift of modulated light; higher resolution, shorter range). MAJOR HOLDERS: SONY (stacked SPAD/depth sensors), STMICROELECTRONICS (FlightSense), INFINEON (pmd iToF), AMS OSRAM, APPLE (Face ID dot projector + LiDAR scanner), plus lidar/depth players. Direct/indirect ToF, SPAD/detectors, VCSEL/illumination, depth computation, and applications are the core ToF patent domains — and SPAD detectors, illumination, depth algorithms, and applications are the open whitespace.

Direct-ToF (dToF) innovations; indirect-ToF (iToF) innovations; SPAD/detector innovations; and VCSEL/illumination innovations represent core ToF patent domains — and the timing method, the photon detector, and the light source are the foundational, high-value capabilities. DIRECT-ToF (dToF) PATENTS: measuring the pulse's round-trip TIME directly (high accuracy, longer range — used in automotive LIDAR and Apple's LiDAR scanner) — requiring FAST detectors and picosecond TIMING circuitry (time-to-digital converters), histogramming, and pulse design; dToF methods are core, high-value IP (dToF enables long-range/lidar). INDIRECT-ToF (iToF) PATENTS: measuring the PHASE SHIFT of continuously MODULATED light to infer distance (higher pixel RESOLUTION, shorter range — used in depth cameras/Face-ID-style) — modulation schemes, phase-measurement pixels, and resolving phase ambiguity; iToF methods are core, high-value IP (iToF gives dense depth maps). SPAD / DETECTOR PATENTS: the key detector — SINGLE-PHOTON AVALANCHE DIODES (SPADs) and arrays that detect even single returning PHOTONS with picosecond timing (essential for dToF), plus STACKED/back-illuminated sensor fabrication (Sony) integrating SPADs with timing circuits; SPAD/detector methods are core, high-value IP (sensitive, fast, small-pixel detectors are foundational — and a key Sony/STMicro strength). VCSEL / ILLUMINATION PATENTS: the infrared light SOURCE — VCSEL (vertical-cavity surface-emitting laser) arrays, DOT projectors (for structured patterns/Face ID), beam shaping, and crucially EYE-SAFETY (high-power IR must be eye-safe); VCSEL/illumination methods are high-value IP (the illuminator's power/efficiency/safety shapes range and performance). Direct/indirect ToF, SPAD detectors, and VCSEL illumination are the highest-value core IP because the timing method, photon detector, and light source together determine a ToF sensor's range, resolution, and performance.

Depth-computation innovations; multipath/ambient-light-correction innovations; application innovations; and integration/power innovations represent additional ToF patent domains — and turning raw timing/phase into accurate depth, handling real-world error sources, and the applications are where usable performance and value are won. DEPTH-COMPUTATION PATENTS: the algorithms turning raw timing (dToF histograms) or phase (iToF) measurements into accurate, dense DEPTH maps — depth estimation, denoising, fusion (with RGB cameras for RGB-D), and confidence; depth-computation methods are high-value IP (the processing that produces usable depth — mind §101, claim concrete sensor-tied technical methods). MULTIPATH / AMBIENT-LIGHT-CORRECTION PATENTS: real-world error sources — MULTIPATH (light bouncing off multiple surfaces corrupts depth), AMBIENT LIGHT (sunlight swamps the signal outdoors), and motion — methods CORRECTING multipath, rejecting ambient light, and handling interference between multiple ToF devices; multipath/ambient-correction methods are high-value, distinctive IP (real-world robustness — especially outdoors/automotive — is a key technical challenge). APPLICATION PATENTS: specific applications — FACE ID/biometrics (3D face authentication), AR/VR (depth/spatial mapping/occlusion), GESTURE recognition, robotics/drones (obstacle avoidance), AUTOMOTIVE lidar, and machine vision; application-specific ToF methods are high-value IP (the application drives the design — biometrics needs security, automotive needs range/safety). INTEGRATION / POWER PATENTS: integrating sensor + illuminator + processing into a compact, LOW-POWER module (critical for phones/wearables), and module/optical packaging; integration/power methods are valuable (SWaP/cost for consumer devices). Depth computation, multipath/ambient correction, applications, and integration/power are the highest-value application IP because accurate depth, real-world robustness, application fit, and compact low-power integration are exactly what make ToF sensors useful in products.

Time-of-flight sensor startup IP strategy must navigate Sony/STMicro/Infineon/ams/Apple's strong portfolios (the image-sensor and depth-sensing giants hold deep SPAD/detector/iToF IP, and the consumer ToF market is dominated by them), decades of ToF/lidar/imaging prior art (ToF is mature in consumer/automotive — the SPAD advances, real-world robustness, and application-specific designs are the novelty), the §101 (depth-algorithm) considerations, the hardware-vs-algorithm split (SPAD/sensor/VCSEL hardware is capital-intensive and giant-dominated; depth/multipath ALGORITHMS and application-specific processing are more accessible for startups), the real-world-robustness challenge (multipath/ambient/outdoor — where defensible IP lives), the application focus (Face ID/AR/automotive-lidar each different requirements), the dToF-vs-iToF choice, and a landscape where SPAD detectors, illumination, depth algorithms, robustness, and applications are the durable assets; understand that core ToF and SPAD hardware are giant-dominated, so the durable IP for startups is in depth/multipath/robustness algorithms, application-specific processing, illumination/optics, and any novel detector ideas — with algorithms/robustness and application know-how often the real moat, and that depth accuracy, real-world robustness, power/cost, and application fit matter as much as patents; identify whitespace in robustness algorithms, applications, and illumination. ToF STARTUP IP STRATEGY: DEPTH/MULTIPATH/ROBUSTNESS ALGORITHMS, APPLICATION-SPECIFIC PROCESSING, ILLUMINATION/OPTICS, AND NOVEL DETECTOR IDEAS ARE THE IP: patent depth-computation, multipath/ambient-correction, application-specific processing, illumination/optics, and any novel SPAD/detector designs — claim algorithms as concrete sensor-tied technical methods (mind §101); SENSOR/SPAD HARDWARE IS GIANT-DOMINATED — GO ALGORITHMS/APPLICATIONS: Sony/STMicro/Infineon/ams hold deep SPAD/iToF/detector IP and the consumer market — startups win in depth/multipath ALGORITHMS, robustness, and application-specific processing (lighter, less head-on) or novel illumination/optics; REAL-WORLD ROBUSTNESS (MULTIPATH/AMBIENT) IS WHERE DEFENSIBLE IP LIVES: correcting multipath, rejecting sunlight (outdoor/automotive), and handling device interference are hard, valuable problems — robustness IP is defensible; APPLICATION FOCUS SHAPES IP: Face ID/biometrics (security/3D), AR/VR (dense depth/occlusion), automotive lidar (range/safety — see FMCW/photonic lidar), gesture, robotics — each different requirements/IP; dToF VS iToF IS A CORE CHOICE: dToF (long range/lidar, needs SPAD/timing) vs iToF (high resolution/short range, phase) — different IP and applications; DEPTH-COMPUTATION ALGORITHMS ARE VALUABLE (MIND §101): turning timing/phase into accurate dense depth (and RGB-D fusion) is high-value — claim concrete sensor-integrated methods; ILLUMINATION/EYE-SAFETY/OPTICS IS A NICHE: VCSEL/dot-projector/beam-shaping and eye-safety are valuable; INTEGRATION/POWER FOR CONSUMER: compact low-power modules for phones/wearables matter; ACCURACY/ROBUSTNESS/POWER/APPLICATION MATTER AS MUCH AS PATENTS: depth accuracy, real-world robustness, power/cost, and application fit drive value; WHEN TO PATENT: NOVEL ALGORITHM/DETECTOR/ILLUMINATION/APPLICATION WITH MEASURED PERFORMANCE: file once a method shows measured results (depth accuracy/range/resolution + multipath/ambient robustness + power + frame rate + application performance) — measured depth accuracy/range, real-world robustness, and power are the critical ToF IP metrics; KEY FTO CHECKLIST: Sony (stacked SPAD/depth); STMicro (FlightSense); Infineon (pmd iToF); ams OSRAM; Apple (Face ID/LiDAR); ToF/lidar/imaging prior art; direct ToF (dToF, round-trip timing/TDC/histogram); indirect ToF (iToF, phase/modulation/ambiguity); SPAD/detector/stacked-back-illuminated; VCSEL/dot-projector/illumination/eye-safety; depth computation/RGB-D fusion (§101); multipath/ambient-light/interference correction; applications (Face ID/AR/VR/gesture/robotics/automotive lidar); module integration/power/optics.