The ranked dataset covers 100 assignees, with the leading filer holding 435 records against 144 for the fifth-ranked assignee and 66 for the tenth. That is a steep concentration at the very top, but the top five combined still account for only 30.6% of all 4,744 records, so the majority of the field is held by a long tail of smaller filers. Anyone doing freedom-to-operate work should check both the leader’s portfolio and the long tail, since narrow claims from smaller filers can still block specific implementations.

Filings rose from 287 in 2017 to a peak of 648 in 2022, then fell to 353 by 2024, a -37% change across that three-year span. Because patent publication typically lags the actual filing date by around 18 months, the lower counts shown for 2025 and 2026 are incomplete rather than evidence of a real slowdown. The safest read is that filing activity has passed its 2022 peak but the current trajectory will not be clear until those later years finish publishing.

Just over half of all 4,744 records, 50.9%, carry a G01S classification for radar, sonar and positioning, reflecting how central lidar and ranging applications have become to this field. Semiconductor-device claims under H01L follow at 29.3%, and pictorial-communication claims under H04N sit at 17.0%. Since a single record can carry several IPC codes, these shares overlap rather than summing to 100%, so they describe where claim density sits, not a clean split of the field.