A global shutter pixel captures every row of an image sensor at the same instant, rather than scanning row by row as rolling shutter designs do, which eliminates motion artefacts on fast-moving subjects. The storage node is the on-pixel element that holds the collected charge or voltage between exposure and readout, and its design determines how much stray light leaks into it during that hold period. Most of the patent activity in this dataset — reflected in the 58.2% of the 562 records tagged under H01L — centres on shielding that storage node so parasitic light sensitivity does not corrupt the held signal.

The assignee ranking in this dataset covers 76 companies, with the leader holding 71 of the 562 records and the field showing real concentration at the top: the top five assignees combined account for 46.1% of all records, and the top ten for 63.7%. That leaves a long tail of companies with only a handful of filings each. Recent-year momentum data shows several of the largest historical filers, including major imaging and semiconductor names, recording zero filings in the latest tracked year, consistent with the broader 18-month publication lag rather than necessarily a slowdown in R&D.

Filings peaked at 67 in 2018 and the 2021-to-2024 window shows a further 21% decline (19 down to 15), which is the most recent period that can be read as a complete trend given publication lag. This pattern typically reflects a claim space where the core shielding and storage-node architectures were staked out early, pushing later filers toward narrower, more specific variations rather than foundational claims. It does not necessarily mean R&D activity itself has slowed, since design work on emerging variants can continue without generating comparably high filing volumes.

The thinnest subclasses in this dataset are H10F (photovoltaic and light-sensitive devices, 3.6% of the 562 records) and G01S (radar, sonar and positioning, 6.4%), both far below the 58.2% and 69.4% seen in the core H01L and H04N subclasses. These branches show little concentration at the top of the assignee ranking, meaning storage-node designs aimed at ranging or time-of-flight applications, or built around non-standard light-sensitive device structures, remain comparatively under-claimed. That combination of low density and low concentration is the practical signature of open claim space.

US20120273854A1, assigned to Aptina Imaging Corporation and published in 2012, claims a specific series-connected transistor chain (anti-blooming, storage-gate, transfer) paired with a storage-node diode shielded by an extended photodiode region and an overlying metallic layer. Any new design using that exact shielding geometry and transistor sequence sits inside the claim scope and needs a design-around. Alternatives that use a different shielding mechanism or transistor ordering are the usual route taken to avoid direct overlap, and a formal claim chart is the only reliable way to confirm freedom to operate for a specific design.