It is concentrated at the top but not monopolised: the top 5 of 51 ranked assignees hold 101 of 155 records in scope, or 65.2%. The top 10 push that to 93.5%, meaning the remaining 41 ranked assignees split roughly 6.5% of the field between them. This pattern is typical of a technical niche anchored by a handful of research institutions and one or two instrument makers, with a long tail of single- or few-filing entrants rather than a broad competitive middle.

Filing peaked at 24 records in 2023 and eased to 13 in 2024, a documented -38% change from the 2021 level of 21 records. However, publication typically lags filing by around 18 months, so 2025 and 2026 figures in any dataset will look artificially low simply because not all filings from those years have published yet. The honest read is a cooling from a 2023 peak, not a confirmed collapse in activity.

This landscape is scoped specifically to phase contrast and contrast transfer function methods combined with practical failure-mode language such as charging drift, alignment stability and hole-free plate design. That is narrower than electron microscopy broadly, which also covers detectors, sample preparation, and unrelated imaging modes. The IPC mix here — nearly half the records touching C07K peptide claims — shows this specific niche leans heavily toward biological sample applications rather than general instrumentation.