Superconducting cryo module
US-2026038761-A1 · Feb 5, 2026 · US
Electron guns using field-emission, photo-emission, or secondary-emission electron source
Electron guns using field-emission, photo-emission, or secondary-emission electron source · Cooperative Patent Classification (CPC)
Electric circuits, power, telecommunications, and semiconductors.
Related technology areas
Mapped technology topics for this CPC code.
| Metric | Value |
|---|---|
| CPC code | H01J29/481 |
| Official title | {Electron guns using field-emission, photo-emission, or secondary-emission electron source} |
| Display label | Electron guns using field-emission, photo-emission, or secondary-emission electron source |
| Total patents | 34 |
Filing trend
Year-over-year patent counts classified under this CPC code.
Filing activity over the last five years is stable.
| Year | Patents |
|---|---|
| 2015 | 9 |
| 2016 | 5 |
| 2017 | 5 |
| 2018 | 2 |
| 2019 | 2 |
| 2020 | 2 |
| 2021 | 2 |
| 2022 | 3 |
| 2023 | 1 |
| 2024 | 2 |
| 2026 | 1 |
Representative patents
Representative publications under this CPC code from precomputed stats, or recent filings when stats are unavailable.
Electron emission methods to generate electron beams with a narrow energy distribution
US-2024145204-A1 · May 2, 2024 · US
Regulated charged particle beam emitter systems and methods
US-11899159-B2 · Feb 13, 2024 · US
Electron source based on field emission and production process for same
US-2023005695-A1 · Jan 5, 2023 · US
Electron source and electron source unit
US-11476075-B2 · Oct 18, 2022 · US
Field emission device
US-11342153-B2 · May 24, 2022 · US
Electron source and electron source unit
US-2022157551-A1 · May 19, 2022 · US
Field emission device
US-2021305002-A1 · Sep 30, 2021 · US
Electron gun and apparatus incorporating the same
US-10916399-B1 · Feb 9, 2021 · US
Radial radio frequency (RF) electron guns
US-10854417-B1 · Dec 1, 2020 · US
Regulated Charged Particle Beam Emitter Systems and Methods
US-2020321182-A1 · Oct 8, 2020 · US
Tunable quantum confinement and quantum dot photocathode
US-10395882-B1 · Aug 27, 2019 · US
Compact modular cathode
US-10319554-B2 · Jun 11, 2019 · US
Emitter, electron gun using emitter, electronic apparatus using electron gun, and method of producing emitter
US-10026585-B2 · Jul 17, 2018 · US
Emitter, Electron Gun Using Emitter, Electronic Apparatus Using Electron Gun, and Method of Producing Emitter
US-2018019091-A1 · Jan 18, 2018 · US
Compact modular cathode
US-2017365438-A1 · Dec 21, 2017 · US
Variable field emission device
US-9824845-B2 · Nov 21, 2017 · US
Electron emission device and transistor provided with the same
US-9779906-B2 · Oct 3, 2017 · US
Electron emission device and transistor provided with the same
US-2017243712-A1 · Aug 24, 2017 · US
Electron gun, charged particle gun, and charged particle beam apparatus using electron gun and charged particle gun
US-9570268-B2 · Feb 14, 2017 · US
Frequently asked questions
Answers are generated from the same data shown on this page.
- What is CPC H01J29/481?
- CPC H01J29/481 is the Cooperative Patent Classification code for “Electron guns using field-emission, photo-emission, or secondary-emission electron source.”
- How many patents are filed under CPC H01J29/481 (Electron guns using field-emission, photo-emission, or secondary-emission electron source)?
- Our database includes 34 publications tagged with this CPC code.
- Is patent activity under CPC H01J29/481 growing?
- Publication counts under this code: 1 in 2023 vs 2 in 2024 (latest complete years).