Method of operating a charged particle gun, charged particle gun, and charged particle beam device
US-10861666-B1 · Dec 8, 2020 · US
Electron guns using a field emission, photo emission, or secondary emission electron source
Electron guns using a 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 | H01J3/021 |
| Official title | {Electron guns using a field emission, photo emission, or secondary emission electron source} |
| Display label | Electron guns using a field emission, photo emission, or secondary emission electron source |
| Total patents | 90 |
Filing trend
Year-over-year patent counts classified under this CPC code.
Filing activity over the last five years is stable.
| Year | Patents |
|---|---|
| 2015 | 18 |
| 2016 | 13 |
| 2017 | 14 |
| 2018 | 5 |
| 2019 | 8 |
| 2020 | 9 |
| 2021 | 4 |
| 2022 | 7 |
| 2023 | 5 |
| 2024 | 1 |
| 2025 | 4 |
| 2026 | 2 |
Representative patents
Representative publications under this CPC code from precomputed stats, or recent filings when stats are unavailable.
Field emission device and field emission method
US-10651001-B2 · May 12, 2020 · US
Field emission device and field emission method
US-2019333730-A1 · Oct 31, 2019 · US
Field emission device with ground electrode
US-10438765-B2 · Oct 8, 2019 · US
Electron emission device and method for manufacturing the same
US-2019304732-A1 · Oct 3, 2019 · US
System and Method for Photocathode Illumination Inspection
US-2019295804-A1 · Sep 26, 2019 · US
Optical modulation of on-chip thermionic emission using resonant cavity coupled electron emitters
US-10403484-B2 · Sep 3, 2019 · US
Tunable charged particle vortex beam generator and method
US-2019259561-A1 · Aug 22, 2019 · US
Electron photoemission with tunable excitation and transport energetics
US-10381187-B1 · Aug 13, 2019 · US
Apparatus for aging field emission device and aging method thereof
US-2019080871-A1 · Mar 14, 2019 · US
Optical modulation of on-chip thermionic emission using resonant cavity coupled electron emitters
US-2018301324-A1 · Oct 18, 2018 · US
Applications of graphene grids in vacuum electronics
US-10056219-B2 · Aug 21, 2018 · US
Electron source, X-ray source and device using the X-ray source
US-10014148-B2 · Jul 3, 2018 · US
Apparatus for generating x-ray radiation in an external magnetic field
US-9960003-B2 · May 1, 2018 · US
Apparatus for generating x-ray radiation in an external magnetic field
US-2018019088-A1 · Jan 18, 2018 · US
Detecting system based on terahertz wave
US-9852871-B1 · Dec 26, 2017 · US
Detecting system based on terahertz wave
US-2017352516-A1 · Dec 7, 2017 · US
Tera Hertz reflex klystron
US-9837241-B2 · Dec 5, 2017 · US
Applications of Graphene Grids in Vacuum Electronics
US-2017323755-A1 · Nov 9, 2017 · US
Electron source, x-ray source and device using the x-ray source
US-2017162359-A1 · Jun 8, 2017 · US
Frequently asked questions
Answers are generated from the same data shown on this page.
- What is CPC H01J3/021?
- CPC H01J3/021 is the Cooperative Patent Classification code for “Electron guns using a field emission, photo emission, or secondary emission electron source.”
- How many patents are filed under CPC H01J3/021 (Electron guns using a field emission, photo emission, or secondary emission electron source)?
- Our database includes 90 publications tagged with this CPC code.
- Is patent activity under CPC H01J3/021 growing?
- Publication counts under this code: 1 in 2024 vs 4 in 2025 (latest complete years).