H01J 3/021
Electron guns using a field emission, photo emission, or secondary emission electron
Official title: {Electron guns using a field emission, photo emission, or secondary emission electron source}
H01J3/021 (Electron guns using a field emission, photo emission, or secondary emission electron) appears on 812 US grants and 439 published applications in this corpus.
Search patents in H01J- Granted patents
- 812
- Published applications
- 439
- Assignees
- 246
- Inventors
- 1,089
- Latest grant
- 21 Oct 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 2 | 0 |
| 1977 | 0 | 0 |
| 1978 | 0 | 0 |
| 1979 | 0 | 0 |
| 1980 | 0 | 0 |
| 1981 | 0 | 0 |
| 1982 | 2 | 0 |
| 1983 | 0 | 0 |
| 1984 | 1 | 0 |
| 1985 | 2 | 0 |
| 1986 | 1 | 0 |
| 1987 | 8 | 0 |
| 1988 | 8 | 0 |
| 1989 | 3 | 0 |
| 1990 | 5 | 0 |
| 1991 | 8 | 0 |
| 1992 | 13 | 0 |
| 1993 | 21 | 0 |
| 1994 | 18 | 0 |
| 1995 | 20 | 0 |
| 1996 | 39 | 0 |
| 1997 | 37 | 0 |
| 1998 | 63 | 0 |
| 1999 | 68 | 0 |
| 2000 | 57 | 0 |
| 2001 | 37 | 12 |
| 2002 | 48 | 38 |
| 2003 | 34 | 29 |
| 2004 | 33 | 39 |
| 2005 | 26 | 53 |
| 2006 | 25 | 52 |
| 2007 | 23 | 39 |
| 2008 | 27 | 11 |
| 2009 | 29 | 17 |
| 2010 | 17 | 14 |
| 2011 | 14 | 13 |
| 2012 | 10 | 11 |
| 2013 | 11 | 18 |
| 2014 | 11 | 13 |
| 2015 | 16 | 12 |
| 2016 | 11 | 8 |
| 2017 | 11 | 5 |
| 2018 | 4 | 2 |
| 2019 | 8 | 9 |
| 2020 | 8 | 4 |
| 2021 | 6 | 12 |
| 2022 | 8 | 9 |
| 2023 | 4 | 9 |
| 2024 | 6 | 4 |
| 2025 | 9 | 1 |
| 2026 | 0 | 5 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Electron beam devices with semiconductor ultraviolet light source21 Oct 2025US 12,451,314 B2Gaska Consulting, LLC
- Electron beam applicator, and electron beam emission method in electron beam applicator15 Jul 2025US 12,362,128 B2Photo electron Soul Inc.
- Electron gun and electron beam application device17 Jun 2025US 12,334,297 B2Hitachi High-Tech Corporation
- Field emission cathode device and method for forming a field emission cathode device15 Apr 2025US 12,278,078 B2NCX Corporation
- Pulsed generator of electrically charged particles and method for using a pulsed generator of electrically charged particles15 Apr 2025US 12,278,082 B2Commissariat A L' Energie Atomique Et Aux Energies Alternatives
- Field emission source for ion mobility spectrometry23 Jul 2026US 2026/0210910 A1Verily Life Sciences LLC
- Electron emission source18 Jun 2026US 2026/0171342 A1Infovion Inc.
- Electron source7 May 2026US 2026/0128249 A1Kabushiki Kaisha Toshiba
- Electron beam devices with semiconductor ultraviolet light source19 Feb 2026US 2026/0051451 A1Gaska Consulting, LLC
- Superconducting cryo module5 Feb 2026US 2026/0038761 A1Mitsubishi Heavy Industries Machinery Systems, Ltd.
Most cited
By later US patents
- Split collector vacuum field effect transistor357US 5,012,153 A1991
- Vertical microelectronic field emission devices312US 5,475,280 AMcnc · 1995
- Electron emission device215US 4,904,895 ACanon Kabushiki Kaisha · 1990
- Field emission device160US 4,663,559 A1987
- Flat panel field emission display apparatus155US 5,283,500 AAT&T Bell Laboratories · 1994