H01J 25/52
With an electron space having a shape that does not prevent any
Official title: with an electron space having a shape that does not prevent any electron from moving completely around the cathode or guide electrode
H01J25/52 (With an electron space having a shape that does not prevent any) appears on 147 US grants and 110 published applications in this corpus.
Search patents in H01J- Granted patents
- 147
- Published applications
- 110
- Assignees
- 63
- Inventors
- 250
- Latest grant
- 12 May 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 1 | 0 |
| 1977 | 1 | 0 |
| 1978 | 4 | 0 |
| 1979 | 0 | 0 |
| 1980 | 1 | 0 |
| 1981 | 4 | 0 |
| 1982 | 0 | 0 |
| 1983 | 2 | 0 |
| 1984 | 0 | 0 |
| 1985 | 2 | 0 |
| 1986 | 1 | 0 |
| 1987 | 1 | 0 |
| 1988 | 1 | 0 |
| 1989 | 1 | 0 |
| 1990 | 0 | 0 |
| 1991 | 3 | 0 |
| 1992 | 2 | 0 |
| 1993 | 1 | 0 |
| 1994 | 1 | 0 |
| 1995 | 4 | 0 |
| 1996 | 4 | 0 |
| 1997 | 4 | 0 |
| 1998 | 2 | 0 |
| 1999 | 1 | 0 |
| 2000 | 2 | 0 |
| 2001 | 1 | 2 |
| 2002 | 4 | 3 |
| 2003 | 6 | 5 |
| 2004 | 7 | 16 |
| 2005 | 6 | 9 |
| 2006 | 13 | 5 |
| 2007 | 5 | 4 |
| 2008 | 2 | 4 |
| 2009 | 4 | 6 |
| 2010 | 1 | 2 |
| 2011 | 5 | 9 |
| 2012 | 3 | 4 |
| 2013 | 3 | 4 |
| 2014 | 8 | 6 |
| 2015 | 8 | 3 |
| 2016 | 2 | 3 |
| 2017 | 6 | 2 |
| 2018 | 1 | 0 |
| 2019 | 4 | 3 |
| 2020 | 1 | 1 |
| 2021 | 3 | 4 |
| 2022 | 2 | 5 |
| 2023 | 4 | 3 |
| 2024 | 2 | 1 |
| 2025 | 1 | 5 |
| 2026 | 2 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- Radiotherapy device and microwave source thereof12 May 2026US 12,623,089 B2Shanghai United Imaging Healthcare Co., Ltd.
- Magnetron10 Feb 2026US 12,548,729 B2Hitachi Power Solutions Co., Ltd.
- RF source protection9 Sep 2025US 12,414,221 B2Elekta Limited
- Industrial magnetron15 Oct 2024US 12,119,200 B2Hitachi Power Solutions Co., Ltd.
- Simultaneous wireless information and power transfer device and method based on the modulation of power supply ripple of magnetron11 Jun 2024US 12,009,676 B2Sichuan University
- Electron tube6 Aug 2026US 2026/0229442 A1Nisshinbo Micro Devices Inc.
- Control Circuit And Microwave Generation Device20 Nov 2025US 2025/0357064 A1Guangdong Midea Kitchen Appliances Manufacturing Co., Ltd.
- Compact mode converter waveguide13 Nov 2025US 2025/0349486 A1Varian Medical Systems, Inc.
- Magnetron and Microwave Heating Device10 Jul 2025US 2025/0227822 A1Guangdong Witol Vacuum Electronic Manufacture Co., Ltd.
- Magnetron and Microwave Heating Device10 Jul 2025US 2025/0227823 A1Guangdong Witol Vacuum Electronic Manufacture Co., Ltd.
Most cited
By later US patents
- Magnetron for microwave oven123US 5,294,864 AGoldstar Co., Ltd. · 1994
- High frequency heating apparatus with abnormal condition detection21US 5,001,318 AKabushiki Kaisha Toshiba · 1991
- Magnetron tuning using plasmas18US 6,064,154 ARaytheon Company · 2000
- Magnetron with improved mode separation16US 5,635,797 AHitachi Device Engineering Co., Ltd. · 1997
- Magnetron with reduced dark current15US 5,635,798 AHitachi Electronic Devices Co., Ltd. · 1997