G11B 5/21
The pole pieces being of ferrous sheet metal or other magnetic layers
Official title: the pole pieces being of ferrous sheet metal {or other magnetic layers (G11B5/1871 takes precedence; in thin film G11B5/31)}
G11B5/21 (The pole pieces being of ferrous sheet metal or other magnetic layers) appears on 79 US grants and 17 published applications in this corpus.
Search patents in G11B- Granted patents
- 79
- Published applications
- 17
- Assignees
- 37
- Inventors
- 190
- Latest grant
- 7 Oct 2025
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1978 | 1 | 0 |
| 1979 | 1 | 0 |
| 1980 | 0 | 0 |
| 1981 | 1 | 0 |
| 1982 | 0 | 0 |
| 1983 | 3 | 0 |
| 1984 | 0 | 0 |
| 1985 | 1 | 0 |
| 1986 | 0 | 0 |
| 1987 | 4 | 0 |
| 1988 | 6 | 0 |
| 1989 | 3 | 0 |
| 1990 | 3 | 0 |
| 1991 | 2 | 0 |
| 1992 | 4 | 0 |
| 1993 | 5 | 0 |
| 1994 | 2 | 0 |
| 1995 | 3 | 0 |
| 1996 | 3 | 0 |
| 1997 | 3 | 0 |
| 1998 | 2 | 0 |
| 1999 | 3 | 0 |
| 2000 | 2 | 0 |
| 2001 | 3 | 0 |
| 2002 | 1 | 0 |
| 2003 | 0 | 0 |
| 2004 | 0 | 0 |
| 2005 | 1 | 2 |
| 2006 | 0 | 2 |
| 2007 | 1 | 0 |
| 2008 | 1 | 0 |
| 2009 | 1 | 0 |
| 2010 | 1 | 0 |
| 2011 | 0 | 0 |
| 2012 | 0 | 0 |
| 2013 | 0 | 0 |
| 2014 | 0 | 0 |
| 2015 | 0 | 0 |
| 2016 | 0 | 0 |
| 2017 | 1 | 1 |
| 2018 | 1 | 1 |
| 2019 | 2 | 0 |
| 2020 | 1 | 1 |
| 2021 | 1 | 1 |
| 2022 | 3 | 4 |
| 2023 | 4 | 3 |
| 2024 | 4 | 2 |
| 2025 | 1 | 0 |
By publication year. Applications have been published since 2001.
Recent patents
- Magnetic head and magnetic recording device7 Oct 2025US 12,437,779 B2Kabushiki Kaisha Toshiba
- Magnetic head and magnetic recording device10 Dec 2024US 12,165,676 B2Kabushiki Kaisha Toshiba
- Magnetic head and magnetic recording device3 Sep 2024US 12,080,325 B2Kabushiki Kaisha Toshiba
- Cross track current design for energy assisted magnetic recording23 Jan 2024US 11,881,237 B1Western Digital Technologies, Inc.
- Magnetic head and magnetic recording device9 Jan 2024US 11,869,540 B2Kabushiki Kaisha Toshiba
- Magnetic head and magnetic recording device31 Oct 2024US 2024/0363141 A1Kabushiki Kaisha Toshiba
- Gold-Copper Alloy In A Heat-Assisted Magnetic Recording Writer16 May 2024US 2024/0161772 A1Headway Technologies, Inc.
- Magnetic head and magnetic recording device19 Oct 2023US 2023/0335154 A1Kabushiki Kaisha Toshiba
- Magnetic head and magnetic recording device12 Oct 2023US 2023/0326482 A1Kabushiki Kaisha Toshiba
- Magnetic head and magnetic recording device24 Aug 2023US 2023/0267961 A1Kabushiki Kaisha Toshiba
Most cited
By later US patents
- Apparatus for magnetically recording digital data97US 5,416,651 ASony Corporation · 1995
- Soft magnetic thin film, method for preparing same and magnetic head42US 5,117,321 AFuji Photo Film Co., Ltd. · 1992
- Process for producing a magnetic recording head36US 5,090,111 ACommissariat A L' Energie Atomique · 1992
- Magnetic head incorporating an amorphous magnetic metallic film having a thickness equal to a track width33US 4,535,376 AMatsushita Electric Industrial Co., Ltd. · 1985
- Method for embodying a magnetic head with two magnetic materials33US 5,224,260 ACommissariat A L' Energie Atomique · 1993