H04Q 1/45
Using multi-frequency signalling
Official title: using multi-frequency signalling (H04Q1/46 takes precedence)
H04Q1/45 (Using multi-frequency signalling) appears on 469 US grants and 153 published applications in this corpus.
Search patents in H04Q- Granted patents
- 469
- Published applications
- 153
- Assignees
- 233
- Inventors
- 768
- Latest grant
- 11 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 24 | 0 |
| 1977 | 18 | 0 |
| 1978 | 11 | 0 |
| 1979 | 9 | 0 |
| 1980 | 12 | 0 |
| 1981 | 6 | 0 |
| 1982 | 10 | 0 |
| 1983 | 10 | 0 |
| 1984 | 6 | 0 |
| 1985 | 6 | 0 |
| 1986 | 12 | 0 |
| 1987 | 11 | 0 |
| 1988 | 5 | 0 |
| 1989 | 9 | 0 |
| 1990 | 8 | 0 |
| 1991 | 2 | 0 |
| 1992 | 9 | 0 |
| 1993 | 12 | 0 |
| 1994 | 14 | 0 |
| 1995 | 15 | 0 |
| 1996 | 10 | 0 |
| 1997 | 9 | 0 |
| 1998 | 15 | 0 |
| 1999 | 17 | 0 |
| 2000 | 15 | 0 |
| 2001 | 11 | 5 |
| 2002 | 14 | 23 |
| 2003 | 14 | 16 |
| 2004 | 18 | 20 |
| 2005 | 13 | 9 |
| 2006 | 15 | 5 |
| 2007 | 13 | 14 |
| 2008 | 5 | 6 |
| 2009 | 10 | 6 |
| 2010 | 10 | 7 |
| 2011 | 9 | 11 |
| 2012 | 8 | 3 |
| 2013 | 14 | 3 |
| 2014 | 10 | 5 |
| 2015 | 10 | 4 |
| 2016 | 3 | 2 |
| 2017 | 2 | 1 |
| 2018 | 2 | 3 |
| 2019 | 4 | 1 |
| 2020 | 2 | 3 |
| 2021 | 3 | 1 |
| 2022 | 1 | 2 |
| 2023 | 0 | 0 |
| 2024 | 1 | 2 |
| 2025 | 0 | 0 |
| 2026 | 2 | 1 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Subgroups
Granted patents
Recent patents
- System, method, and apparatus for detecting call interception11 Aug 2026US 12,707,265 B2University of Florida Research Foundation, Inc.
- Call classification through analysis of DTMF events5 May 2026US 12,621,382 B2Pindrop Security, Inc.
- Call classification through analysis of DTMF events18 Jun 2024US 12,015,731 B2Pindrop Security, Inc.
- Call classification through analysis of DTMF events12 Jul 2022US 11,388,490 B2Pindrop Security, Inc.
- Remote device interface and telephone entry system28 Dec 2021US 11,210,876 B2Alarm.com Incorporated
- Call classification through analysis of dtmf events17 Sep 2026US 2026/0281227 A1Pindrop Security, Inc.
- System, method, and apparatus for detecting call interception19 Dec 2024US 2024/0422545 A1University of Florida Research Foundation, Inc.
- Call classification through analysis of dtmf events26 Sep 2024US 2024/0323270 A1Pindrop Security, Inc.
- Call classification through analysis of dtmf events20 Oct 2022US 2022/0337924 A1Pindrop Security, Inc.
- Remote device interface and telephone entry system7 Apr 2022US 2022/0108573 A1Alarm.com Incorporated
Most cited
By later US patents
- Telephone system for connecting a customer to a supplier of goods744US 4,757,267 AApplied Telematics, Inc. · 1988
- Call routing based on the caller's mood398US 6,411,687 B1Mitel Knowledge Corporation · 2002
- Method and apparatus for telephonically accessing and navigating the internet268US 5,953,392 ANetphonic Communications, Inc. · 1999
- Speech encoding in a client server system250US 6,594,347 B1International Business Machines Corporation · 2003
- Information storage device for storing personal identification information232US 5,825,871 ASmart Tone Authentication, Inc. · 1998