H04Q 5/12
Using combinations of frequencies
Official title: using combinations of frequencies
H04Q5/12 (Using combinations of frequencies) appears on 2 US grants and 0 published applications in this corpus.
Search patents in H04Q- Granted patents
- 2
- Published applications
- 0
- Assignees
- 1
- Inventors
- 1
- Latest grant
- 21 Sep 1993
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1992 | 1 | 0 |
| 1993 | 1 | 0 |
By publication year. Applications have been published since 2001.
Recent patents
- Telephone answering system and apparatus for direct caller selection of a party line extension21 Sep 1993US 5,247,570 AProduct Engineering & Manufacturing, Inc.
- Telephone answering system and apparatus for direct caller selection of a party line extension4 Feb 1992US 5,086,458 AProduct Engineering & Manufacturing, Inc.
No published applications in this class yet.
Most cited
By later US patents
- Telephone answering system and apparatus for direct caller selection of a party line extension33US 5,086,458 AProduct Engineering & Manufacturing, Inc. · 1992
- Telephone answering system and apparatus for direct caller selection of a party line extension4US 5,247,570 AProduct Engineering & Manufacturing, Inc. · 1993