- All sections
- H - Electricity
- H04M - Telephonic communication
- H04M 19/04 - Current supply arrangements for telephone systems providing ringing current or supervisory tones, e.g. dialling tone or busy tone the ringing-current being generated at the substations
Patent holdings for IPC class H04M 19/04
Total number of patents in this class: 726
10-year publication summary
|
123
|
103
|
106
|
92
|
62
|
45
|
25
|
20
|
17
|
12
|
| 2016 | 2017 | 2018 | 2019 | 2020 | 2021 | 2022 | 2023 | 2024 | 2025 |
Principal owners for this class
| Owner |
All patents
|
This class
|
|---|---|---|
| Apple Inc. | 55387 |
84 |
| Samsung Electronics Co., Ltd. | 147501 |
62 |
| Huawei Technologies Co., Ltd. | 113689 |
33 |
| Sony Ericsson Mobile Communications AB | 1755 |
23 |
| Digital Reef, Inc. | 23 |
21 |
| Qualcomm Incorporated | 86346 |
18 |
| Sony Corporation | 30936 |
16 |
| Kyocera Corporation | 13909 |
16 |
| Google LLC | 42540 |
13 |
| Microsoft Technology Licensing, LLC | 53891 |
12 |
| Cerner Innovation, Inc. | 1187 |
11 |
| Immersion Corporation | 527 |
11 |
| LG Electronics Inc. | 73531 |
10 |
| AT&T Intellectual Property I, L.P. | 9576 |
10 |
| Nokia Technologies Oy | 18229 |
10 |
| Intel Corporation | 47143 |
9 |
| Guangdong Oppo Mobile Telecommunications Corp., Ltd. | 21188 |
9 |
| Malikie Innovations Limited | 7079 |
9 |
| Nokia Corporation | 5566 |
8 |
| Mitsumi Electric Co., Ltd. | 1090 |
8 |
| Other owners | 333 |