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Kanagawa, Japan

D + M Holdings Inc.

USPTO Granted Patents = 73

% Expired Patents = 6.8

EPO Patents = 38

Trademarks = 15

Forward Citations = 642

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69 inventors (with patents filed for the assignee):

Nicholas J Murrells (8 out of 12 patents)

Martin Richard Wachter (7 out of 8 patents)

Brendon Stead (6 out of 6 patents)

4. Katsuyoshi Takeno (6 out of 6 patents)

5. Shunichi Tani (4 out of 4 patents)

6. Peter Celinski (3 out of 12 patents)

7. Anders Brogestam (3 out of 3 patents)

8. Max Gordon Ramsay (3 out of 10 patents)

9. Yoshinari Fukushima (3 out of 3 patents)

10. Kazuhiro Onizuka (3 out of 3 patents)

11. Syunji Usui (3 out of 3 patents)

12. Yoshiharu Imahama (3 out of 4 patents)

13. Reiko Ito (3 out of 3 patents)

14. Sho Kodama (2 out of 45 patents)

15. Christopher Commons (2 out of 5 patents)

Core Competencies:

Audio Device

Multi-Channel Audio System

Wireless Speaker

AV Amplifier

Signal Processing

Text-to-Speech

Audio Playback

Networked Rendering

Content Transmission

Headphones

Microphone Stand

Projector Apparatus

73 patents: Sort by Forward Citations

1. 12445778 - AV amplifier (2025-10-14),

2. 12436730 - Audio device (2025-10-07),

3. 12375541 - System and method for synchronizing networked rendering devices (2025-07-29),

4. 12356160 - Multi-channel audio system, multi-channel audio device, program, and multi-channel audio playback method (2025-07-08),

5. 12342147 - Audio device, audio system, and computer-readable program (2025-06-24),

6. 12245009 - Wireless audio system, wireless speaker, and group joining method for wireless speaker (2025-03-04),

7. 12231873 - Operation terminal, audio device, audio system, and computer-readable program (2025-02-18),

8. 12212913 - Earphone device (2025-01-28),

9. 12170881 - Multichannel audio system, acoustic profile information generating device, wireless recording playback device, program, and method for generating acoustic profile information (2024-12-17),

10. 12020686 - System providing expressive and emotive text-to-speech (2024-06-25),

11. 11902616 - Audio-visual device (2024-02-13),

12. 11792574 - AV amplifier (2023-10-17),

13. 11381958 - Remote system configuration using audio ports (2022-07-05),

14. 11315561 - Audio device and computer readable program (2022-04-26),

15. RE48946 - Systems and methods for providing a media playback in a networked environment (2022-02-21),

Company Overview

D + M Holdings Inc. is a prominent player in the audio systems industry, headquartered in Kanagawa, Japan. The company specializes in the development and manufacturing of high-quality audio devices, including multi-channel audio systems, wireless speakers, and AV amplifiers. With a strong focus on signal processing and audio playback technologies, D + M Holdings is dedicated to enhancing the listening experience through innovative solutions. Their expertise extends to networked rendering and text-to-speech applications, positioning them as a leader in audio technology.

Profile summary synthesized from public USPTO records and patent filings.

Company Badge

USPTO Data Jan 1 1976 - Oct 6 2026

73 Patents

#49 in Kanagawa

#1,377 in Japan

#10,256 in the World

Kanagawa, Japan

D + M Holdings Inc.

Forward Citations = 642

69 inventors:

Nicholas J Murrells (8 out of 12 patents)

Martin Richard Wachter (7 out of 8 patents)

Brendon Stead (6 out of 6 patents)

4. Katsuyoshi Takeno (6 out of 6 patents)

5. Shunichi Tani (4 out of 4 patents)

IDiyas Innovation Intelligence. (2026). Company Patent Portfolio: D + M Holdings Inc.. Retrieved from https://idiyas.com/company/d-plus-m-holdings

Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile

Data Sources: USPTO Patent Grant XML, Patent Center, EPO & CIPO • Normalized by IDiyas Innovation Graph. Methodology & provenance architecturePlease report any incorrect information to [email protected]

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