Tokai, Japan

Toshiaki Okuyama

This inventor holds 55 USPTO granted patents and 3 EPO patents, primarily in Induction Motor Control (CPC class 3188). Top assignees: Hitachi, Ltd., Hitachi Automotive Engineering Co., Ltd., Hitachi Industrial Equipment Systems Co., Ltd.. Active years: 1976-2011.

IDiyas Innovation Intelligence. (2026). Inventor Profile: Toshiaki Okuyama. Retrieved from https://idiyas.com/inventor/toshiaki-okuyama

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


% Patents Active = 89.1

 

Average Co-Inventor Count = 3.0

ph-index = 18

Forward Citations = 1,048(Granted Patents)

Forward Citations (Not Self Cited) = 1,028(Dec 10, 2025)


Inventors with similar research interests:


Location History:

  • Ibaraki, JA (1977)
  • Hitachi, JA (1976 - 1978)
  • Hitachi, JP (1978 - 1982)
  • Ibaraki, JP (1982 - 1994)
  • Toukai, JP (1985 - 1995)
  • Naka-gun, Ibaraki JP (1995)
  • Tokyo, JP (2003)
  • Naka, JP (1990 - 2004)
  • Tokaimura, JP (1981 - 2009)
  • Tokai, JP (1982 - 2011)

Company Filing History:


Years Active: 1976-2011

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Areas of Expertise:
Induction Motor
PWM Inverter
Electric Power Converter
Motor Control
DC Apparatus
Electric Vehicle
Speed Control
Power Steering
Vector Control
Converter Control
Machine Tool
Multi-Inverter System
55 patents (USPTO):Explore Patents

Title: Toshiaki Okuyama: Driving Innovations in Electric Power Conversion and Induction Motor Control

Introduction:

Toshiaki Okuyama is a highly accomplished inventor and engineer based in Tokai, Japan. With an impressive total of 51 patents to his name, Okuyama is widely recognized for his groundbreaking contributions in the field of electric power conversion and induction motor control. This article will explore Okuyama's latest patents, his notable affiliations with renowned companies, and highlight some of his esteemed colleagues in the industry.

Electric Power Converter Suppressing Output Voltage Variation due to Input Voltage Fluctuation:

One of Okuyama's recent patents involves an electric power converter apparatus designed to regulate output voltage stability in the face of fluctuating input voltages. This innovative technology allows the converter to decrease and increase the output voltage based on predetermined thresholds, ensuring a constant output voltage even during power source variations. Okuyama's research in this area provides enhanced reliability and efficiency for various electrical systems.

Induction Motor Controller:

Within the realm of induction motor control, Okuyama's patent for an induction motor controller showcases his expertise. This technology incorporates a circuit for generating a d-axis current reference signal, a d-axis current controller, and parameter determining means to calculate and determine the motor parameter of the induction motor. By accurately controlling the voltage applied to the motor, Okuyama's invention enables efficient performance and optimized operation of induction motors.

Professional Experience and Affiliations:

Okuyama has been involved with renowned companies at the forefront of technological advancements. He has worked at Hitachi Co., Ltd and Hitachi Industrial Equipment Systems Co., Ltd. These companies, known for their commitment to innovation, have provided an ideal platform for Okuyama to develop and implement his groundbreaking inventions and improvements.

Noteworthy Colleagues:

Throughout his career, Okuyama has collaboratively worked with accomplished individuals in the field. Two notable colleagues include Yuzuru Kubota and Hiroshi Nagase. The collective expertise and collaborative efforts of these inventors further contributed to the realization and implementation of ground-breaking technologies that shaped the industry.

Conclusion:

Toshiaki Okuyama's accomplishments in the spheres of electric power conversion and induction motor control reflect his profound knowledge and dedication to driving innovation. With a remarkable portfolio of 51 patents, his inventions and technologies have significantly contributed to the advancement of electrical systems. His affiliations with renowned companies like Hitachi Co., Ltd and Hitachi Industrial Equipment Systems Co., Ltd have augmented his ability to turn ideas into practical realities. As the world embraces sustainable energy and advanced motor control, Okuyama's contributions will continue to shape the future of the industry.

Profile summary based on public USPTO records.
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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