Company Filing History:
12 out of 42,485 
3 out of 18 
1 out of 162 Years Active: 1992-2013
Title: Innovative Mind: The Contributions of Inventor Hidefumi Shirahama
Introduction: Hidefumi Shirahama is a notable inventor based in Hitachi, Japan, renowned for his significant contributions to the field of synchronous motor technology. With a remarkable portfolio of 12 patents, his innovations have had a lasting impact on the industry.
Latest Patents: Among his latest patents are groundbreaking inventions such as a synchronous motor and control method for synchronous motors. This invention incorporates a three-phase inverter and position sensors, along with a unit designed to calculate digital input current values from the analog outputs of input current detection circuits. Additionally, the motor features a digital feedback speed control unit that adjusts the amplitudes and frequency of AC voltages from the three-phase inverter, allowing the motor speed to closely match a commanded speed value received externally. Shirahama’s synchronous motor also encompasses a communication transmission unit that relays input current values and motor speeds outside the system.
Another significant patent is the apparatus and method for driving synchronous motors. This invention involves position sensors, a current polarity detection circuit that identifies the polarities within the phase windings, and an inverter that drives the motor. The motor speed calculation unit derives the rotational speed based on signals from the position sensors, while a speed control unit ensures that the motor speed aligns with desired command values. Furthermore, a phase control unit adjusts the phase differences between sensor signals and phase winding currents to maintain a predetermined value.
Career Highlights: Hidefumi Shirahama has made substantial contributions during his career at renowned companies such as Hitachi, Ltd. and Hitachi Information & Control Solutions, Ltd. His work has been pivotal in enhancing the performance and efficiency of electrical machinery, particularly in the field of synchronous motors.
Collaborations: Throughout his career, he has collaborated with notable individuals, including Tsunehiro Endo and Norikazu Tokunaga. Their collective efforts in advancing motor technology have helped position their work at the forefront of innovation.
Conclusion: In summary, Hidefumi Shirahama’s inventive spirit and technical expertise are evident in his patents and career contributions. His advancements in synchronous motor technology not only demonstrate his commitment to innovation but also his significant role in shaping the future of electrical machinery.
Inventor’s Patent Attorneys refers to legal professionals with specialized expertise in representing inventors throughout the patent process. These attorneys assist inventors in navigating the complexities of patent law, including filing patent applications, conducting patent searches, and protecting intellectual property rights. They play a crucial role in helping inventors secure patents for their innovative creations.