Location History:
- Atsugi, JP (2004)
- Kanagawa, JP (1998 - 2011)
Company Filing History:
6 out of 58,131 
1 out of 832,880 Years Active: 1998-2011
Title: Keiji Narusawa: Innovator in Photodetection and Reproducing Amplifier Technologies
Introduction
Keiji Narusawa is a prominent inventor based in Kanagawa, Japan. He has made significant contributions to the fields of photodetection devices and reproducing amplifiers. With a total of 7 patents to his name, Narusawa's work has had a lasting impact on technology.
Latest Patents
Narusawa's latest patents include a photodetection device and an optical disk device. The photodetection device features a photoelectric converter that transforms light into electric current. It also includes an electrical current/voltage converter with a feedback circuit that adjusts the output voltage based on the resistance value of the feedback circuit. This innovative design incorporates a first MOS transistor that allows for variable resistance in accordance with the gate voltage.
Another notable patent is for a reproducing amplifier and a magnetic recording and reproducing apparatus. This invention addresses the issue of prolonged transition times from write mode to read mode, particularly when cross talk occurs between the recording head and the reproducing amplifier. The reproducing amplifier is equipped with a differential pair of transistors and a switching circuit that supplies bias voltage to each transistor's base. This circuit operates during the write mode and for a fixed period after transitioning to read mode, effectively reducing the input impedance during these times.
Career Highlights
Throughout his career, Narusawa has worked with notable companies, including Sony Corporation. His experience in these organizations has allowed him to refine his skills and contribute to groundbreaking technologies.
Collaborations
Narusawa has collaborated with esteemed colleagues such as Michiya Sako and Norio Shoji. These partnerships have fostered innovation and have been instrumental in the development of his patented technologies.
Conclusion
Keiji Narusawa's contributions to photodetection and reproducing amplifier technologies highlight his role as a significant inventor in the field. His innovative patents continue to influence advancements in technology.