Location History:
- Kanagawa, JP (1990 - 1993)
- Chiba, JP (1997 - 2000)
Company Filing History:
Years Active: 1990-2000
Title: Etsufumi Yamamoto: Innovator in Optical Disc Technology
Introduction
Etsufumi Yamamoto is a prominent inventor based in Kanagawa, Japan. He has made significant contributions to the field of optical disc technology, holding a total of 8 patents. His work has been instrumental in advancing the efficiency and functionality of disc recording and reproduction systems.
Latest Patents
Yamamoto's latest patents include an innovative optical disc apparatus and a tracking error signal calculation circuit. The tracking error signal calculation circuit features peak detection multiplication circuits that identify the peaks of detection signals from the left and right regions of a photodiode. These circuits multiply a coefficient to detect the deviation of the beam light concerning the track of the disc recording medium. Additionally, subtraction circuits are employed to eliminate offsets by subtracting the multiplication results from the detection signals. The circuit also calculates the difference of the signal obtained after removing the offset, performing a push-pull operation to output a tracking error signal. Notably, the coefficient's value can be adjusted by adding an alignment signal to the detection signal, with frequency dependency imparted through a filter.
Another significant patent involves an apparatus and method for controlling the rotational speed during a pause in a disc drive. This innovation ensures that the rotational speed of the disc during a pause operation is lower than when information is being recorded or reproduced, enhancing the overall performance of disc recording/reproduction apparatuses.
Career Highlights
Etsufumi Yamamoto has dedicated his career to developing cutting-edge technologies at Sony Corporation. His expertise in optical disc technology has positioned him as a key figure in the industry, contributing to the advancement of disc-based media.
Collaborations
Yamamoto has collaborated with notable colleagues, including Hidehiro Kume and Yoshiyuki Matsumoto. Their combined efforts have led to significant advancements in optical disc technology.
Conclusion
Etsufumi Yamamoto's innovative work in optical disc technology has resulted in multiple patents that enhance the functionality of disc recording and reproduction systems. His contributions continue to influence the industry and pave the way for future advancements.