Masanori Doi

Title: Masanori Doi: Innovator in Optical Disk Technology

Introduction

Masanori Doi is a prominent inventor based in Akishima, Japan. He has made significant contributions to the field of optical disk technology, holding a total of 8 patents. His work has advanced the functionality and efficiency of optical disk apparatuses, making him a notable figure in the industry.

Latest Patents

Masanori Doi's latest patents include a focus control apparatus for use with an optical disk. This invention discloses an optical disk apparatus where light returning from a recording medium is directed to a photodetector composed of multiple light-receiving elements. The focusing is controlled based on a focus error signal that corresponds to the relative distance between the objective and the recording medium. The apparatus determines whether the focusing pull has been conducted normally by comparing a standard added signal level, set by a focus search, to the level of an added signal generated after the focusing pull.

Another significant patent is the focus servo-circuit with ordered reference level setting means. This invention focuses light beams projected onto an optical recording medium by moving the focusing optical system vertically relative to the surface of the recording medium. A focus error signal, produced by receiving light returning from the recording medium, is compared with a predetermined plurality of reference levels. The focus servo means is activated when this signal reaches the reference level within the focus pull-in region after passing through a predetermined order of reference levels.

Career Highlights

Masanori Doi is currently employed at Olympus Optical Company, Ltd., where he continues to innovate in optical technologies. His work has been instrumental in enhancing the performance of optical disk systems, contributing to the company's reputation as a leader in imaging and optical products.

Collaborations

Masanori has collaborated with notable colleagues such as Saburo Funada and Yoshiro Yoda. Their combined expertise has fostered advancements in optical technology and has led to the successful development of several patents.

Conclusion

Masanori Doi's contributions to optical disk technology through his patents and collaborations highlight his importance as an inventor in the field. His work continues to influence advancements in optical systems, ensuring that he remains a key figure in the industry.