Akinobu Umemura

Title: Akinobu Umemura: Innovator in Capacitive Sensor Technology

Introduction

Akinobu Umemura is a prominent inventor based in Nagoya, Japan. He has made significant contributions to the field of sensor technology, particularly in capacitive sensors. With a total of 5 patents to his name, Umemura continues to push the boundaries of innovation in this area.

Latest Patents

One of his latest inventions is a capacitive physical quantity sensor. This sensor includes a sensor element and a detecting element, where the sensor element consists of first and second fixed electrodes facing a movable electrode. A first voltage is applied to the first fixed electrode, while a second voltage is applied to the second fixed electrode. The detecting circuit features a capacitance-voltage conversion circuit, which includes an operational amplifier, a capacitor, and a switch that comprises both a P-channel MOS transistor and an N-channel MOS transistor. The transistors are designed with a back gate potential that is approximately equal to the average voltage of the first and second voltages.

Another notable invention is a capacitive-type physical quantity sensor. In this design, a substrate forming the sensor element is connected to a non-inverting input terminal of an operational amplifier. A common voltage is applied from a reference voltage supply circuit to ensure that both are fixed to the same potential. This configuration allows for matching the impedances of the non-inverting and inverting input terminals of the operational amplifier concerning the power source. Consequently, noise superimposed on the power source line can be significantly reduced due to the noise-removing characteristics determined by the common-mode rejection ratio (CMRR) of the operational amplifier. This results in a capacitive-type acceleration sensor that exhibits enhanced sensor characteristics with a frequency noise suppressing effect.

Career Highlights

Akinobu Umemura is currently employed at Denso Corporation, a leading global automotive supplier. His work at Denso has allowed him to focus on developing advanced sensor technologies that are crucial for modern automotive applications.

Collaborations

Throughout his career, Umemura has collaborated with notable colleagues, including Junji Hayakawa and Norio Kitao. These collaborations have contributed to the advancement of sensor technology and have fostered innovation within the industry.

Conclusion

Akinobu Umemura is a distinguished inventor whose work in capacitive sensor technology has made