Company Filing History:
2 out of 1,027 
1 out of 3 Years Active: 2025
Title: Keisuke Kawai: Innovator in Optical Filter Technology
Introduction
Keisuke Kawai is a prominent inventor based in Tokyo, Japan. He has made significant contributions to the field of optical filter technology, holding two patents that showcase his innovative approach to enhancing optical performance.
Latest Patents
Kawai's latest patents focus on advanced optical filters. The first patent describes an optical filter that includes a substrate and a dielectric multilayer film. This film is laid on or above at least one major surface of the substrate and consists of at least two different layers. Notably, the dielectric multilayer film has a spin density of 5.0×10/nm·cm or larger. It also features a surface hardness of 5.5 GPa or higher when measured with a load of 1 mN. The filter achieves a maximum transmittance of 6% or lower at an incident angle of 0° within the wavelength range of 400 nm to 680 nm, and a maximum reflectance of 20% or lower at an incident angle of 5° in the same wavelength range. Additionally, it boasts an average transmittance of 90% or higher in at least one wavelength range of 50 nm width.
The second patent also pertains to an optical filter, which includes a substrate and a dielectric multilayer film with four or more films. Each of these films has a spin density of 5.0×10/nm·cm or larger and a minimum thickness ranging from 1.5 nm to 5 nm. Similar to the first patent, it maintains a maximum transmittance of 6% or lower at an incident angle of 0° in the wavelength range of 400 nm to 680 nm, and a maximum reflectance of 20% or lower at an incident angle of 5°. Furthermore, it achieves an average transmittance of 90% or higher in at least one wavelength range of 40 nm within the 800 nm to 1570 nm spectrum.
Career Highlights
Throughout his career, Kawai has worked with notable companies such as AGC Inc. and Optical Coatings Japan. His experience in these organizations has allowed him to refine his skills and contribute to cutting-edge optical technologies.
Collaborations
Kawai has collaborated with esteemed colleagues, including Hideaki Takahoshi and Kazuya