Patent ID: 8780338

Claim:
An optical measuring device comprising: a light applying section configured to apply exciting light to a sample flowing in a channel; and a scattered light detecting section configured to detect scattered light generated from said sample irradiated with said exciting light on the downstream side of said sample in the traveling direction of said exciting light; and said scattered light detecting section including: a scattered light separating mask including a transmitting area and a reflecting area, said transmitting and reflecting areas arranged to separate said scattered light into a low numerical aperture component having a numerical aperture not greater than a specific value and a high numerical aperture component having a numerical aperture greater than said specific value; a first detector for detecting said low numerical aperture component; and a second detector for detecting said high numerical aperture component, wherein the numerical aperture of said high numerical aperture component is not smaller than 0.6, and wherein said scattered light separating mask transmits said low numerical aperture component having a numerical aperture not greater than 0.3 through the transmitting area, reflects said high numerical aperture component having a numerical aperture not smaller than 0.6in the reflecting area, and absorbs the other component having a numerical aperture greater than 0.3 and less than 0.6 in an absorbing area.