Patent ID: 10139533

Abstract:
According to the invention, there is provided a circular polarizing filter for selectively transmitting circularly polarized light of any one sense of either right-handed circularly polarized light or left-handed circularly polarized light at a specific wavelength in which scattering transmittance/vertical transmittance when circularly polarized light of the sense of the specific wavelength enters from any one surface is less than scattering reflectance/regular reflectance when circularly polarized light of the other sense enters from the surface. The circular polarizing filter includes a circularly-polarized light separating layer, the circularly-polarized light separating layer includes a reflected light-scattering circularly-polarized light separating layer, and may further include a reflected light-non-scattering circularly-polarized light separating layer, the reflected light-scattering circularly-polarized light separating layer is composed of a layer having a cholesteric liquid crystalline phase fixed therein, and the reflected light-non-scattering circularly-polarized light separating layer is composed of a layer having a cholesteric liquid crystalline phase fixed therein, or a laminate including a linearly-polarized light separating layer and a λ/4 phase difference layer. The circular polarizing filter of the invention has a high circular polarizance, and a high-sensitivity sensor system can be provided using the circular polarizing filter of the invention.