Patent ID: 11647169

Abstract:
Provided is a reflective screen and a projection image display system in which a transmittance of light can be selectively changed, a transmittance in a transparent state is sufficiently high, a voltage does not need to be applied constantly, and a voltage is applied to decrease a transmittance of light in a case where the reflective screen is irradiated with video light. The reflective screen includes: a light reflecting layer that is formed of a cholesteric liquid crystal layer and where a selective reflection wavelength at a polar angle of 60° is present in a visible range, in which senses of helix of all of cholesteric liquid crystal layers are the same and Expression (1) is satisfied; and a transparent first electrode, a transparent second electrode, and a light control layer that are provided on a rear side with respect to the light reflective layer, the light control layer being disposed between the first electrode and the second electrode, in which the light control layer includes a polymer network and liquid crystal molecules and changes between a first state where light is scattered and a second state where transmission of light is allowed by changing a magnitude of a voltage applied, the polymer network having a three-dimensional net shape having a plurality of domains, and the liquid crystal molecules being positioned in the domains. R[−60,40](550)/R[−60,30](550)≥1.5  Expression (1)