Light reflecting film, and light controlling film, optical film, functional glass and head-up display including the light reflecting film

A light controlling film comprising a light reflecting film and a light controlling layer that are laminated,

• the light reflecting film including at least two light reflecting layers that are laminated, the at least two light reflecting layers including at least one of light reflecting layers among a light reflecting layer PRL-1, a light reflecting layer PRL-2 and a light reflecting layer PRL-3,
• the light reflecting layer PRL-1 having a central reflection wavelength of greater than or equal to 400 nm but less than 500 nm and a reflectance to ordinary light at the central reflection wavelength of greater than or equal to 5% but less than or equal to 25%,
• the light reflecting layer PRL-2 having a central reflection wavelength of greater than or equal to 500 nm but less than 600 nm and a reflectance to ordinary light at the central reflection wavelength of greater than or equal to 5% but less than or equal to 25%,
• the light reflecting layer PRL-3 having a central reflection wavelength of greater than or equal to 600 nm but less than 700 nm and a reflectance to ordinary light at the central reflection wavelength of greater than or equal to 5% but less than or equal to 25%,
• the at least two light reflecting layers having central reflection wavelengths that are different from each other,
• all of the at least two light reflecting layers that are laminated having a property of reflecting polarized light that has the same orientation,
• the light controlling layer comprising two quarter wave plates,
• the light reflecting film being laminated so as to be interposed between the two quarter wave plates,
• wherein each of the light reflecting layers has a half width of greater than or equal to 100 nm but less than or equal to 500 nm, and the half width is a full width at half maximum which is a width of wavelength defined by a difference between a wavelength at a long wavelength side and a wavelength at a short wavelength side corresponding to 50% of a maximum reflectance of each of the light reflecting layers, and
• wherein a wavelength corresponding to 50% of the maximum reflectance is calculated based on a reflectance derived from selective reflectance obtained by subtracting an average value of a reflectance other than the selective reflection region from a value of the maximum reflectance in the selective reflection region.