OPTICAL FILM, BACKLIGHT, AND DISPLAY SYSTEM

Original (Chinese)

A backlight includes an illumination system and an optical film. The illumination system is configured to emit light from an emission surface thereof. The emitted light includes at least a red light including a red emission spectrum including a first red emission peak at a first red peak wavelength with a red full width at 70% maximum FWr1. The optical film disposed on red light emitting elements includes at least one spacer layer disposed between a plurality of first and second layers. For a substantially normally incident light and for a first polarization state, an optical transmittance of the optical film versus wavelength has a first red-infrared transmittance peak at a first red-infrared peak wavelength of greater than about 600 nm with a red-infrared full width at 70% maximum FWri1. The red-infrared peak wavelength is greater than the red peak wavelength by at least 10 nm, and FWri1/FWr1≥7.