Light down conversion film and display backlight unit using the same

摘要

The disclosure provides a display backlight unit and its light down conversion film. The light down conversion film may include a quantum-dot layer sandwiched between input substrate and an exit substrate. First and second refractive asymmetric micro-prisms are disposed on two opposite input and first exit surfaces of the input substrate, respectively. On the input surface of the input substrate, multiple arrays of the asymmetric refractive asymmetric micro-prisms preserve the large off-axis angle of incident light with first wavelength. On the first exit surface of the input substrate, multiple arrays of the refractive asymmetric micro-prisms increase the reflectance of the large incident angle light. A second exit surface of the exit substrate includes refractive symmetric micro-prisms. The refractive asymmetric micro-prisms of the input substrate and the refractive asymmetric micro-prisms of the exit substrate have rounded tips and valleys for enhancing refraction of the first light and the second light.

主权项

1. A display backlight unit, comprising:
at least one light source comprising a light emission window and adapted to emit first light with first wavelength through the light emission window; a light guide plate located adjacent to the light emission window of the at least one light source, the light guide plate including an input edge and a light-guide exit surface and adapted to receive the first light via the input edge and spread out the first light within the light guide plate, then extract the first light uniformly over the back light unit, the first light extracted exiting the light guide plate via the light-guide exit surface at a range of off-axis angles, and an illuminance of the first light extracted being allowed to have fluctuations across the back light unit; and a light down conversion film comprising at least one quantum-dot layer with more than one population of quantum dots and at least one input substrate, the input substrate disposed on the light-guide exit surface of the light guide plate, the quantum dots adapted to absorb a part of the first light with first wavelength which exits the light guide plate and the input substrate in sequence before down-converting into second light with second wavelength and reemitting, another part of the first light which is unabsorbed passing through the light down conversion film, and the first wavelength being shorter than the second wavelength; wherein the input substrate includes an input surface facing towards the light guide plate and a first exit surface facing towards the quantum-dot layer, the input surface comprises a plurality of first refractive asymmetric micro-prisms, wherein each of the first refractive asymmetric micro-prisms includes a first steep segment facing toward the input edge of the light guide plate and a first shallow segment connected to the first steep segment, the first exit surface of the input substrate is facing the quantum-dot layer, the first exit surface of the input substrate comprises a plurality of second refractive asymmetric micro-prisms and each includes a second steep segment facing away from the input edge of the light guide plate and a second shallow segment connected to the second steep segment, the first steep segments and the first shallow segments adjacent to each other form a first rounded tip and a first rounded valley for refraction of the first light and the second light, and the second steep segments and the second shallow segments adjacent to each other form a second rounded tip and a second rounded valley for refraction of the first light and the second light.