Thin hollow backlights with beneficial design characteristics

摘要

A front and back reflector are arranged to form a hollow light recycling cavity having an output region, and one or more light sources (e.g. LEDs) are disposed to emit light into the cavity. In one aspect, the back reflector has a design characterized by a first and second parameter. The first design parameter is a ratio of the collective emitting area of the light sources Aemit to the area of the output region Aout, and Aemit/Aout is preferably from 0.0001 to 0.1. The second design parameter is SEP/H, where H is the depth of the recycling cavity, and SEP is an average plan view source separation associated with the light sources. Other aspects of the disclosed extended area light sources are also described.

主权项

1. An edge-lit backlight, comprising:
a front and back reflector forming a hollow light recycling cavity having a cavity depth H and an output region of area Aout; and one or more light sources disposed proximate a periphery of the backlight to emit light into the light recycling cavity, the light sources having an average plan view source separation of SEP and collectively having an active emitting area Aemit; wherein a first parameter equals Aemit/Aout; wherein a second parameter equals SEP/H; wherein the backlight is characterized by the first parameter being in a range from 0.0001 to 0.1, and by the second parameter being in a range from 3 to 10; and wherein the front reflector has a hemispherical reflectivity for unpolarized visible light of Rfhemi, and the back reflector has a hemispherical reflectivity for unpolarized visible light of Rbhemi, and (1−Rfhemi)/(1−Rbhemi) is at least 10.