| CPC G02B 6/0056 (2013.01) [G02B 6/0055 (2013.01); G02F 1/13362 (2013.01)] | 20 Claims |
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1. An optical system comprising:
an extended illumination source configured to emit light from an extended emission surface thereof toward a display panel, the emitted light comprising substantially distinct blue, green and red emission spectra comprising respective blue, green and red peaks at respective blue, green and red peak wavelengths and corresponding blue, green and red full widths at half maxima (FWHMs), the blue FWHM extending from a smaller blue wavelength to a longer blue wavelength;
a reflective polarizer disposed on the emission surface of the extended illumination source and comprising a plurality of first polymeric layers numbering at least 10 in total; and
an optical filter disposed between the reflective polarizer and the emission surface of the extended illumination source and comprising a plurality of second polymeric layers numbering at least 10 in total, each of the first and second polymeric layers having an average thickness of less than about 300 nm, such that for a substantially normally incident light:
for each of the blue, green and red peak wavelengths, the plurality of first polymeric layers reflects greater than about 60% of the incident light having a first polarization state and transmits greater than about 60% of the incident light having an orthogonal second polarization state;
for each of the green and red peak wavelengths and for each of the first and second polarization states, the plurality of second polymeric layers transmits greater than about 70% of the incident light; and
for the smaller blue wavelength and for each of the first and second polarization states, the plurality of second polymeric layers transmits less than about 60% of the incident light.
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