Patent ID: 9158042
Filing Date: 2015-10-13
Classification: F24S,G02B,H01L,Y02E,Y02P

Abstract:
1. A design method for a resin optical sheet comprising a base material comprising an ultraviolet absorber, the method comprising determining an amount of the ultraviolet absorber required to be present in the base material such that: in an accelerated degradation test using a metal-halide-lamp weathering test (device specification: JTM G 01:2000, Japan Testing Machinery Association), a decrease in an average transmittance in a wavelength range of 400 nm to 1850 nm after testing for an irradiation time T and such that a decrease in transmittance at each wavelength in the wavelength range, from a corresponding initial transmittance value to a transmittance value after the accelerated degradation test for the irradiation time T U W α U W α τuv(0): an average transmittance of the optical sheet in the wavelength range of 400 nm to 1850 nm before the accelerated degradation test, τuv(T τ τ wherein the amount of the ultraviolet light absorber is determined according to formula (1).