SECURITY FILM FOR DISPLAY DEVICE AND METHOD OF MANUFACTURING THE SAME

摘要

The present invention discloses a security film for a display device, which comprises a birefringent layer formed of a material having a birefringence property and having a plurality of linear protrusion portions and a plurality of linear groove portions alternately arranged on an exit surface thereof, wherein the plurality of linear protrusion portions allow polarization of incident light to be changed and then the light to be transmitted and the plurality of linear groove portions allow polarization of incident light not to be changed or to be changed less than the linear protrusion portions and then the light to be transmitted; and a polarizing layer provided on the exit surface of the birefringent layer, wherein the polarizing layer allows the polarized light transmitted through any one of the protrusion and groove portions to be transmitted but the polarized light transmitted through the other of the protrusion and groove portions not to be transmitted. Here, a phase delay value A of the protrusion portion, a phase delay value B of the groove portion and maximum and minimum wavelengths ?max and ?min of light incident on the birefringent layer preferably have a relation as follows: A - B| > a x ?min - 100nm and | A - B| min + 100nm, where "a" is an integer. Width w and height h of the linear protrusion portion may have a relation of w/h=l, and the width w of the linear protrusion portion and width w' of the groove portion may have a relation of w/w' = 1.