Backlight system for liquid crystal display comprising prism lens having apex angle of 80 DEG -85 DEG and refractive index of 1.57-1.59

摘要

A liquid crystal display comprises a liquid crystal display device (30), a backlight system (20) provided with a prism lens sheet (10). The lens sheet comprises a transparent base sheet (11), and a lens sheet formed integrally with the base sheet and provided with a plurality of parallel unit lenses (12). Each of the unit lenses (12) has a cross section of a shape of an isosceles triangle having an apex angle ( alpha ) in the range of 80 DEG to 87 DEG , and is made of a radiation setting resin having a refractive index in the range of 1.57 to 1.59. The prism lens sheet has a half-brightness viewing angle of 65 DEG or below, and the difference between the half-brightness viewing angle and a brightness-curve inversion angle is 20 DEG or above to prevent information displayed on the screen of the liquid crystal display from being seen sidewise by others.