White light source and display apparatus using the same

Abstract

A white light source includes an ultraviolet-visible excitation light generation unit capable of generating visible light and ultraviolet light, and a fluorescence generation unit having a phosphor layer and being capable of generating visible light upon excitation by the ultraviolet light and uses, in the phosphor layer, a red light emitting phosphor represented by the following compositional formula: (Ca1−a−bSraEub)S:Mc, wherein a, b and c satisfy the following conditions: 0≦a<1.0, 0≦b<0.1 and 0≦c≦0.1; and M is a dopant element having absorption of excitation energy at about 350 nm to about 500 nm. The dopant element M includes rare earth elements such as Ce, Yb, Gd and Tm. By substituting part of Ca and/or Sr with Zn, the white light source can exhibit further improved performances. The white light source exhibits an increased red light component as compared with light emitted from conventional (Y1−a−bGdaCeb)3(Al1−cGac)5O12 green light phosphors and is suitably used in display apparatus.

Dependencies are inferred from the claim text.