Patent ID: 7492083

Claim:
A green light-emitting alkaline earth aluminate phosphor for a cold cathode fluorescent lamp, which is represented by the compositional formula a(P 1-x Eu x )O.(Q 1-y Mn y )O.bAl 2 O 3 and which emits green light when irradiated with ultraviolet rays having a wavelength of from 180 to 300 nm, wherein P represents at least one alkaline earth metal element selected from the group consisting of Ba, Sr and Ca, Q represents at least one bivalent metal element selected from the group consisting of Mg and Zn, and a, b, x and y represent numbers which satisfy the following relationships; 0.8≦a≦1.2, 4.5≦b≦5.5, 0.05≦x≦0.25, 0.2≦y≦0.4, wherein said green light-emitting alkaline earth aluminate phosphor emits light having a first emission peak as a minor emission peak in a wavelength region of from 445 to 455 nm and having a second emission peak as a major emission peak in a wavelength region of from 510 to 520 nm, when irradiated with ultraviolet rays having a wavelength of from 180 to 300 nm, and wherein when the intensity of the above first emission peak and the intensity of the above second emission peak are represented as P 1 and P 2 , respectively, the intensity ratio (P 2 /P 1 ) is at least 14.5.