Phosphor, light emitting apparatus, and liquid crystal display apparatus using the same

摘要

A phosphor as a divalent europium-activated oxynitride green light emitting phosphor which is a β-type SiAlON substantially represented by a general formula (A): EuaSibAlcOdNe (where a, b, c, d, and e are numbers satisfying 0.005≦a≦0.4, b+c=12, and d+e=16), and having an average particle size (d1) (determined by an air permeability method) of 9 to 16 μm, a median diameter (50% D) in particle size distribution of 12.5 to 35 μm, 50% D/d1 of 1.4 to 2.2, and an absorptance at 600 nm of not more than 8.0%, and a light emitting apparatus, a BL light source apparatus, and a liquid crystal display device using the same are provided, to provide a light emitting apparatus with a high efficiency and a stable characteristic and a liquid crystal display apparatus using the same by using the β-type SiAlON having controlled dispersibility and improved transparency.

主权项

1. A light emitting apparatus, comprising:
a light emitting element which is a gallium nitride-based semiconductor emitting primary light having a peak wavelength of 430 to 480 nm; and a light converter absorbing a part of said primary light to emit secondary light having a wavelength longer than a wavelength of the primary light, wherein the light emitting apparatus emits white light by color mixture of primary light and secondary light, said light converter including a green light emitting phosphor and a red light emitting phosphor, said green light emitting phosphor is a divalent europium-activated oxynitride green light emitting phosphor which is a β-type SiAlON substantially represented by a general formula (A): EuaSibAlcOdNe (where a, b, c, d, and e are numbers satisfying 0.005≦a≦0.4, b+c=12, and d+e=16), and 50% D/d1 of 1.4 to 2.2 (where 50% D is a median diameter in particle size distribution and d1 is an average particle size determined by an air permeability method), and an absorptance at 600 nm of not more than 8.0%, and said divalent europium-activated oxynitride green light emitting phosphor satisfies 9 μm≦d1≦16 μm, and 12.5 μm≦50% D≦35 μm.