| abstract |
(57) [Summary] [Object] To provide a spherical rare earth oxysulfide phosphor capable of forming a dense and uniform phosphor screen. [Structure] Ln 2 O 2 S: R (where Ln is Y, L at least 1 selected from the group consisting of a, Gd, and Lu Element, R is at least one element selected from the lanthanide group) and has an average particle size of 0.5 to 1 5 μm, and the ratio of major axis to minor axis is 1.0 to 1.5 And a phosphor containing 0.5% by weight or less of ultrafine particles having a particle diameter of 0.2 μm or less. |