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US 8,283,848 B2Granted
Phosphor and image displaying device employing the same
AssigneeKabushiki Kaisha Toshiba
InventorNaotoshi Matsuda
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Abstract
The present invention provides a red-emitting phosphor emitting luminescence of excellent color purity with high efficiency under the excitation with near UV light, and it also provides a color image displaying device employing that phosphor. This phosphor comprises an ARS2 matrix (A is at least one of Na, K and Rb, and R is at least one of Y, Gd and Lu) doped with 0.003 to 0.3 mol % of Bi and 0.1 to 3 mol % of Mn, and is suitable as a red-emitting phosphor used in a color image displaying device without a color filter.
Claims7
A red-emitting phosphor, comprising:
- a matrix represented by the following formula (1):
- ARS2 (1)
- in which A is at least one element selected from the group consisting of Na, K and Rb;
- and R is at least one element selected from the group consisting of Y, Gd and Lu;
- and
- small amounts of Bi and Mn,
- wherein the content of Bi is 0.003 to 0.3 mol %, the content of Mn is 0.1 to 3 mol %, and the molar ratio of Bi/Mn is less than ⅓, and
- wherein the red-emitting phosphor emits red luminescence when exposed to light in the wavelength range of 380 to 430 nm.
5 more elements
An image displaying device comprising:
- an excitation light source giving off near UV light having a peak in the wavelength range of 380 to 430 nm,
- a phosphor layer comprising a phosphor emitting blue luminescence under the excitation with said near UV light,
- a phosphor layer comprising a phosphor emitting green luminescence under the excitation with said near UV light, and
- a phosphor layer comprising a phosphor emitting red luminescence under the excitation with said near UV light, and comprising:
- a matrix represented by the following formula (1):
- ARS2 (1)
- in which A is at least one element selected from the group consisting of Na, K and Rb;
- and R is at least one element selected from the group consisting of Y, Gd and Lu;
- and
- small amounts of Bi and Mn,
- wherein the content of Bi is 0.003 to 0.3 mol %, the content of Mn is 0.1 to 3 mol %, and the molar ratio of Bi/Mn is less than ⅓;
- wherein
- said phosphor layers are arranged in planar positions, according to each of which a liquid crystal element is provided so as to control transmittance of the excitation light or of the luminescence emitted from each corresponding phosphor.
10 more elements
Dependencies are inferred from the claim text.