Phosphor, manufacturing method therefor, and cathode-ray tube using the same
AssigneeHitachi, Ltd.
InventorsHidetsugu Matsukiyo, Masatoshi Shiiki
Life of this patent
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Abstract
To provide a stable phosphor with a high brightness and little luminous degradation, a phosphor comprises yttrium, aluminum (a part or the whole of aluminum may be replaced with gallium), and oxygen as basic constituting elements, Tb or Ce as an activator, and the garnet structure as a crystal structure and in the curve 1-1 showing the temperature dependency of the thermoluminescence intensity, the integrated intensity of the thermoluminescence peak in the temperature range from 300K to 700K is made smaller than the integrated intensity of the thermoluminescence peak in the temperature range of less than 300K.
Claims33
A phosphor comprising yttrium, at least one selected from the group consisting of aluminum and gallium, and oxygen as basic constituting elements, Tb or Ce as an activator, and the garnet structure as a crystal structure, wherein in a curve showing the temperature dependency of the thermoluminescence intensity, the integrated intensity of the thermoluminescence peak in the temperature range from 300K to 700K is at most 1/100 of the integrated intensity of the thermoluminescence peak in the temperature range of less than 300K.
A phosphor expressed by a general formula (Y.sub.1-x O.sub.x).sub.3 (Al.sub.1-y Ga.sub.y).sub.5 O.sub.12 (x is a value within a range of 0.01.ltoreq.x.ltoreq.0.15 and y is a value within a range of 0.ltoreq.y.ltoreq.1), O is Tb or Ce, wherein in a curve showing the temperature dependency of the thermoluminescence intensity, the integrated intensity of the thermoluminescence peak in the temperature range from 300K to 700K is at most 1/100 or the integrated intensity of the thermoluminescence peak in the temperature range of less than 300K.
A method for manufacturing a phosphor having Y, Al, and Ga and containing Tb or Ce as an activator, comprising a step of heating in an oxidizing atmosphere at a temperature within a range of 1400.degree.-1600.degree. C. for 1-3 hours to incorporate Ga as Ga.sup.3+, and a step of heating in air at a temperature within a range of 1000.degree. to 1600.degree. C. for 1-3 hours to incorporate Tb or Ce as Tb.sup.3+ or Ce.sup.3+.
A method for manufacturing a phosphor having Y, at least one selected from the group consisting of Al and Ga, and Tb or Ce as activator, comprising the steps of oxidizing raw materials for forming the phosphor having Y, at least one selected from the group consisting of Al and Ga, and Tb or Ce as activator, together with a flux, at a temperature in a range from 1400.degree. to 1600.degree. C.;
- removing the flux, so as to obtain a product;
- and oxidizing the obtained product so as to reduce a defect level in the phosphor.
A method for manufacturing a phosphor having y and at least one selected from the group consisting of Al and Ga, comprising the step of oxidizing raw materials of said phosphor having Y and at least one of Al and Ga, together with a flux, at a temperature in a range of 1400.degree. to 1600.degree. C.;
- adding a material selected from the group consisting of Tb and Ce and acting as an emission center in the phosphor;
- and heat-treating so as to remove the flux.
A method for manufacturing a phosphor having at least Y and Ga, and containing Tb or Ce as an activator, comprising a step of heating in an oxidizing atmosphere at a temperature within a range of 1400.degree.-1600.degree. C. to incorporate Ga as Ga.sup.+3, and a step of heating in air at a temperature within a range of 1000.degree.-1600.degree. C. to incorporate Tb or Ce as Tb.sup.+3 or Ce.sup.+3.
Dependencies are inferred from the claim text.