IP Library Granted Patent US 7,138,756
Granted Patent B2
US 7,138,756 · App. 10/949,312 · Granted Nov 21, 2006

Phosphor for electron beam excitation and color display device using the same

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Quick Facts
Patent No.
US 7,138,756
App. No.
10/949,312
Granted
Nov 21, 2006
Kind
B2
Abstract

A phosphor, which has less reduction in emission efficiency and is capable of keeping high luminance even when density of an electron beam for exciting the phosphor increases, is provided. As raw materials, Ca 3 N 2 (2N), AlN (3N), Si 3 N 4 (3N), and Eu 2 O 3 (3N) are prepared, and each of the raw materials is weighed so that a mole ratio of each element is, for example, (Ca+Eu):Al:Si=1:1:1, and mixed, then the mixture is held and fired at 1500° C. under the inert atmosphere for three hours, and thereafter ground to produce a phosphor having a composition formula of Ca 0.985 SiAlN 3 :Eu 0.015

Claims (11)

1. A phosphor for electron beam excitation expressed by a composition formula of MmAaBbOoNn:Z (where an element M is one or more bivalent elements, an element A is one or more trivalent elements, an element B is one or more tetravalent elements, O is oxygen, N is nitrogen, an element Z is an activator, and where values of m=a=b=1, o≧0, and n=2/3m+a+4/3b−2/3o).

2. The phosphor for electron beam excitation according to claim 1 , wherein the element M is one or more elements selected from Mg (magnesium), Ca (calcium), Sr (strontium), Ba (barium) and Zn (zinc), the element A is one or more elements selected from B (boron), Al (aluminum) and Ga (gallium), the element B is Si (silicon) and/or Ge (germanium), and the element Z is one or more elements selected from rare earth or transition metals.

3. The phosphor for electron beam excitation according to claim 1 , wherein the element A is Al (aluminum), and the element B is Si (silicon).

4. The phosphor for electron beam excitation according to claim 1 , wherein the element M is Ca (calcium) and the element Z is Eu (europium).

5. The phosphor for electron beam excitation according to claim 1 , wherein said phosphor for electron beam excitation is expressed by a general formula of CaAlSiN 3 :Eu.

6. The phosphor according to claim 1 , wherein said phosphor for electron beam excitation is in a powder form.

7. The phosphor for electron beam excitation according to claim 6 , wherein an average particle size of said phosphor for electron beam excitation is from 1 μm to 10 μm inclusive.

8. A color display device, wherein the phosphor for electron beam excitation according to claim 1 is used.

9. A method of exciting a phosphor to emit light by electron beam irradiation, comprising:

providing a phosphor expressed by a composition formula of MmAaBbOoNn:Z, where an element M is one or more bivalent elements, an element A is one or more trivalent elements, an element B is one or more tetravalent elements, O is oxygen, N is nitrogen, and an element Z is an activator, and where values of m>0, a>0, b>0, o≧0, where values of m=a=b=1, and n=2/3m+a+4/3b−2/3o); and

irradiating the phosphor with an electron beam.

Assignments (5)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 20, 2015
From: DOWA ELECTRONICS MATERIALS CO., LTD.
To: NICHIA CORPORATION; CITIZEN ELECTRONICS CO., LTD.
Reel/Frame 036382/0512 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Mar 9, 2012
From: DOWA HOLDINGS CO., LTD.
To: DOWA ELECTRONICS MATERIALS CO., LTD.
Reel/Frame 027833/0776 →
CHANGE OF NAME Recorded Jan 31, 2012
From: DOWA MINING CO., LTD.
To: DOWA HOLDINGS CO., LTD.
Reel/Frame 027626/0429 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 29, 2008
From: DOWA ELECTRONICS MATERIALS CO., LTD.
To: NICHIA CORPORATION
Reel/Frame 021311/0163 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jan 7, 2005
From: GOTOH, MASAHIRO; NAGATOMI, AKIRA; SAKANE, KENJI; YAMASHITA, SHUJI
To: DOWA MINING CO., LTD.
Reel/Frame 015567/0067 →