Phosphor for Display and Field Emission Display

• US 20090039759A1
• Filed: 03/09/2007
• Published: 02/12/2009
• Est. Priority Date: 03/10/2006
• Status: Abandoned Application

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yamaguchi, Kenichi, Yokosawa, Nobuyuki
• Application Number:
  US12/280,945
• Publication Number:
  US 20090039759A1
• Time in Patent Office: Days
• US Class Current: 313/495
• CPC Class Codes: C09K 11/7731 with alkaline earth metals
• CPC Class Codes: H01J 29/20 characterised by the luminescent material
• CPC Class Codes: H01J 31/123 Flat display tubes

Abstract

Disclosed is a phosphor for displays which is characterized by being composed of a europium-activated thiogallate phosphor represented by the following chemical formula: SrGa₂S₄:Eu. This phosphor is also characterized by containing no gallium sulfide (Ga₂S₃) and being a green phosphor which emits light when excited by an electron beam having an accelerating voltage of 5-15 kV. Consequently, this invention provides a phosphor for displays having high luminance, which emits light when excited by a pulse electron beam having an accelerating voltage of 5-15 kV.

Claims

1. A phosphor for a display, comprising a europium (Eu)-activated thiogallate phosphor substantially represented by a chemical formula, SrGa₂S₄:

Eu free of gallium sulfide represented by a chemical formula, Ga₂S₃, wherein the phosphor is a green phosphor that emits light when excited by an electron beam having an accelerating voltage of 5 to 15 kV.

2. The phosphor for the display according to claim 1, wherein an XRD (X-ray diffraction) pattern of the europium-activated thiogallate phosphor has no peak indicative of gallium sulfide (Ga₂S₃) in a diffraction angle (2θ

) range of 27°

to 29°

.

3. A field emission display comprising phosphor layers including blue light emitting phosphor layers, green light emitting phosphor layers, and red light emitting phosphor layers;

an electron source configured to irradiate the phosphor layers with an electron beam having an accelerating voltage of 5 to 15 kV; and

an envelope configured to vacuum seal the electron source and the phosphor layers,

wherein the green light emitting phosphor layers include the phosphor for the display according to claim 1 or 2.