Light-emitting diode

• US 20030002272A1
• Filed: 06/26/2002
• Published: 01/02/2003
• Est. Priority Date: 06/28/2001
• Status: Active Grant

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Nakano, Hideyuki, Suehiro, Yoshinobu
• Granted Patent: US 6,900,587 B2
• Time in Patent Office: Days
• US Class Current: 362/84
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/32257 the layer connector connecting to a bonding area disposed in a recess of the surface of the item
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48257 connecting the wire to a die pad of the item
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 33/505 characterised by the shape, e.g. plate or foil
• CPC Class Codes: H01L 33/507 the elements being in intimate contact with parts other than the semiconductor body or integrated with parts other than the semiconductor body

Abstract

In an LED, when electric power is supplied to a blue light-emitting element through a pair of leads, light is emitted upward from an upper surface of the blue light-emitting element and, at the same time, light is radiated from side and lower surfaces of the blue light-emitting element so that a fluorescent substance is irradiated with the light. The latter light is reflected by a front surface of the fluorescent substance or by a concave reflecting mirror serving as a highly reflective material, so that the reflected light is radiated upward as excitation light (fluorescence) or as irradiation light. Because a radiating surface of a convex lens is formed above the concave reflecting mirror, the excitation light and irradiation light emitted thus are condensed by the convex lens and radiated externally with high external radiation efficiency.

Claims

1. A light-emitting diode comprising:

a light-emitting element; and

a fluorescent face made of a fluorescent substance containing at least one of inorganic and organic fluorescent materials and applied on a highly reflective material;

wherein a light is extracted externally from a side of said fluorescent face irradiated with light emitted from said light-emitting element.

2. A light-emitting diode according to claim 1, wherein said fluorescent face formed on said highly reflective material is disposed to surround side surfaces of said light-emitting element.

3. A light-emitting diode according to claim 1, wherein said fluorescent face formed on said highly reflective material is provided opposite to said light-emitting element.

4. A light-emitting diode according to claim 3, wherein said fluorescent face is formed in a paraboloid of revolution.

5. A light-emitting diode according to claim 1, wherein said light-emitting element emits ultraviolet light for performing irradiation;

and

said fluorescent substance contains at least one of inorganic and organic fluorescent materials, and is formed by applying said at least one fluorescent material on said highly reflective material so that the fluorescent material emits light when irradiated with said ultraviolet light.

7. A light-emitting diode according to claim 1, wherein a radiating surface is shaped in a convex cone.

6. A light-emitting diode comprising:

a light-emitting element;

a reflecting substrate on which said light-emitting element is disposed;

a cylindrical reflecting frame which is disposed on said reflecting substrate so as to surround said light-emitting element in a hollow portion of said reflecting frame;

a fluorescent face made of a fluorescent substance containing a fluorescent material applied so as to surround said light-emitting element on an area defined by an inner circumferential surface of said reflecting frame and a surface of said reflecting substrate which is exposed from said reflecting frame.

8. A light emitting diode comprising:

a light-emitting element;

a reflecting substrate opposed to said light-emitting element and having a surface shaped like a paraboloid of revolution focused on the light-emitting element;

wherein a fluorescent substance containing a fluorescent material is applied on the reflecting substrate to thereby form a fluorescent face.

9. A light-emitting diode according to claim 8, further comprising a metal plate of aluminum shaped like a paraboloid of revolution focused on the light-emitting element;

wherein the fluorescent substance is applied on an upper surface of the metal plate to thereby form a fluorescent face.

10. A light-emitting diode according to claim 8, wherein a silver thin film is formed on a back side of the fluorescent substance by vapor deposition.