Light-emitting apparatus and illuminating apparatus

• US 20050236628A1
• Filed: 02/25/2005
• Published: 10/27/2005
• Est. Priority Date: 02/26/2004
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Matsuura, Shingo
• Granted Patent: US 7,192,164 B2
• Time in Patent Office: Days
• US Class Current: 257/79
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• 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
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A light-emitting apparatus includes a light-emitting element, a base body, a reflection member and a fluorescent material layer. A cross section of the inner surface of the reflection member cut by a virtual plane including a virtual axis penetrating a center of the inner surface and perpendicular to the upper principal surface of the base body has a sectional profile defined by a curved line expressed by the following formula, and the inner surface of the reflection member is a curved surface obtained by rotating the curved line about the virtual axis: Z=(cr²)/[1+{1−(1+k)c²r²}^1/2] (where −10≦k≦−0.001, 0.001≦c≦10). An angle θ₁ which is made by an upper surface of the fluorescent material layer and a line which connects one corner of a light-emitting portion of the light emitting element with an uppermost position of the inner surface and is tangent to the one corner, is given as θ₁≧90°−sin⁻¹ (1/n₁)

Claims

1. A light-emitting apparatus comprising:

a light-emitting element;

a base body having a convexity formed on an upper principal surface thereof for emplacing the light-emitting element thereon;

a reflection member disposed on the upper principal surface of the base body so as to surround the convexity, having an inner surface which is formed as a reflection surface for reflecting light emitted from the light-emitting element emplaced on the convexity; and

a fluorescent material layer disposed on a top surface of the reflection member so as to cover the light-emitting element, with a spacing secured between the fluorescent material layer and the light-emitting element, the fluorescent material layer being composed of a light transmitting member that contains a fluorescent material for performing wavelength conversion on the light emitted from the light-emitting element,

wherein a cross section of the inner surface of the reflection member cut by a virtual plane including a virtual axis penetrating a center of the inner surface and perpendicular to the upper principal surface of the base body has a sectional profile defined by a curved line expressed by the following formula, and the inner surface of the reflection member is a curved surface obtained by rotating the curved line about the virtual axis;

Z=(cr²)/[1+{1−

(1+k)c²r²}^1/2] (where −

10≦

k≦

−

0.001, 0.001≦

c≦

10)

where r represents a radius from the virtual axis to the inner surface;

Z represents a height from a lowermost position of the inner surface to a position having a radius r of the inner surface,

and wherein an angle θ

₁ which is made by an upper surface of the fluorescent material layer and a line which connects one corner of a light-emitting portion of the light emitting element with an uppermost position of the inner surface and is tangent to the one corner, is given as;

θ

₁≧

90°

−

sin<sup>−

1</sup> (1/n₁)

where n₁ represents a refractive index of the fluorescent material layer.

2. The light-emitting apparatus of claim 1, wherein an arithmetic average roughness Ra of the inner surface is in a range of 0.004 to 4 μ

m.

3. The light-emitting apparatus of claim 1, wherein a spacing bounded by the inner surface of the reflection member and a lower surface of the fluorescent material layer is filled with a light transmitting member composed of a same material as that of the light transmitting member constituting the fluorescent material layer.

7. An illuminating apparatus constructed by setting up a plurality of the light-emitting apparatuses of claim 1 in a predetermined arrangement.

8. The illuminating apparatus of claim 7, wherein the predetermined arrangement is a staggered arrangement.

9. The illuminating apparatus of claim 7, wherein the predetermined arrangement is a concentric arrangement of groups of light-emitting apparatuses which groups of light-emitting apparatuses are circularly or polygonally arranged, and numbers of light-emitting apparatuses of the respective groups become larger gradually from a center to an outer edge of the illuminating apparatus.

4. A light-emitting apparatus comprising:

a light-emitting element;

a platy base body;

a reflection member joined to an upper principal surface of the base body, the reflection member having a base portion, a convexity formed on the base portion, for emplacing thereon the light-emitting element, and a side wall portion formed on a periphery of the base portion so as to surround the convexity, the side wall portion having an inner surface which is formed as a reflection surface for reflecting light emitted from the light-emitting element emplaced on the convexity; and

a fluorescent material layer disposed on a top surface of the side wall portion so as to cover the light-emitting element, with a spacing secured between the fluorescent material layer and the light-emitting element, the fluorescent material layer being composed of a light transmitting member that contains a fluorescent material for performing wavelength conversion on the light emitted from the light-emitting element,

wherein a cross section of the side wall portion cut by a virtual plane including a virtual axis penetrating a center of the inner surface and perpendicular to the upper principal surface of the base body has a sectional profile defined by a curved line expressed by the following formula, and the inner surface of the reflection member is a curved surface obtained by rotating the curved line about the virtual axis;

Z=(cr²)/[1+{1−

(1+k)c²r²}^1/2] (where −

10≦

k≦

−

0.001, 0.001≦

c≦

10)

where r represents a radius from the virtual axis to the inner surface;

Z represents a height from a lowermost position of the inner surface to a position having a radius r of the inner surface,

and wherein an angle 01 which is made by an upper surface of the fluorescent material layer and a line which connects one corner of a light-emitting portion of the light emitting element with an uppermost position of the inner surface and is tangent to the one corner, is given as;

θ

₁≧

90°

−

sin<sup>−

1</sup> (1/n₁)

where n₁ represents a refractive index of the fluorescent material layer.

5. The light-emitting apparatus of claim 4, wherein an arithmetic average roughness Ra of the inner surface is in a range of 0.004 to 4 μ

m.

6. The light-emitting apparatus of claim 4, wherein a spacing bounded by the inner surface of the reflection member and a lower surface of the fluorescent material layer is filled with a light transmitting member composed of a same material as that of the light transmitting member constituting the fluorescent material layer.

10. An illuminating apparatus constructed by setting up a plurality of the light-emitting apparatuses of claim 4 in a predetermined arrangement.

11. The illuminating apparatus of claim 10, wherein the predetermined arrangement is a staggered arrangement.

12. The illuminating apparatus of claim 10, wherein the predetermined arrangement is a concentric arrangement of groups of light-emitting apparatuses which groups of light-emitting apparatuses are circularly or polygonally arranged, and numbers of light-emitting apparatuses of the respective groups become larger gradually from a center to an outer edge of the illuminating apparatus.