Light emitting device and apparatus using the same

• US 7,161,567 B2
• Filed: 12/03/2003
• Issued: 01/09/2007
• Est. Priority Date: 12/05/2002
• Status: Expired due to Fees

• Current Assignee: Omron Corporation
• Original Assignee: Omron Corporation
• Inventors: Homma, Kenji, Kiyomoto, Hironobu, Ayabe, Takahiro
• Primary Examiner(s): Hjerpe; Richard
• Assistant Examiner(s): NGUYEN, KIMNHUNG T
• Application Number:
  US10/727,175
• Publication Number:
  US 20040119668A1
• Time in Patent Office: 1,133 Days
• Field of Search: 345 82- 84, 345/46, 359/247, 359/267, 359/318, 362/16, 362/555, 362/606
• US Class Current: 345/82
• CPC Class Codes: F21S 43/14 Light emitting diodes [LED]
• CPC Class Codes: F21W 2111/00 Use or application of lighting devices or systems for signalling, marking or indicating, not provided for in codes F21W2102/00 – F21W2107/00
• 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 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• 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 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/1815 Shape
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/60 Reflective elements

Abstract

A mold part formed of a light transmitting material having a high refractive index is molded in a concave-shaped reflecting member, and a light emitting element such as an LED chip or the like is inserted in the center of the mold part. A circular direct emitting portion is provided at the center of a front face of the mold part, a ring-shaped total reflecting portion is provided around it, and a slanted total reflecting portion is provided between the direct emitting portion and total reflecting portion. Thereby, the uniformity of front face luminance with a simple structure in a light emitting device provided with a reflecting member on a back face of a mold part is improved.

Claims

1. A light emitting device comprising a reflecting member for reflecting light, a light guiding member arranged at the side of a light reflecting surface of said reflecting member, and a light emitting element for emitting light toward said light guiding member, characterized in that the surface of the light emitting side of said light guiding member comprises a direct emitting portion for directly passing the light emitted from said light emitting element through to be emitted toward the outside of the light guiding member;

a first total reflecting portion for totally reflecting the light emitted from the light emitting element toward said reflecting member and passing the light reflected by the reflecting member through to be emitted toward the outside of the light guiding member; and

a second total reflecting portion configured so that the light emitted from the light emitting element is totally reflected toward the direct emitting portion, the light totally reflected by the direct emitting portion is directed to said reflecting member, and the light reflected by the reflecting member is emitted toward the outside of the light guiding member.

2. The light emitting device according to claim 1, characterized in that said second total reflecting portion is configured so that at least a part of the light reflected by said reflecting member after totally reflected by the second total reflecting portion and said direct emitting portion is emitted from a region in which neither the light passing through said direct emitting portion nor the light reflected by said first total reflecting portion and said reflecting member is emitted.

3. The light emitting device according to claim 1, characterized in that the surface of the light emitting side of said light guiding member comprises a third total reflecting portion in which the light emitted from said light emitting element is totally reflected toward said reflecting member, and the light reflected by the reflecting member is emitted to the outside of the light guiding member;

and the third total reflecting portion and the first total reflecting portion are positioned at different distances from said light emitting element.

4. The light emitting device according to claim 3, characterized in that said third total reflecting portion and said second total reflecting portion are arranged adjacently with each other.

5. The light emitting device according to claim 1, characterized in that said reflecting member comprises a region in which the light totally reflected by said first total reflecting portion is reflected, and a portion in which the light totally reflected by said second total reflecting portion and said direct emitting portion is reflected.

6. The light emitting device according to claim 3, characterized in that said reflecting member comprises a region in which the light totally reflected by said first total reflecting portion is reflected, a portion in which the light totally reflected by said second total reflecting portion and said direct emitting portion is reflected, and a portion in which the light totally reflected by third total reflecting portion is reflected.

7. The light emitting device according to claim 5, characterized in that said reflecting member further comprises a portion in which the light emitted from said light emitting element is reflected to be directly emitted from the surface of said light guiding member.

8. The light emitting device according to claim 1, characterized in that the whole of the surface of the light emitting side of said light guiding member is covered with a light transmitting medium having a refractive index different from that of the light guiding member.

9. The light emitting device according to claim 1, characterized in that a light transmitting portion in which light diffusing elements or phosphors are dispersed is formed between said light emitting element and said light guiding member.

10. A light emitting apparatus in which a plurality of the light emitting devices according to claim 1 are connected to each other, characterized in that the reflecting member is configured so that the light which was leaked from one of the adjacent light emitting devices to the light guiding member of a light emitting device is reflected by the reflecting member of the light emitting device and emitted from the surface of the light emitting device.

11. A luminaire comprising a light emitting apparatus in which a plurality of light emitting devices according to claim 1 are arranged, and a power supply unit supplying a power to said light emitting apparatus.

12. A display unit comprising a light emitting apparatus in which a plurality of light emitting devices according to claim 1 are arranged, and a controller controlling lighting of each light emitting device which constitutes said light emitting apparatus.

13. The light emitting device according to claim 6, characterized in that said reflecting member further comprises a portion in which the light emitted from said light emitting element is reflected to be directly emitted from the surface of said light guiding member.