Light emitting device

• US 20080283860A1
• Filed: 06/02/2008
• Published: 11/20/2008
• Est. Priority Date: 06/15/2007
• Status: Abandoned Application

• Current Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Original Assignee: Toyoda Gosei Company Limited (Toyota Motor Corporation)
• Inventors: Tasumi, Koji, Suehiro, Yoshinobu
• Application Number:
  US12/155,326
• Publication Number:
  US 20080283860A1
• Time in Patent Office: Days
• US Class Current: 257/98
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer
• CPC Class Codes: G02B 6/0048 with stepwise taper
• CPC Class Codes: G02B 6/0071 with elongated shape, e.g. tube
• CPC Class Codes: G02B 6/0083 Details of electrical connections of light sources to drivers, circuit boards, or the like
• CPC Class Codes: G02B 6/0085 Means for removing heat created by the light source from the package heat extraction or cooling elements for semiconductor light sources in general H01L33/64
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 33/58 Optical field-shaping elements
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H01L 33/642 characterized by the shape

Abstract

A light emitting device includes an emission portion, an optical control portion for reflecting or refracting light emitted from the emission portion in a predetermined direction, a light guiding member including a light input surface to which the reflected or refracted light is inputted, a refection region formed on a surface thereof for reflecting the inputted light, and a light output surface for externally outputting the reflected light from the refection region, a reflection portion, on which the emission portion is mounted and which covers externally the refection region, for dissipating heat generated from the emission portion and for reflecting light passing through the refection region in a direction of the light output surface, and a space formed between the light guiding member and the reflection portion.

Claims

1. A light emitting device, comprising:

an emission portion;

an optical control portion for reflecting or refracting light emitted from the emission portion in a predetermined direction;

a light guiding member comprising a light input surface to which the reflected or refracted light is inputted, a refection region formed on a surface thereof for reflecting the inputted light, and a light output surface for externally outputting the reflected light from the refection region;

a reflection portion, on which the emission portion is mounted and which covers externally the refection region, for dissipating heat generated from the emission portion and for reflecting light passing through the refection region in a direction of the light output surface; and

a space formed between the light guiding member and the reflection portion.

2. The light emitting device according to claim 1, wherein:

the emission portion comprises a flip-chip mounted light emitting element.

3. The light emitting device according to claim 2, wherein:

the emission portion further comprises a glass material for sealing the light emitting element.

4. The light emitting device according to claim 3, wherein:

the light guiding member further comprises a parallel region formed on a surface thereof, adjacent to the refection region and parallel to the inputted light to the light input surface; and

the parallel region which allows light reflected by the reflection portion to pass therethrough.

5. The light emitting device according to claim 4, wherein:

the light guiding member further comprises a plurality of the refection regions and a plurality of the parallel regions; and

the plurality of the refection regions and the plurality of the parallel regions are arranged alternately and serially.

6. The light emitting device according to claim 5, wherein:

the emission portion comprises a plurality of the light emitting elements disposed at predetermined intervals.

7. The light emitting device according to claim 6, wherein:

the plurality of the light emitting elements are disposed linearly.

8. The light emitting device according to claim 6, wherein:

the plurality of the light emitting elements are disposed in a matrix arrangement.

9. The light emitting device according to claim 3, wherein:

the glass material includes a phosphor for wavelength-converting light emitted from the light emitting element.

10. The light emitting device according to claim 1, further comprising:

an insertion member between the emission portion and the reflection portion, the insertion member comprising a thermal expansion coefficient smaller than that of the reflection portion.

11. The light emitting device according to claim 1, wherein:

the reflection portion comprises an annular mounting portion on which a plurality of the emission portions are mounted, and a throughhole inside the annular mounting portion.

12. The light emitting device according to claim 11, wherein:

the reflection portion further comprises a heat dissipation fin inside the throughhole.

13. The light emitting device according to claim 1, wherein:

the reflection portion comprises a mounting portion on which a plurality of the emission portions are mounted, and which comprises a thermal conductivity equal to or higher than the reflection portion.

14. The light emitting device according to claim 1, further comprising:

a cover member that covers externally the light output surface of the light guiding member, comprises an opening for extracting therethrough light outputted from the light output surface, and is connected to the reflection portion.