Light emitting element, lighting device and surface emission illuminating device using it

• US 20060175625A1
• Filed: 05/28/2003
• Published: 08/10/2006
• Est. Priority Date: 05/28/2002
• Status: Abandoned Application

• Current Assignee: Asahi Matsushita Electric Works Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Asahi Matsushita Electric Works Ltd. (Panasonic Holdings Corporation)
• Inventors: Yamaguchi, Masao, Yokotani, Ryoji
• Application Number:
  US10/514,723
• Publication Number:
  US 20060175625A1
• Time in Patent Office: Days
• US Class Current: 257/95
• CPC Class Codes: G02B 5/0231 the surface having microprismatic or micropyramidal shape macroscopic prism arrays G02B5/045
• CPC Class Codes: G02B 5/0278 used in transmission
• CPC Class Codes: H01L 33/20 with a particular shape, e.g. curved or truncated substrate
• CPC Class Codes: H01L 33/22 Roughened surfaces, e.g. at the interface between epitaxial layers
• CPC Class Codes: H01L 33/44 characterised by the coatings, e.g. passivation layer or anti-reflective coating
• 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 33/54 having a particular shape

Abstract

In a non-sealed type light emitting device in which a diode structure on a face of a transparent substrate by lamination of an n-type semiconductor layer and a p-type semiconductor layer, an outer face of the transparent substrate is made not in parallel with a most outer face of the diode structure by, for example, being slanted so as to increase a light taking efficiency from an exit face of light. An incident angle of a light beam entering into an exit face of light is gradually reduces by repeating total reflection on these two faces so as to make is smaller than a critical angle, and to emit the light beams outward of the light emitting device.

Claims

1. A non-sealed type light emitting device having a diode structure which is formed by lamination of an n-type semiconductor layer and a p-type semiconductor layer on a face of a transparent substrate, and characterized by that an exit face of light is not in parallel with a face among respective faces of the diode structure which is opposite to the transparent substrate.

2. The light emitting device in accordance with claim 1, characterized by that a face of the transparent substrate facing the face on which the diode structure serves as the exit face of light;

and it is a slanted face with respect to the face among respective faces of the diode structure which is opposite to the transparent substrate, a rough face, a substantially pyramid or cone shape, a substantially spherical shape, a face on which a plurality of convex portions of substantially pyramid or cone shape or substantially spherical shape is arranged, or a substantially cylindrical shape.

3. The light emitting device in accordance with claim 2, characterized by that the exit face of light is substantially pyramid or cone shape;

and a ratio of a height with respect to a maximum width of a bottom face of the substantially pyramid or cone shape is equal to or larger than about 0.4 and equal to or smaller than about 4.5.

4. The light emitting device in accordance with claim 2, characterized by that the exit face of light is substantially spherical shape;

and a ratio of a height with respect to a diameter of a bottom face of the substantially spherical shape is equal to or larger than about 0.3 and equal to or smaller than about 0.5.

5. The light emitting device in accordance with claim 1, characterized by that the transparent substrate is configured by a parallel plate made of a first material and having a first face on which the diode structure is formed and a second face in parallel with the first face, and a transparent member made of a second material and having a third face connected with the second face of the parallel plate and a fourth face opposite to the third face;

the fourth of the transparent member is not in parallel with the face among respective faces of the diode structure which is opposite to the transparent substrate; and

the fourth face of the transparent member serves as the exit face of light.

6. The light emitting device in accordance with claim 5, characterized by that the fourth face of the transparent member is a slanted face with respect to the face among respective faces of the diode structure which is opposite to the transparent substrate, a rough face, a substantially pyramid or cone shape, a substantially spherical shape, a face on which a plurality of convex portions of substantially pyramid or cone shape or substantially spherical shape is arranged, or a substantially cylindrical shape.

7. The light emitting device in accordance with claim 1, characterized by that a transparent member connected with the face among respective faces of the diode structure which is opposite to the transparent substrate is further comprised, and a face of the transparent member opposite to a connecting face with the diode structure serves as the exit face of light.

8. The light emitting device in accordance with claim 7, characterized by that the exit face of light is a slanted face with respect to the face among respective faces of the diode structure which is opposite to the transparent substrate, a rough face, a substantially pyramid or cone shape, a substantially spherical shape, a face on which a plurality of convex portions of substantially pyramid or cone shape or substantially spherical shape is arranged, or a substantially cylindrical shape.

9. A lighting apparatus comprising a non-sealed type light emitting apparatus mounted on a mounting substrate, and a fluorescent member disposed in front of an exit face of light of the light emitting device, which is excited by a light emitted from the light emitting device and emits a light of different wavelength from excitation wavelength, and characterized by that the light emitting device has a diode structure which is formed by lamination of an n-type semiconductor layer and a p-type semiconductor layer on a face of a transparent substrate, and the exit face of light is not in parallel with a face among respective faces of the diode structure which is opposite to the transparent substrate.

10. The lighting apparatus in accordance with claim 9, characterized by that an optical member comprising the fluorescent member on a surface or inside is detachable mounted on the mounting substrate.

11. The lighting apparatus in accordance with claim 9, characterized by that the optical member has a convex lens shape.

12. The lighting apparatus in accordance with claim 9, characterized by that the light emitting device is mounted on a bottom face of a concave portion formed on the mounting substrate;

and a face of the transparent member facing the light emitting device is substantially the same size as that of an opening of the concave portion.

13. The lighting apparatus in accordance with claim 12, characterized by that an inner face of the concave portion is firmed substantially paraboloid or substantially ellipsoidal, and the light emitted from the light emitting device is reflected on the inner face of the concave portion so as to enter it into the fluorescent member.

14. The lighting apparatus in accordance with claim 12, characterized by that a transparent resin is filled in the concave portion in a manner so that at least a part of the exit face of the light emitting device.

15. The lighting apparatus in accordance with claim 14, characterized by that a member having a function serving as the exit face of light of the light emitting device and the transparent resin filled in the concave portion are substantially the same material.

16. The lighting apparatus in accordance with claim 14, characterized by that the transparent substrate is configured by a parallel plate made of a first material, and a transparent member made of a second material and connected to the parallel plate;

a non-connection face of the transparent member serves as the exit face of light; and

the parallel plate and the transparent member are closely disposed via a transparent connection layer made of a material having an intermittent refraction index between the refraction index of the first material and the refraction index of the second material.

17. The lighting apparatus in accordance with claim 15, characterized by that at least a part of the member having the function serving as the exit face of light of the light emitting device is protruded outward from the exit face of light toward the transparent resin filled in the concave portion.

24. The light emitting apparatus in accordance with claim 9, characterized by that a face of the transparent substrate facing the face on which the diode structure serves as the exit face of light;

and it is a slanted face with respect to the face among respective faces of the diode structure which is opposite to the transparent substrate, a rough face, a substantially pyramid or cone shape, a substantially spherical shape, a face on which a plurality of convex portions of substantially pyramid or cone shape or substantially spherical shape is arranged, or a substantially cylindrical shape.

25. The light emitting apparatus in accordance with claim 24, characterized by that the exit face of light is substantially pyramid or cone shape;

and a ratio of a height with respect to a maximum width of a bottom face of the substantially pyramid or cone shape is equal to or larger than about 0.4 and equal to or smaller than about 4.5.

26. The light emitting apparatus in accordance with claim 24, characterized by that the exit face of light is substantially spherical shape;

and a ratio of a height with respect to a diameter of a bottom face of the substantially spherical shape is equal to or larger than about 0.3 and equal to or smaller than about 0.5.

27. The light emitting apparatus in accordance with claim 9, characterized by that the transparent substrate is configured by a parallel plate made of a first material and having a first face on which the diode structure is formed and a second face in parallel with the first face, and a transparent member made of a second material and having a third face connected with the second face of the parallel plate and a fourth face opposite to the third face;

the fourth of the transparent member is not in parallel with the face among respective faces of the diode structure which is opposite to the transparent substrate; and

the fourth face of the transparent member serves as the exit face of light.

28. The light emitting apparatus in accordance with claim 27, characterized by that the fourth face of the transparent member is a slanted face with respect to the face among respective faces of the diode structure which is opposite to the transparent substrate, a rough face, a substantially pyramid or cone shape, a substantially spherical shape, a face on which a plurality of convex portions of substantially pyramid or cone shape or substantially spherical shape is arranged, or a substantially cylindrical shape.

29. The light emitting apparatus in accordance with claim 9, characterized by that a transparent member connected with the face among respective faces of the diode structure which is opposite to the transparent substrate is further comprised, and a face of the transparent member opposite to a connecting face with the diode structure serves as the exit face of light.

30. The light emitting apparatus in accordance with claim 29, characterized by that the exit face of light is a slanted face with respect to the face among respective faces of the diode structure which is opposite to the transparent substrate, a rough face, a substantially pyramid or cone shape, a substantially spherical shape, a face on which a plurality of convex portions of substantially pyramid or cone shape or substantially spherical shape is arranged, or a substantially cylindrical shape.

18. A surface emitting illumination apparatus comprising one or a plurality of non-sealed type light emitting apparatuses mounted on a mounting substrate, and a fluorescent member which is excited by a light emitted from the light emitting device and emits a light of different wavelength from excitation wavelength, and characterized by that the light emitting device has a diode structure which is formed by lamination of an n-type semiconductor layer and a p-type semiconductor layer on a face of a transparent substrate, and the exit face of light is not in parallel with a face among respective faces of the diode structure which is opposite to the transparent substrate.

19. The surface emitting illumination apparatus in accordance with claim 18, characterized by that a light guide member is provided between the exit face of light of the light emitting device and the fluorescent member.

20. The surface emitting illumination apparatus in accordance with claim 18, characterized by that a cross-section of the exit face of light of the light emitting device in a predetermined direction is formed in a manner so that a width thereof becomes narrower corresponding to a distance from a light emitting face of the light emitting device.

21. The surface emitting illumination apparatus in accordance with claim 20, characterized by that the exit face of light of the light emitting device is substantially pyramid shape or cone shape, combination of a plurality of slant faces or substantially cylindrical shape.

22. The surface emitting illumination apparatus in accordance with claim 20, characterized by that a concave portion having substantially the same shape as the exit face of light of the light emitting device is formed at a position facing each light emitting device on a face of the light guide member facing the light emitting device;

and at least a part of the exit face of light of the light emitting device is inserted into the concave portion.

23. The surface emitting illumination apparatus in accordance with claim 19, characterized by that the light emitting device is disposed for facing a side face perpendicular to an exit face of light of the light guide member;

and the fluorescent member is disposed for facing the exit face of light of the light guide member.