MULTI-COLOR SEMICONDUCTOR LAMP

• US 3,875,456 A
• Filed: 04/04/1973
• Issued: 04/01/1975
• Est. Priority Date: 04/04/1972
• Status: Expired due to Term

• Current Assignee: Atsushi Suzuki, Shigekazu Minagawa, Tadashi Saitoh, Teruki Suzuki, Tsuyoshi Kano, Yoshiro Otomo
• Original Assignee: Atsushi Suzuki, Shigekazu Minagawa, Tadashi Saitoh, Teruki Suzuki, Tsuyoshi Kano, Yoshiro Otomo
• Inventors: Kano, Tsuyoshi, Suzuki, Atsushi, Suzuki, Teruki, Otomo, Yoshiro, Saitoh, Tadashi, Minagawa, Shigekazu
• Primary Examiner(s): Brody, Alfred L.
• Application Number:
  US05/347,660
• Time in Patent Office: 727 Days
• Field of Search: 313/110,18D,501 307/311 317/235N 250/211J 357/17,18,19,73
• US Class Current: 313/501
• 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: G08G 1/095 Traffic lights
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• CPC Class Codes: H01L 25/0756 Stacked arrangements of devices
• 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 2933/0091 Scattering means in or on the semiconductor body or semiconductor body package H01L33/22 takes precedence
• CPC Class Codes: H01L 33/504 Elements with two or more wavelength conversion materials
• CPC Class Codes: H01L 33/54 having a particular shape
• CPC Class Codes: H01L 33/60 Reflective elements
• CPC Class Codes: H05B 33/00 Electroluminescent light sources

Abstract

A multi-color semiconductor lamp comprising a plurality of light emitting diodes disposed close to one another and respectively emitting the light of different colors and a light scattering layer covering these light emitting diodes. With this device, light emitted from any one of the plurality of light emitting diodes is visible as if it were emitted from one and the same position. The present invention therefore, makes it possible to obtain clear multi-color indication with a small-size lamp which has heretofore been difficult.

Claims

1. A semiconductor lamp for emitting a plurality of colors of light as if from a single source of light comprising a plurality of light-emitting semiconductor diodes disposed closely adjacent one another in distinct and separate positions on a common support means and capable of emitting light of respectively different colors, a common light scattering layer covering said light-emitting diodes acting to disperse the light from said diodes to provide the appearance of a single source of light emitting said respectively different colors from the same position therein, and input terminal means for each of said diodes extending therefrom for receiving electrical input signals to selectively energize said diodes to transmit light of various colors through said light scattering layer.

2. A multi-color semiconductor lamp according to claim 1, wherein said light-emitting diodes include at least one light emitting diode emitting invisible light and a layer of flourescent material covering said one diode and responsive to said invisible light to emit visible light of a selective color.

3. A multi-color semiconductor lamp according to claim 1, wherein said light emitting diodes include at least a first such diode emitting visible light and at least a second such diode emitting invisible light;

and wherein at least said second such diode is covered with a layer of fluorescent material responsive to said invisible light to emit visible light of a selective color.

4. A multi-color semiconductor lamp according to claim 1, wherein said light-emitting diodes emit invisible light;

and wherein each such diode is covered by a layer of fluorescent material responsive to said invisible light to emit visible light of a predetermined color.

5. A multi-color semiconductor lamp according to claim 1, wherein at least one of said light-emitting diodes is a multiple p-n junction light-emitting diode capable of emitting light of a different color from each said p-n junction.

6. A multi-color semiconductor lamp according to claim 1, wherein said light scattering layer contains alumina powder.

7. A multi-color semiconductor lamp according to claim 1, wherein said light scattering layer is covered with a transparent material.

8. A multi-color semiconductor lamp according to claim 1, which further comprises a lens covering said light scattering layer.

9. A multi-color semiconductor lamp according to claim 1, wherein said support means comprises a light-reflecting layer defining a casing around said lamp with a light emitting opening opposite said light scattering layer.

10. The invention defined in claim 3, wherein said layer of fluorescent material comprises said light scattering layer.

11. The invention defined in claim 3, wherein said layer of fluorescent material is positioned between said second such diode and said light scattering layer.

12. The invention defined in claim 4, wherein said layer of fluorescent material over each said diode is positioned between said diode and said light scattering layer.

13. The invention defined in claim 4, wherein, for one of said diodes said light scattering layer comprises said fluorescent layer and for the remaining said diodes the said respective fluorescent layers for same are located between said diodes and said light scattering layer.

14. The invention defined in claim 1, wherein said light scattering layer contains powdered fluorescent material.

15. The invention defined in claim 1, wherein said light scattering layer comprises a body of ground glass.

16. The invention defined in claim 1, wherein said supporting means comprises a metal casing having a light emitting opening therein opposite said light scattering layer and lens means positioned across said openiNg in the provision of a modular semiconductor lamp;

and wherein said input terminal means are mounted on said support means adjacent said light emitting diodes.

17. The invention defined in claim 16, wherein said casing further includes a reflective internal surface and said lens means comprises a transparent layer filling said casing, covering said light scattering layer and having a lens-shaped external surface thereon.

18. A semiconductor lamp for emitting a pluralty of colors of light as if from a single source of light comprising a plurality of light-emitting semiconductor diodes disposed closely adjacent one another in distinct and separate positions on a common support means and capable of emitting light of respectively different colors, a common light scattering layer covering said light-emitting diodes acting to disperse the light from said diodes to provide the appearance of a single source of light emitting different colors from the same position therein, and input terminal means for each of said diodes extending therefrom for receiving electrical input signals to selectively simultaneously energize at least two of said diodes to transmit light of various blends of colors through said light scattering layer.