Solid state light emitting devices including adjustable scotopic / photopic ratio

• US 9,030,103 B2
• Filed: 02/08/2013
• Issued: 05/12/2015
• Est. Priority Date: 02/08/2013
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Pickard, Paul Kenneth
• Primary Examiner(s): Owens, Douglas W
• Assistant Examiner(s): Sathiraju, Srinivas
• Application Number:
  US13/763,576
• Publication Number:
  US 20140225514A1
• Time in Patent Office: 823 Days
• Field of Search: 315/152
• US Class Current: 315/152
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48465 the other connecting portion not on the bonding area being a wedge bond, i.e. ball-to-wedge, regular stitch
• CPC Class Codes: H01L 25/0753 the devices being arranged next to each other
• 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 2924/00014 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 33/62 Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H05B 45/00 Circuit arrangements for operating light-emitting diodes [LED]
• CPC Class Codes: H05B 45/20 Controlling the colour of the light
• CPC Class Codes: H05B 45/28 using temperature feedback
• CPC Class Codes: H05B 45/325 Pulse-width modulation [PWM]

Abstract

Solid state light emitting devices include multiple LED components separately arranged to generate spectral output having different ratios of scotopic to photopic light (S/P ratios) but similar chromaticities preferably within seven MacAdam ellipses. A light emitting device may be controlled to permit transitioning between different modes of operation of multiple LED components, with aggregated output of different modes having different S/P ratios but similar chromaticities. Multiple LED components of a light emitting device may be simultaneously controlled with different dimming profiles to effect increased color rendering at maximum emissive output of the apparatus, and to effect increased aggregated S/P ratio at minimum emissive output of the device.

Claims

1. A light emitting apparatus comprising:

a first LED component arranged to generate a first spectral output including a first ratio of scotopic to photopic light (first S/P ratio), and including a first chromaticity; and

a second LED component arranged to generate a second spectral output including a second ratio of scotopic to photopic light (second S/P ratio), and including a second chromaticity;

wherein the first chromaticity and the second chromaticity differ by no more than seven MacAdam ellipses; and

wherein the first S/P ratio is at least 20% greater than the second S/P ratio.

2. A light emitting apparatus according to claim 1, wherein the first chromaticity and the second chromaticity differ by no more than four MacAdam ellipses.

3. A light emitting apparatus according to claim 1, wherein the first S/P ratio is at least 50% greater than the second S/P ratio.

4. A light emitting apparatus according to claim 1, wherein the first S/P ratio is at least 100% greater than the second S/P ratio.

5. A light emitting apparatus according to claim 1, wherein the first LED component comprises a first LED including a first peak wavelength, the second LED component comprises a second LED including a second peak wavelength, and the first peak wavelength differs from the second peak wavelength by at least 10 nm.

6. A light emitting apparatus according to claim 1, wherein the first LED component comprises a first LED arranged to stimulate emissions of at least one first lumiphor, wherein either the first LED or the at least one first lumiphor comprises a peak wavelength in a range of from 481 nm to 505 nm.

7. A light emitting apparatus according to claim 1, wherein:

the first LED component comprises a first LED including a peak wavelength in a range of from 481 nm to 505 nm arranged to stimulate emissions of at least one first lumiphor including a peak wavelength in a range of from 591 nm to 690 nm; and

the second LED component comprises a second LED including a peak wavelength in a range of from 430 nm to 480 nm arranged to stimulate emissions of at least one second lumiphor including a peak wavelength in a range of from 561 nm to 590 nm.

8. A light emitting apparatus according to claim 1, wherein:

the first LED component comprises a first LED including a peak wavelength in a range of from 430 nm to 480 nm arranged to stimulate emissions of at least one first lumiphor including a peak wavelength in a range of from 481 nm to 505 nm, and the first LED component comprises an additional LED including a peak wavelength in a range of from 591 nm to 690 nm; and

the second LED component comprises a second LED including a peak wavelength in a range of from 430 nm to 480 nm arranged to stimulate emissions of at least one second lumiphor including a peak wavelength in a range of from 561 nm to 590 nm.

9. A light emitting apparatus according to claim 1, wherein:

the first LED component comprises a first LED including a peak wavelength in a range of from 430 nm to 480 nm arranged to stimulate emissions of at least one first lumiphor including a peak wavelength in a range of from 481 nm to 505 nm, and comprises an additional LED including a peak wavelength in a range of from 506 nm to 560 nm arranged to stimulate emissions of at least one additional lumiphor including a peak wavelength in a range of from 591nm to 690 nm; and

the second LED component comprises a second LED including a peak wavelength in a range of from 430 nm to 480 nm arranged to stimulate emissions of at least one second lumiphor including a peak wavelength in a range of from 561 nm to 590 nm.

10. A light emitting apparatus according to claim 1, wherein:

the first LED component comprises a first LED including a peak wavelength in a range of from 380 nm to 425 nm arranged to stimulate emissions of at least one first lumiphor including a peak wavelength in a range of from 481 nm to 505 nm, and comprises an additional LED including a peak wavelength in a range of from 591 nm to 690 nm; and

the second LED component comprises a second LED including a peak wavelength in a range of from 430 nm to 480 nm arranged to stimulate emissions of at least one second lumiphor including a peak wavelength in a range of from 561 nm to 590 nm.

11. A light emitting apparatus according to claim 1, wherein:

the first LED component comprises a first LED including a peak wavelength in a range of from 380 nm to 425 nm arranged to stimulate emissions of at least one first lumiphor including a peak wavelength in a range of from 481 nm to 505 nm, and the first LED component comprises an additional LED including a peak wavelength in a range of from 506 nm to 560 nm arranged to stimulate emissions of at least one additional lumiphor including a peak wavelength in a range of from 591 nm to 690 nm; and

the second LED component comprises a second LED including a peak wavelength in a range of from 430 nm to 480 nm arranged to stimulate emissions of at least one second lumiphor including a peak wavelength in a range of from 561 nm to 590 nm.

12. A light emitting apparatus according to claim 1, wherein:

the first LED component comprises a first LED including a peak wavelength in a range of from 481 nm to 505 nm arranged to stimulate emissions of at least one first lumiphor including a peak wavelength in a range of from 561 nm to 590 nm; and

the second LED component comprises a second LED including a peak wavelength in a range of from 430 nm to 480 nm arranged to stimulate emissions of at least one second lumiphor including a peak wavelength in a range of from 591 nm to 690 nm.

13. A light emitting apparatus according to claim 1, wherein:

the first LED component comprises a first LED including a peak wavelength in a range of from 481 nm to 505 nm arranged to stimulate emissions of at least one first lumiphor including a peak wavelength in a range of from 561 nm to 590 nm; and

the second LED component comprises a second LED including a peak wavelength in a range of from 506 nm to 560 nm arranged to stimulate emissions of at least one second lumiphor including a peak wavelength in a range of from 591 nm to 690 nm.

14. A light emitting apparatus according to claim 1, further comprising at least one control circuit arranged to independently supply current to the first LED component and the second LED component.

15. A light emitting apparatus according to claim 14, further comprising at least one element operatively coupled to the at least one control circuit to affect dimming of the first LED component and the second LED component, wherein the at least one element is selected from the group consisting of a user input element, a timer, and a photosensor.

16. A light emitting apparatus according to claim 1, comprising at least one of the following features:

a single leadframe arranged to conduct electrical power to the first LED component and the second LED component;

a single reflector arranged to reflect at least a portion of light emanating from each of the first LED component and the second LED component;

a single submount supporting the first LED component and the second LED component; and

a single lens arranged to transmit at least a portion of light emanating from each of the first LED component and the second LED component.

17. A light emitting apparatus according to claim 1, wherein each of the first LED component and the second LED component is separately arranged to output light having a color temperature in a range of from 2700K to 5000K.

18. A method comprising illuminating an object, a space, or an environment, utilizing a light emitting apparatus according to claim 1.

19. A light emitting apparatus comprising:

a first LED component arranged to generate a first spectral output including a first ratio of scotopic to photopic light (first S/P ratio);

a second LED component arranged to generate a second spectral output including a second ratio of scotopic to photopic light (second S/P ratio) that differs from the first S/P ratio; and

at least one control circuit arranged to permit transitioning between at least two predefined modes of operating the first LED component and the second LED component;

wherein;

the at least two predefined modes include a first operating mode and a second operating mode;

the first operating mode is arranged to generate aggregated emissions from the light emitting apparatus according to a first aggregated emission profile including a first aggregated ratio of scotopic to photopic light (first aggregated S/P ratio) and a first aggregated chromaticity;

the second operating mode is arranged to generate aggregated emissions from the light emitting apparatus according to a second aggregated emission profile including a second aggregated ratio of scotopic to photopic light (second aggregated S/P ratio) and a second aggregated chromaticity;

the first aggregated S/P ratio is at least 20% greater than the second aggregated S/P ratio; and

the first aggregated chromaticity differs from the second aggregated chromaticity by no more than seven MacAdam ellipses.

20. A light emitting apparatus according to claim 19, wherein the first aggregated S/P ratio is at least 50% greater than the second aggregated S/P ratio.

21. A light emitting apparatus according to claim 19, wherein the first aggregated S/P ratio is at least 100% greater than the second aggregated S/P ratio.

22. A light emitting apparatus according to claim 19, wherein the first aggregated chromaticity differs from the second aggregated chromaticity by no more than four MacAdam ellipses.

23. A light emitting apparatus according to claim 19, wherein the at least two predefined modes includes three or more predefined modes.

24. A light emitting apparatus according to claim 19, wherein the at least one control circuit is arranged to permit gradual transitioning from the first operating mode to the second operating mode according to at least one of the following conditions (i) or (ii):

(i) over a time period of at least about ten seconds, and (ii) utilizing at least four intermediate transition steps.

25. A light emitting apparatus according to claim 19, wherein each of the first LED component and the second LED component is separately arranged to output light having a color temperature in a range of from 2700K to 5000K.

26. A light emitting apparatus according to claim 19, wherein the first LED component comprises a first LED including a first peak wavelength, the second LED component comprises a second LED including a second peak wavelength, and the first peak wavelength differs from the second peak wavelength by at least 10 nm.

27. A light emitting apparatus according to claim 19, wherein the first LED component comprises a first LED arranged to stimulate emissions of at least one first lumiphor, wherein either the first LED or the at least one first lumiphor comprises a peak wavelength in a range of from 481 nm to 505 nm.

28. A light emitting apparatus according to claim 19, further comprising at least one element operatively coupled to the control circuit to activate switching between different modes of the at least two predefined modes, wherein the at least one element is selected from the group consisting of a user input element, a timer, and a photosensor.

29. A light emitting apparatus according to claim 19, comprising at least one of the following features:

a single leadframe arranged to conduct electrical power to the first LED component and the second LED component;

a single reflector arranged to reflect at least a portion of light emanating from each of the first LED component and the second LED component;

a single submount supporting the first LED component and the second LED component; and

a single lens arranged to transmit at least a portion of light emanating from each of the first LED component and the second LED component.

30. A method comprising illuminating an object, a space, or an environment, utilizing a light emitting apparatus according to claim 19.

31. A light emitting apparatus comprising:

a first LED component arranged to generate a first spectral output including a first ratio of scotopic to photopic light (first S/P ratio);

a second LED component arranged to generate a second spectral output including a second ratio of scotopic to photopic light (second S/P ratio) that differs from the first S/P ratio; and

at least one control circuit arranged to control operation of the first LED component according to a first dimming profile and to simultaneously control operation of the second LED component according to a second dimming profile, wherein the first dimming profile differs from the second dimming profile to effect increased color rendering index of aggregated emissions of the light emitting apparatus at maximum emissive output of the light emitting apparatus, and to effect increased aggregated S/P ratio of aggregated emissions of the light emitting apparatus at minimum emissive output of the light emitting apparatus.

32. A light emitting apparatus according to claim 31, wherein the at least one control circuit comprises a first control circuit arranged to control operation of the first LED component, and comprises a second control circuit arranged to control operation of the second LED component.

33. A light emitting apparatus according to claim 31, wherein the at least one control circuit is configured to provide a linear relationship of aggregate current supplied to the first LED component and the second LED component versus aggregate dimming level for the light emitting apparatus.

34. A light emitting apparatus according to claim 31, wherein the at least one control circuit is configured to provide an exponential relationship of aggregate current supplied to the first LED component and the second LED component versus aggregate dimming level for the light emitting apparatus.

35. A light emitting apparatus according to claim 31, wherein the minimum emissive output of the light emitting apparatus includes operation of both the first LED component and the second LED component.

36. A light emitting apparatus according to claim 31, wherein the aggregated S/P ratio of aggregated emissions of the light emitting apparatus at maximum emissive output of the light emitting apparatus is at least 50% greater than the aggregated S/P ratio of aggregated emissions of the light emitting apparatus at minimum emissive output of the light emitting apparatus.

37. A light emitting apparatus according to claim 31, wherein the aggregated S/P ratio of aggregated emissions of the light emitting apparatus at maximum emissive output of the light emitting apparatus is at least 100% greater than the aggregated S/P ratio of aggregated emissions of the light emitting apparatus at minimum emissive output of the light emitting apparatus.

38. A light emitting apparatus according to claim 31, wherein a chromaticity of aggregated emissions of the light emitting apparatus at maximum emissive output of the light emitting apparatus differs by no more than seven MacAdam ellipses from a chromaticity of aggregated emissions of the light emitting apparatus at minimum emissive output of the light emitting apparatus.

39. A light emitting apparatus according to claim 31, wherein each of the first LED component and the second LED component is separately arranged to output light having a color temperature in a range of from 2700K to 5000K.

40. A light emitting apparatus according to claim 31, further comprising at least one element operatively coupled to the at least one control circuit to affect dimming of the first LED component and the second LED component, wherein the at least one element is selected from the group consisting of a user input element, a timer, and a photosensor.

41. A light emitting apparatus according to claim 31, comprising at least one of the following features:

a single leadframe arranged to conduct electrical power to the first LED component and the second LED component;

a single reflector arranged to reflect at least a portion of light emanating from each of the first LED component and the second LED component;

a single submount supporting the first LED component and the second LED component; and

a single lens arranged to transmit at least a portion of light emanating from each of the first LED component and the second LED component.

42. A light emitting apparatus comprising:

a first LED component arranged to generate a first spectral output including a first ratio of scotopic to photopic light (first S/P ratio);

a second LED component arranged to generate a second spectral output including a second ratio of scotopic to photopic light (second S/P ratio), wherein the first S/P ratio is at least 20% greater than the second S/P ratio; and

at least one control circuit arranged to independently supply current to the first LED component and the second LED component;

wherein the light emitting apparatus comprises at least one of the following features (i) and (ii);

(i) the light emitting apparatus is adapted to increase relative spectral output in a wavelength range below 507 nm when the light emitting apparatus is operated at an aggregated emissive output of less than 50% of maximum aggregated emissive output of the light emitting apparatus, in comparison to relative spectral output in a wavelength range below 507 nm when the light emitting apparatus is operated at maximum aggregated emissive output; and

(ii) the light emitting apparatus is adapted to increase correlated color temperature of aggregated emissions by at least about 200K when the light emitting apparatus is operated at an aggregated emissive output of less than 50% of maximum aggregated emissive output, relative to correlated color temperature of aggregated emissions at maximum aggregated emissive output.

43. A light emitting apparatus according to claim 42, being adapted to increase relative spectral output in a wavelength range below 507 nm when the light emitting apparatus is operated at an aggregated emissive output of less than 50% of maximum aggregated emissive output of the light emitting apparatus, in comparison to relative spectral output in a wavelength range below 507 nm when the light emitting apparatus is operated at maximum aggregated emissive output.

44. A light emitting apparatus according to claim 43, wherein relative spectral output in a wavelength range below 507 nm is increased by at least about 20% when the light emitting apparatus is operated at an aggregated emissive output of less than 50% of maximum aggregated emissive output of the light emitting apparatus, in comparison to relative spectral output in a wavelength range below 507 nm when the light emitting apparatus is operated at maximum aggregated emissive output.

45. A light emitting apparatus according to claim 42, being adapted to increase correlated color temperature of aggregated emissions by at least about 200K when the light emitting apparatus is operated at an aggregated emissive output of less than 50% of maximum aggregated emissive output, relative to correlated color temperature of aggregated emissions at maximum aggregated emissive output.

46. A light emitting apparatus according to claim 42, wherein the first LED component includes a first chromaticity, the second LED component includes a second chromaticity, and the first chromaticity and the second chromaticity differ by no more than seven MacAdam ellipses.