LED flashlight

• US 20060039139A1
• Filed: 08/20/2004
• Published: 02/23/2006
• Est. Priority Date: 08/20/2004
• Status: Active Grant

• Current Assignee: Anthony Maglica, John K O'Farrell, Stacey H. West
• Original Assignee: Anthony Maglica, John K O'Farrell, Stacey H. West
• Inventors: West, Stacey H., O'Farrell, John K., Maglica, Anthony
• Granted Patent: US 8,733,966 B2
• Time in Patent Office: Days
• US Class Current: 362/202
• CPC Class Codes: F21L 4/00 Electric lighting devices with self-contained electric batteries or cells
• CPC Class Codes: F21L 4/027 the light sources being a LED
• CPC Class Codes: F21V 13/045 for portable lighting devices
• CPC Class Codes: F21V 14/045 in portable lighting devices
• CPC Class Codes: F21V 23/0428 the switch being part of, or disposed on the lamp head portion thereof
• CPC Class Codes: F21V 29/507 of means for protecting lighting devices from damage, e.g. housings
• CPC Class Codes: F21V 29/70 characterised by passive heat-dissipating elements, e.g. heat-sinks
• CPC Class Codes: F21V 3/00 Globes; Bowls; Cover glasses with refracting properties F21V5/00; with reflecting properties F21V7/00; characterised by cooling arrangements F21V29/506
• CPC Class Codes: F21V 31/005 Sealing arrangements therefor
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 7/06 with parabolic curvature
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/395 Linear regulators
• CPC Class Codes: H05B 45/56 involving measures to prevent abnormal temperature of the LEDs
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A lighting device with improved optical performance and efficiency is provided. The lighting device includes a source of energy, a light source, a reflector and a holder. The reflector has a first open end, a second end, and a parabolic profile extending between the first open end and second end. The focus of the parabolic profile is located outside of the profile. The reflector may also be movable relative to the light source. The lighting device may include a circuit that delivers a pulsed or thermally compensated pulsed current to the light source. The light device may also include a heat sink housing.

Claims

1. A lighting device comprising:

a source of energy;

a light source coupled to said source of energy;

a reflector that reflects light including a first open end, a second end, and a parabolic profile extending between said first open end and said second end, wherein the focus of said parabolic profile is located outside said parabolic profile;

a holder that holds said light source relative to said reflector such that light generated by said light source is reflected by said reflector.

2. A lighting device of claim 1, wherein the relative position of said light source and said reflector is variable.

3. A lighting device of claim 1, wherein said first open end is larger than said second end, wherein the ratio between the distance of the second end from the vertex of said parabolic profile and the distance of the focus from the vertex of said parabolic profile is greater than 1.5:

1.

4. A lighting device of claim 1, wherein said first open end is larger than said second end, wherein the ratio between the distance of the second end from the vertex of said parabolic profile and the distance of the focus from the vertex of said parabolic profile is less than 6.5:

1.

5. A lighting device of claim 1, wherein said first open end is larger than said second end, wherein the ratio between the distance of the second end from the vertex of said parabolic profile and the distance of the focus from the vertex of said parabolic profile is between 3.0:

1 and 3.4;

1.

6. A lighting device of claim 1, wherein said first open end is larger than said second end, wherein the ratio between the distance of the second end from the vertex of said parabolic profile and the distance of the focus from the vertex of said parabolic profile is 3.2:

1.

7. A lighting device of claim 1, wherein said parabolic profile substantially conforms to a profile according to the equation r²=4 fz, wherein “

r”

is the radius of the parabolic profile normal to the axis of the reflector, “

f”

is the distance between the focus and the vertex of said parabolic profile set at 0.035 inch, and “

z”

is the distance in the reflector axis direction.

8. A lighting device of claim 1, wherein said light source is an LED lamp.

9. A lighting device of claim 8, wherein said LED lamp substantially radiates light at an angle of less than 180°

.

10. A lighting device of claim 1 further including a head assembly coupled to a main housing, wherein said reflector is mounted to said head assembly, wherein said main housing contains said source of energy, and wherein rotating said head assembly relative to said main housing opens or closes an electrical path between said source of energy and said light source.

11. A lighting device of claim 1 further including a main housing and an electrical circuit, wherein said electrical circuit includes a heat sink housing, wherein said heat sink housing receives said light source and thermally couples said light source to said main housing.

12. A lighting device of claim 11, wherein said heat sink housing electrically couples said light source to said main housing.

13. A lighting device of claim 1 further including a current modulating circuit coupled to said source of energy, wherein said current modulating circuit delivers a pulsed current to said light source.

14. A lighting device of claim 13, wherein said current modulating circuit includes a pulse generator, a power switch and a temperature responsive resistor, wherein said current modulating circuit delivers a thermally compensated pulsed current to said light source.

15. A lighting device of claim 1 further including a current modulating circuit coupled to said source of energy, wherein said current modulating circuit delivers a thermally compensated current to said light source.

16. A lighting device of claim 1 further including means for delivering a thermally compensated pulsed current signal to said light source.

17. A lighting device of claim 1 further including a tail cap, a main housing and an energy source assembly, wherein said tail cap attaches to said main housing, wherein said main housing receives said energy source assembly, wherein said energy source assembly receives said source of energy and electrically couples said source of energy to said main housing without conducting electricity through said tail cap.

18. A flashlight comprising:

a portable source of energy;

an LED lamp that substantially radiates light spherically over an angle less than 180°

coupled to the portable source of energy; and

a parabolic reflector that reflects light radiated by said LED lamp, said reflector including a first open end, a second open end and an axis extending between said ends, wherein the focus of said parabolic reflector is not located between said first open end and said second open end, wherein the focal length is between 0.020-0.050 inch.

19. A flashlight of claim 18, wherein said reflector is movable in a direction parallel to the principal axis of said parabolic reflector.

20. A flashlight comprising:

a portable source of power;

a light source coupled to said portable source of power including an LED and a lens, wherein said lens is arranged over the LED such that light substantially radiates from said light source at an angle less than 180°

relative to the LED position; and

a movable parabola shaped reflector for reflecting light radiating from said light source including a first open end, a second open end, and a parabolic profile extending between the first open end and the second open end, wherein the focus of the parabola is located outside the parabolic profile.

21. A flashlight of claim 20, wherein the reflector is movable in a direction parallel to the principal axis of the parabola.

22. A flashlight of claim 20 further including a heat sink thermally coupled to said light source.

23. A flashlight comprising:

a source of energy;

a light source coupled to said source of energy;

a reflector for reflecting light from said light source including a first open end, a second open end, and a parabolic profile extending between said first open end and said second open end, said first open end adapted to emit a light beam, wherein the focus of said parabolic profile is not located between the first open end and the second open end; and

a current modulating circuit coupled to said light source, wherein said current modulating circuit delivers a pulsed current to said light source.

24. A flashlight of claim 23, wherein said current modulating circuit includes pulse generator and a power switch.

25. A flashlight of claim 24, wherein said pulse generator includes a comparator.

26. A flashlight of claim 24, wherein said power switch is a transistor.

27. A flashlight of claim 23, wherein said current modulating circuit modulates said pulsed current according to heat generated by said light source.

28. A flashlight of claim 23, wherein said current modulating circuit adjusts the duty cycle of said pulsed signal depending on the temperature of said light source.

29. A flashlight of claim 23, wherein said current modulating circuit includes a temperature responsive resistor that detects the heat generated by said light source.

30. A flashlight of claim 29, wherein said temperature responsive resistor is a thermistor.

31. A flashlight comprising:

a portable source of energy;

an LED lamp that substantially radiates light spherically over an angle less than 180°

coupled to said portable source of energy; and

a reflector that reflects light radiated by said LED lamp including a first open end, a second open end, and a parabolic profile extending between said first open end and said second open end, said parabolic profile conforming to a profile according to the equation r²=4 fz, wherein “

r”

is the radius of the parabolic profile normal to the axis of the reflector, “

f”

is the distance between the focal point and the vertex of said parabolic profile set at between 0.020-0.050 inch, and “

z”

is the distance in the reflector axis direction;

wherein said first open end has a diameter larger than said second open end, wherein said second open end has a diameter between 0.20-0.30 inch.

32. A lighting device of claim 31, wherein said first open end is larger than said second end, wherein the ratio between the distance of the second end from the vertex of said parabolic profile and the distance of the focus from the vertex of said parabolic profile is greater than 1.5:

1.

33. A flashlight of claim 31, wherein said first end has a diameter of 0.70-0.80 inch.

34. A flashlight comprising:

a portable source of energy;

an LED lamp including a first lead and a second lead; and

an electrical circuit including a heat sink housing that electrically couples said first lead and said portable source of energy, wherein said heat sink housing is thermally coupled to said LED lamp to substantially dissipate heat generated therefrom.

35. A flashlight of claim 34 further including a main housing adapted to contain said portable source of energy, wherein said heat sink housing is thermally coupled to said main housing.

36. An energy source assembly comprising:

a plurality of energy sources; and

a housing adapted to receive said plurality of energy sources, said housing including a plurality of conductors, a first electrode, a second electrode and an outer feature;

wherein said plurality of conductors are selectively disposed to electrically couple said plurality of energy sources in an electrical circuit arrangement, wherein said electrical circuit arrangement includes a first terminal and a second terminal, wherein said first terminal is coupled to said first electrode, wherein said second terminal is coupled to said second electrode, and wherein said second electrode is disposed about the outer feature of said housing.

37. An energy source assembly of claim 36, wherein said housing includes receptacles arranged to hold said plurality of energy sources in a side-by-side arrangement.

38. An energy source assembly of claim 37, wherein said plurality of energy sources is a plurality of batteries.

39. An energy source assembly of claim 36, wherein said electrical circuit arrangement is a series circuit.

40. An energy source assembly of claim 36, wherein said electrical circuit arrangement is a parallel circuit.

41. An energy source assembly of claim 36, wherein said plurality of energy sources is a plurality of batteries.

42. A lighting device comprising:

an energy source assembly including a plurality of energy sources and a housing, said housing adapted to receive said plurality of energy sources, said housing having a plurality of conductors, a first electrode, a second electrode and an outer feature, wherein said plurality of conductors are selectively disposed to electrically couple said plurality of energy sources in an electrical circuit arrangement, wherein said electrical circuit arrangement includes a first terminal and a second terminal, wherein said first terminal is coupled to said first electrode, wherein said second terminal is coupled to said second electrode, and wherein said second electrode is disposed about the outer feature of said housing;

a light source coupled to said plurality of energy sources; and

a barrel configured to receive said energy source assembly, wherein said barrel is suitable to conduct electricity;

wherein said second electrode of said energy source assembly electrically contacts said barrel.

43. A lighting device of claim 42, wherein said barrel includes an inner feature that generally corresponds to said outer feature of said energy source assembly, wherein said second electrode of said energy source assembly frictionally engages to said inner feature.

44. A lighting device of claim 42 further including a reflector that reflects light generated by said light source, said reflector having a first open end, a second end, and a parabolic profile extending between said first open end and said second end, wherein the focal point of said parabolic profile is located outside said parabolic profile.

45. A lighting device of claim 42, wherein said housing of said energy source assembly includes receptacles arranged to hold said plurality of energy sources in a side-by-side arrangement.

46. A lighting device of claim 42, wherein said electrical circuit arrangement of said energy source assembly is a series circuit.

47. A lighting device of claim 42, wherein said electrical circuit arrangement of said energy source assembly is a parallel circuit.

48. A lighting device of claim 42, wherein said plurality of energy sources is a plurality of batteries.

49. A lighting device comprising:

a source of energy;

a light source coupled to said source of energy;

a temperature responsive resistor disposed to detect the temperature of said light source;

a current modulating circuit coupled to said temperature responsive resistor, wherein said current modulating circuit delivers a thermally compensated pulsed current to said light source.

50. A lighting device of claim 49, wherein the pulsed current is thermally compensated by adjusting the duty cycle of the pulsed current based on the temperature of said light source detected by said temperature responsive resistor.

51. A lighting device of claim 50, wherein the duty cycle of the pulsed current reduces if the temperature of said light source increases.

52. A lighting device of claim 50, wherein the duty cycle of the pulsed current increases if the temperature of the light source decreases.

53. A lighting device of claim 50, wherein said light source is an LED.

54. A lighting device of claim 49, wherein said temperature responsive resistor is a thermistor.

55. A lighting device of claim 49 further including a diode electrically coupled to said current modulating circuit, wherein said diode prevents current flow should said source of energy be reversely installed.