LED lamp including refractive lens element

• US 5,174,649 A
• Filed: 07/17/1991
• Issued: 12/29/1992
• Est. Priority Date: 07/17/1991
• Status: Expired due to Term

• Current Assignee: Precision Solar Controls Incorporated (New Enterprise Stone & LIME Company Incorporated)
• Original Assignee: Precision Solar Controls Incorporated (New Enterprise Stone & LIME Company Incorporated)
• Inventors: Alston, Kevin G.
• Primary Examiner(s): Cole, Richard R.
• Application Number:
  US07/731,621
• Time in Patent Office: 531 Days
• Field of Search: 362/244, 362/236, 362/237, 362/268, 362/308, 362/309, 362/331, 362/332, 362/335, 362/800, 359/622, 359/624, 359/794
• US Class Current: 362/244
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21W 2111/02 for roads, paths or the like
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: Y10S 362/80 Light emitting diode

Abstract

A lamp includes one or more LED'"'"'s which illuminate respective portions of a refractive lens element whose incident surface preferably includes portions of hyperboloids which translate the LEDs'"'"' emitted rays into substantially parallel beams within the lens element. The lens element'"'"'s exit surface is preferably an array of facets configured to provide a desired beam spread pattern, allowing precise tailoring of the resultant output beam pattern. The plurality of facets also allows a larger area on the lamp to appear to viewers to be uniformly illuminated, thus providing full target size definition at a decreased cost and with reduced power consumption.

Claims

1. An apparatus for emanating electromagnetic radiation as a desired output beam, the apparatus comprising:

a) at least one emitting device for producing an emitted beam of electromagnetic radiation; and

b) a lens element including, for each emitting device;

1) an entrance surface shaped to refract the emitted beam into an intra-lens beam; and

2) an exit surface including at least two facets shaped to refract the intra-lens into the desired output beam;

wherein the emitting device is located at a focus of the lens entrance surface.

2. The apparatus of claim 1, wherein at least one of the emitting devices is a light emitting diode (LED).

3. The apparatus of claim 1, wherein the entrance surface includes a portion of a hyperboloid having a focus of which is located one of the emitting devices.

4. The apparatus of claim 1, wherein the entrance surface is shaped to refract the emitted beam into an intra-lens beam substantially all of whose electromagnetic energy travels in an essentially parallel direction.

5. The apparatus of claim 1, wherein at least one facet of the exit surface is convex.

6. The apparatus of claim 1, wherein at least one facet of the exit surface is concave.

7. The apparatus of claim 1, wherein at least one facet of the exit surface is formed with an imaginary center of curvature which is located on an imaginary center line passing midway between opposite edges of the facet and perpendicular to a line connecting the opposite edges, so that the desired output beam is substantially on-axis to the direction of the intra-lens beam.

8. The apparatus of claim 1, wherein at least one facet of the exit surface is formed with an imaginary center of curvature that is located off an imaginary center line passing midway between a first set of opposite edges of the facet and perpendicular to a line connecting the opposite edges, so that the desired output lens is skewed in a first direction with respect to the axis of the intra-lens beam.

9. The apparatus of claim 8, wherein the imaginary center of curvature is located off the imaginary center line passing midway between a second set of opposite edges of the facet and perpendicular to a line connecting the second set of opposite edges, so that the desired output beam is skewed in a second direction with respect to the axis of the intra-lens beam.

10. The apparatus of claim 1, wherein the exit surface includes:

a first facet having a first radius of curvature defining its outer surface so that it emits an output beam subtending a first angle in a first direction and a second angle in a second direction, the first facet emanating electromagnetic energy having a first beam spread; and

a second facet having a second radius of curvature defining its outer surface so that it emits an output beam subtending a third angle in a third direction and a fourth angle in a fourth direction, the second facet emanating electromagnetic energy having a second beam spread;

wherein at least one of the first and second angles is not the same as a corresponding one of the third and fourth angles, so that the first beam spread is different in angularity, or intensity, or angularly and intensity, than the second beam spread.

11. The apparatus of claim 1, further comprising a housing which includes:

a baffle arrangement for each emitting device, oriented to substantially surround sides of the emitting device to minimize the amount of electromagnetic radiation which falls upon the emitting device.

12. The apparatus of claim 1, further comprising:

a) a board on which the at least one emitting device is situated; and

b) a housing, including;

1) a baffle arrangement oriented around each emitting device and adjacent the board, to substantially surround sides of the emitting device to reduce the amount of electromagnetic radiation which falls upon the emitting device;

2) a first set of attachment structures for attaching the housing to the board on which the emitting devices are attached; and

3) a second attachment structure for matingly engaging a corresponding lens attachment structure on the lens element, so that the lens element may be fixed to the housing.

13. The apparatus of claim 1, wherein:

a) the at least one emitting device includes LED'"'"'s, the emitted beam of the LED'"'"'s having respective beam spread and beam axes; and

b) the lens element is constructed and arranged so that;

1) the lens element entrance surface includes a number of hyperboloidal surfaces corresponding to the number of LED'"'"'s, the hyperboloidal surfaces being centered on respective beam axes of respective LED'"'"'s and having hyperboloidal surface edges generally corresponding to the respective beam spreads of the respective LED'"'"'s, the hyperboloidal surfaces receiving respective emitted beams;

2) each hyperboloidal surface is shaped to refract the emitted beam into an intra-lens beam whose components travel substantially parallel paths; and

3) the facets are grouped into subsets of facets, the subsets arranged to receive intra-lens beams from respective ones of the hyperboloidal surfaces.

14. The apparatus of claim 13, wherein there are exactly four LED'"'"'s, four hyperboloidal surfaces, and four rows and twelve columns of facets including four subsets of twelve facets.

15. The apparatus of claim 14, wherein each facet has an outer surface which subtends a horizontal angle of about 36°

14'"'"' and a vertical angle of about 12°

2'"'"', the resultant desired output beam subtending a projected angle of about 18°

horizontally and 6°

vertically.

16. The apparatus of claim wherein the emitting device includes a device for emitting electromagnetic energy lying substantially within the light spectrum visible to humans.

17. A lamp, comprising:

a) at least one LED for producing an emitted light beam, the emitted beams of the LED'"'"'s having respective beam spreads and beam axes;

b) a board on which the at least one LED is situated;

c) a lens element, including;

1) an entrance surface which includes a number of hyperboloidal surfaces corresponding to the number of LED'"'"'s, the hyperboloidal surfaces being centered on respective beam axes of respective LED'"'"'s and having hyperboloidal surface edges generally corresponding to the respective beam widths of the respective LED'"'"'s, the hyperboloidal surfaces receiving respective emitted beams, each hyperboloidal surface being shaped to refract the emitted beam into an intralens lens light beam whose components travel substantially parallel paths; and

2) an exit surface including at least one facet shaped to refract the intra-lens light beam into a desired output beam, the facets being grouped into subsets of facets, the subsets arranged to refract intra-lens light from respective ones of the hyperboloidal surfaces into a desired output beam; and

d) a housing, including;

1) a baffle arrangement oriented around each LED and adjacent the board, to substantially surround sides of the LED to reduce the amount of light which falls upon the LED;

2) a first set of attachment structures for attaching the housing to the board on which the LED'"'"'s are attached; and

3) a second attachment structure for matingly engaging a corresponding lens attachment structure on a lens element, so that the lens element may be fixed to the housing.

18. An apparatus for emanating electromagnetic radiation as a desired output beams, the apparatus comprising:

a) at least one emitting device for producing an emitted beam of electromagnetic radiation; and

b) a lens element including, for each emitting device;

1) an entrance surface shaped to refract the emitted beam into an intra-lens beam; and

2) an exit surface including at least one facet shaped to refract the intra-lens beam into the desired output beam;

wherein;

A) the emitting device is located at a focus of the lens entrance surface; and

B) wherein at least one facet of the exit surface is formed with an imaginary center of curvature that is located off an imaginary center line passing midway between a first set of opposite edges of the facet and perpendicular to a line connecting the opposite edges, so that the desired output beam is skewed in a first direction with respect to the axis of the intra-lens beam.

19. The apparatus of claim 18, wherein the imaginary center of curvature is located off the imaginary center line passing midway between a second set of opposite edges of the facet and perpendicular to a line connecting the second set of opposite edges, so that the desired output beam is skewed in a second direction with respect to the axis of the intra-lens beam.

20. An apparatus for emanating electromagnetic radiation as a desired output beam, the apparatus comprising:

a) at least one emitting device for producing an emitted beam of electromagnetic radiation; and

b) a lens element including, for each emitting device;

1) an entrance surface shaped to refract the emitted beam into an intra-lens beam; and

2) an exit surface including at least one facet shaped to refract the intra-lens beam into the desired output beam;

wherein;

A) the emitting device is located at a focus of the lens entrance surface;

B) the exit surface includes;

1) a first facet having a first radius of curvature defining its outer surface so that it emits an output beam subtending a first angle in a first direction and a second angle in a second direction, the first facet emanating electromagnetic energy having a first beam spread; and

2) a second facet having a second radius of curvature defining its outer surface so that it emits an output beam subtending a third angle in a third direction and a fourth angle in a fourth direction, the second facet emanating electromagnetic energy having a second beam spread;

C) at least one of the first and second angles is not the same as a corresponding one of the third and fourth angles, so that the first beam spread is different in angularity, or intensity, or angularity and intensity, than the second beam spread.

21. An apparatus for emanating electromagnetic radiation as a desired output beam, the apparatus comprising:

a) at least one emitting device for producing an emitted beam of electromagnetic radiation;

b) a lens element including, for each emitting device;

1) an entrance surface shaped to refract the emitted beam into an intra-lens beam; and

2) an exit surface including at least one facet shaped to refract the intra-lens beam into the desired output beam;

wherein the emitting device is located at a focus of the lens entrance surface

c) a board on which the at lest one emitting device is situated; and

d) a housing, including;

1) a baffle arrangement oriented around each emitting device and adjacent the board, to substantially surround sides of the emitting device to reduce the amount of electromagnetic radiation which falls upon the emitting device;

2) a first set of attachment structures for attaching the housing to the board on which the emitting devices are attached; and

3) a second attachment structure for matingly engaging a corresponding lens attachment structure on the lens element, so that the lens element may be fixed to the housing.

22. An apparatus for emanating electromagnetic radiation as a desired output beam, the apparatus comprising:

a) at least one emitting device for producing an emitted beam of electromagnetic radiation; and

b) a lens element including, for each emitting device;

1) an entrance surface adapted to refract the emitted beam into an intra-lens beam; and

2) an exit surface including at least one facet shaped to refract the intra-lens beam into the desired output beam;

wherein;

A) the emitting device is located at a focus of the lens entrance surface;

B) the at least one emitting device includes LED'"'"'s, the emitted beams of the LED'"'"'s having respective beam spreads and beam axes; and

C) the lens element is constructed and arranged so that;

1) the lens element entrance surface includes a number of hyperboloidal surfaces corresponding to the number of LED'"'"'s, the hyperboloidal surfaces being centered on respective beam axes of respective LED'"'"'s and having hyperboloidal surface edges generally corresponding to the respective beam spreads of the respective LED'"'"'s, the hyperboloidal surfaces receiving respective emitted beams;

2) each hyperboloidal surface is shaped to refract the emitted beam into an intra-lens beam whose components travel substantially parallel paths; and

3) the facets are grouped into subsets of facts, the subsets arranged to receive intra-lens beams from respective ones of the hyperboloidal surfaces.

23. The apparatus of claim 22, wherein there are exactly four LED'"'"'s, four hyperboloidal surfaces, and four rows and twelve columns of facets including four subsets of twelve facets.

24. The apparatus of claim 23, wherein each facet has an outer surface which subtends a horizontal angle of about 36°

42'"'"'and a vertical angle of about 12°

2'"'"', the resultant desired output beam subtending a projected angle of about 18°

horizontally and 6°

vertically.

25. An apparatus for emanating electromagnetic radiation as a desired output beam, the apparatus comprising:

a) at least one emitting device for producing an emitted beam of electromagnetic radiation, the at least one emitting device having respective characteristic beam spreads and beam axes, the beam spreads defining generally cone-shaped regions within which the electromagnetic radiation is concentrated and outside of which electromagnetic radiation is substantially reduced or eliminated; and

b) a least element including, for each emitting device;

1) an entrance surface shaped to refract the emitted beam into an intra-lens beam, the lens element positioned with respect to the emitting device so that edges of the entrance surface substantially correspond to edges of the characteristic beam spread; and

2) an exit surface including at least one facet shaped to refract the intra-lens beam into the desired output beam;

wherein the emitting device is located at a focus of the lens entrance surface,

26. The apparatus of claim 25, wherein at least one of the emitting devices is a light emitting diode (LED).

27. The apparatus of claim 25, wherein the entrance surface includes a portion of a hyperboloid having a focus at which is located one of the emitting devices.

28. The apparatus of claim 25, wherein the entrance surface is shaped to refract the emitted beam into an intra-lens beam substantially all of whose electromagnetic energy travels in an essentially parallel direction.

29. The apparatus of claim 25, wherein the facet of the exit surface is convex.

30. The apparatus of claim 25, wherein the facet of the exit surface is concave.

31. The apparatus of claim 25, wherein the facet of the exit surface is formed with an imaginary center of curvature which is located on an imaginary center line passing midway between opposite edges of the facet and perpendicular to a line connecting the opposite edges, so that the desired output beam is substantially on-axis to the direction of the intra-lens beam.

32. The apparatus of claim 25, wherein at least one facet of the exit surface is formed with an imaginary center of curvature that is located off an imaginary center line passing midway between a first set of opposite edges of the facet and perpendicular to a line connecting the opposite edges, so that the desired output beam is skewed in a first direction with respect to the axis of the intra-lens beam.

33. The apparatus of claim 32, wherein the imaginary center of curvature is located off the imaginary center line passing midway between a second set of opposite edges of the facet and perpendicular to a line connecting the second set of opposite edges, so that the desired output beam is skewed in a second direction with respect to the axis of the intra-lens beam.

34. The apparatus of claim 25, wherein the exit surface includes:

a first facet having a first radius of curvature defining its outer surface so that it emits an output beam subtending a first angle in a first direction and a second angle in a second direction, the first facet emanating electromagnetic energy having a first beam spread; and

a second facet having a second radius of curvature defining its outer surface so that it emits an output beam subtending a third angle in a third direction and a fourth angle in a fourth direction, the second facet emanating electromagnetic energy having a second beam spread;

wherein at least one of the first and second angles is not the same as a corresponding one of the third and fourth angles, so that the first beam spread is different in angularity, or intensity, or angularity and intensity, than the second beam spread.

35. The apparatus of claim 25, further comprising a housing which includes:

a baffle arrangement for each emitting device, oriented to substantially surround sides of the emitting device to minimize the amount of electromagnetic radiation which falls upon the emitting device.

36. The apparatus of claim 25, further comprising:

a) a board on which the at least one emitting device is situated; and

b) a housing, including;

1) a baffle arrangement oriented around each emitting device and adjacent the board, to substantially surround sides of the emitting device to reduce the amount of electromagnetic radiation which falls upon the emitting device;

2) a first set of attachment structures for attaching the housing to the board on which the emitting devices are attached; and

3) a second attachment structure for matingly engaging a corresponding least attachment structure on the lens element, so that the lens element may be fixed to the housing.

37. The apparatus of claim 25, wherein:

a) the at least one emitting device includes LED'"'"'s, the emitted beams of the LED'"'"'s having respective beam spreads and beam axes; and

b) the lens element is constructed and arranged so that;

1) the lens element entrance surface includes a number of hyperboloidal surfaces corresponding to the number of LED'"'"'s, the hyperboloidal surfaces being centered on respective beam axes of respective LED'"'"'s and having hyperboloidal surface edges generally corresponding to the respective beam spreads of the respective LED'"'"'s, the hyperboloidal surfaces receiving respective emitted beams;

2) each hyperboloidal surface is shaped to refract the emitted beam into an intra-lens beam whose components travel substantially parallel paths; and

3) the facets are grouped into subsets of facets, the subsets arranged to receive intra-lens beams from respective ones of the hyperboloidal surfaces.

38. The apparatus of claim 37, wherein there are exactly four LED'"'"'s, four hyperboloidal surfaces, and four rows and twelve columns of facets including four subsets of twelve facets.

39. The apparats of claim 38, wherein each facet has an outer surface which subtends a horizontal angle of about 36°

42'"'"' and a vertical angle of about 12°

2'"'"', the resultant desired output beam subtending a projected angle of about 18°

horizontally and 6°

vertically.

40. The apparatus of claim 25, wherein the emitting device includes a device for emitting electromagnetic energy lying substantially within the light spectrum visible to humans.