Lamp comprised of a composite reflector and aspheric lenses

• US 6,244,731 B1
• Filed: 04/30/1999
• Issued: 06/12/2001
• Est. Priority Date: 05/01/1998
• Status: Active Grant

• Current Assignee: Stanley Electric Company Limited
• Original Assignee: Stanley Electric Company Limited
• Inventors: Koiko, Teruo, Kawaguchi, Yoshifumi, Futami, Takashi
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): TON, ANABEL
• Application Number:
  US09/303,476
• Time in Patent Office: 774 Days
• Field of Search: 362/297, 362/346, 362/518, 362/516, 362/348, 362/309, 362/308, 362/328, 362/268, 362/351, 362/307, 362/293, 362/343
• US Class Current: 362/297
• CPC Class Codes: F21S 41/265 Composite lenses; Lenses with a patch-like shape
• CPC Class Codes: F21S 41/28 Cover glass
• CPC Class Codes: F21S 41/336 with discontinuity at the junction between adjacent areas

Abstract

A lamp is composed of a light source, a composite reflector consisting of a plurality of reflecting surface units, and aspheric lenses provided to correspond to the individual reflecting surface units. The composite reflector includes a first and a second reflecting surface units. Each of the first reflecting surface units is formed of a reflecting surface configuration obtained by cutting, radially around a center axis of the light source, a portion from a spheroid having a first focal point located on the center axis and adjacent the light source and a second focal point located on a line passing through the first focal point and tilted appropriately from the center axis such that the cut portion spans a range of 15° to 90° around the center axis. Each of the second reflecting surface units is composed of a second reflecting surface configuration obtained by similarly cutting a portion from a spheroid having a second focal point located external to the first reflecting surface configuration. The first and second reflecting surface configurations are defined in non-overlapping relation with each other to form effective reflecting surfaces. Of the reflecting surface units, the identical ones are combined concentrically to compose the composite reflector. The aspheric lenses are provided to correspond to the respective second focal points of the reflecting surface units of the composite reflector and converge reflected light beams from the respective reflecting surface units.

Claims

1. A lamp comprising:

a light source positioned on a central axis of the lamp;

a composite reflector including a plurality of first reflecting units and a plurality of second reflecting units,

each of the first reflecting units being a portion of the inner surface of one of a plurality of first ellipsoidal bodies, the first ellipsoidal bodies having;

respective first focal points located on the center axis adjacent to the light source; and

respective second focal points located on a line that lies at a first angle relative to the center axis, and disposed in spaced relationship on a plane normal to the center axis and on a circle with its center on the center axis;

each off the first reflecting units being bounded by the intersections of the respective first ellipsoidal bodies with first and second planes extending radially from the center axis and separated from each other by a second angle;

the spacing of second focal points on the circle being such that the first reflecting units do not overlap;

each of the second reflecting units being a portion of the inner surface of one of a plurality of second ellipsoidal bodies, the second ellipsoidal bodies having;

respective first focal points located on the center axis adjacent to the light source; and

respective second focal points located on a line that lies at a third angle relative to the center axis, and disposed in spaced relationship on a plane normal to the center axis and on a circle with its center on the center axis;

each of the second reflecting units being bounded by the intersections of the respective second ellipsoidal bodies with first and second planes extending radially from the center axis and separated from each other by a fourth angle;

the spacing of second focal points on the circle being such that the second reflecting units do not overlap;

the distances between the first reflecting units and the respective second focal points being unequal to the distances between the second reflecting units and the respective second focal points; and

an aspheric lens respectively associated with each of the first and second reflecting units, the respective second focal point of each of the reflecting units being positioned on the optical axis of the associated aspheric lens to converge a reflected light beam from the respective reflecting unit.

2. The lamp according to claim 1, wherein all the aspheric lenses are formed integrally with a lens holder portion and said lens holder portion is formed transparent or opaque.

3. The lamp according to claim 1, wherein each of said aspheric lenses is formed of any one of a convex lens, a Fresnel lens, and a combination of the convex lens and the Fresnel lens.

4. The lamp according to claim 1, wherein each of said aspheric lenses is partly composed of a cylindrical lens.

5. The lamp according to claim 1, wherein at least one of the surface of said shade for forming a light distribution pattern viewed through said aspheric lens and said lens holder portion is in a color other than the color of the aspheric lens.

6. The lamp according to claim 1, wherein said light source is provided with a diffusion filter or color filter in the form of a cap.

7. A lamp as described in claim 1, in which the composite reflector further includes a plurality of third reflecting units,

each of the third reflecting units being a portion of the inner surface of one of a plurality of third ellipsoidal bodies, the third ellipsoidal bodies having:

respective first focal points located on the center axis adjacent to the light source; and

respective second focal points located on a line that lies at a fifth angle relative to the center axis, and disposed in spaced relationship on a plane normal to the center axis and on a circle with its center on the center axis;

each of the third reflecting units being bounded by the intersections of the respective third ellipsoidal bodies with first and second planes extending radially from the center axis and separated from each other by a sixth angle;

the spacing of second focal points on the circle being such that the second reflecting units do not overlap;

the distances between the third reflecting units and the respective second focal points being unequal to the distances between the first reflecting units and the respective second focal points and also unequal to the distances between the second reflecting units and the respective second focal points.

8. A lamp as described in claim 7, in which the first, second and third ellipsoidal bodies are prolate spheroids.

9. A lamp as described in claim 8, further including a plurality of shades for forming a light distribution pattern, each of the shades being disposed respectively at a near-focal point of one of the aspheric lens.

10. A lamp as described in claim 8, further including:

a central reflector formed of a portion cut from a further ellipsoidal body having a first focal point adjacent to the light source and having a long axis thereof coincident with the center axis; and

a further aspheric lens located at the second focal point of the central reflector.

11. A lamp as described in claim 10, further including a shade for forming a light distribution pattern disposed at a near-focal point of the further aspheric lenses.

12. A lamp as described in claim 7, in which:

the first, second and third ellipsoidal bodies are elliptical free-form bodies; and

the second focal points all extend in the horizontal direction when the lamp is mounted in its operative position.

13. A lamp as described in claim 12, further including a plurality of shades which form light distribution patterns, the shades being disposed respectively at near-focal points of each of the aspheric lenses, each of the shades being curved symmetrically along the horizontal extent thereof toward the respective aspheric lens.

14. A lamp as described in claim 12, further including:

a central reflector formed of a portion cut from a further elliptical body, the central reflector having a first focal point adjacent to the light source, a long axis coinciding with the center axis and a second focal point which extends horizontally when the lamp is mounted in its operative position; and

a further aspheric lens located at the second focal point of the central reflector.

15. A lamp as described in claim 14, further including a shade which forms a light distribution pattern, the shade being disposed at near-focal point of the further aspheric lenses, the shade being curved symmetrically along the horizontal extent thereof toward the further aspheric lens.

16. A lamp as described in claim 7, in which the second fourth and sixth angles are in the range of about 15 to about 90 degrees.

17. A lamp as described in claim 16, in which the first, second and third ellipsoidal bodies are prolate spheroids.

18. A lamp as described in claim 17, further including a plurality of shades for forming light distribution patterns, each of the shades being disposed respectively at a near-focal point of one of the aspheric lenses.

19. A lamp as described in claim 17, further including:

a central reflector formed of a portion cut from a further ellipsoidal body having a first focal point adjacent to the light source and having a long axis thereof coincident with the center axis; and

a further aspheric lens located at the second focal point of the central reflector.

20. A lamp as described in claim 19, further including a shade for forming a light distribution pattern disposed at a near-focal point of the further aspheric lens.

21. A lamp as described in claim 16, in which the first, second and third ellipsoidal bodies are elliptical free-form bodies.

22. A lamp as described in claim 21, further including a plurality of shades which form light distribution patterns, the shades being disposed respectively at near-focal points of each of the aspheric lenses, each of the shades being curved symmetrically along the horizontal extent thereof toward the respective aspheric lens.

23. A lamp as described in claim 21, further including:

a central reflector formed of a portion cut from a further elliptical body, the central reflector having a first focal point adjacent to the light source, a long axis coinciding with the center axis and a second focal point which extends horizontally when the lamp is mounted in its operative position; and

a further aspheric lens located at the second focal point of the central reflector.

24. A lamp as described in claim 23, further including a shade which forms a light distribution pattern, the shade being disposed at a near-focal point of the further aspheric lens, the shade being curved symmetrically along the horizontal extent thereof toward the further aspheric lens.

25. A lamp as described in claim 1, in which the first and second ellipsoidal bodies are prolate spheroids.

26. A lamp as described in claim 25, further including a plurality of shades for forming a light distribution pattern, each of the shades being disposed respectively at a near-focal point of one of the aspheric lens.

27. A lamp as described in claim 25, further including:

a central reflector formed of a portion cut from a further ellipsoidal body having a first focal point adjacent to the light source and having a long axis thereof coincident with the center axis; and

a further aspheric lens located at the second focal point of the central reflector.

28. A lamp as described in claim 27, further including a shade for forming a light distribution pattern disposed at a near-focal point of the further aspheric lens.

29. A lamp as described in claim 1, in which:

the first and second ellipsoidal bodies are elliptical free-form bodies; and

the second focal points all extend in the horizontal direction when the lamp is mounted in its operative position.

30. A lamp as described in claim 29, further including a plurality of shades which form light distribution patterns, the shades being disposed respectively at near-focal points of each of the aspheric lenses, each of the shades being curved symmetrically along the horizontal extent thereof toward the respective aspheric lens.

31. A lamp as described in claim 29, further including:

a central reflector formed of a portion cut from a further elliptical body, the central reflector having a first focal point adjacent to the light source, a long axis coinciding with the center axis and a second focal point which extends horizontally when the lamp is mounted in its operative position; and

a further aspheric lens located at the second focal point of the central reflector.

32. A lamp as described in claim 31, further including a shade which forms a light distribution pattern, the shade being disposed at a near-focal point of the further aspheric lens, the shade being curved symmetrically along the horizontal extent thereof toward the further aspheric lens.

33. A lamp as described in claim 1, in which the second and fourth angles are in the range of about 15 to about 90 degrees.

34. A lamp as described in claim 33, in which the first and second ellipsoidal bodies are prolate spheroids.

35. A lamp as described in claim 34, further including a plurality of shades for forming light distribution patterns, each of the shades being disposed respectively at a near-focal point of one of the aspheric lens.

36. A lamp as described in claim 34, further including:

a central reflector formed of a portion cut from a further ellipsoidal body having a first focal point adjacent to the light source and having a long axis thereof coincident with the center axis; and

a further aspheric lens located at the second focal point of the central reflector.

37. A lamp as described in claim 36, further including a shade for forming a light distribution pattern disposed at a near-focal point of the further aspheric lens.

38. A lamp as described in claim 33, in which:

the first and second ellipsoidal bodies are elliptical free-form bodies; and

the second focal points all extend in the horizontal direction when the lamp is mounted in its operative position.

39. A lamp as described in claim 38, further including a plurality of shades which form light distribution patterns, the shades being disposed respectively at near-focal points of each of the aspheric lenses, each of the shades being curved symmetrically along the horizontal extent thereof toward the respective aspheric lens.

40. A lamp as described in claim 38, further including:

a central reflector formed of a portion cut from a further elliptical body, the central reflector having a first focal point adjacent to the light source, a long axis coinciding with the center axis and a second focal point which extends horizontally when the lamp is mounted in its operative position; and

a further aspheric lens located at the second focal point of the central reflector.

41. A lamp as described in claim 40, further including a shade which forms a light distribution pattern, the shade being disposed at a near-focal point of the further aspheric lens, the shade being curved symmetrically along the horizontal extent thereof toward the further aspheric lens.