Flashlight producing uniform high brightness

• US 6,746,124 B2
• Filed: 02/05/2002
• Issued: 06/08/2004
• Est. Priority Date: 02/06/2001
• Status: Expired due to Term

• Current Assignee: Optics 1, Inc. (Safran SA)
• Original Assignee: Optics 1, Inc. (Safran SA)
• Inventors: Fischer, Robert E., Kappel, David, Moeller, Greg
• Primary Examiner(s): Gray, David
• Assistant Examiner(s): Koval, Melissa J
• Application Number:
  US10/068,366
• Publication Number:
  US 20020118344A1
• Time in Patent Office: 854 Days
• Field of Search: 353/43, 353/20, 353/30, 353/34, 353/37, 353/97, 353/121, 353/122, 353/102, 353/119, 362/187, 362/188, 362/157, 362/347
• US Class Current: 353/43
• CPC Class Codes: F21L 4/027 the light sources being a LED
• CPC Class Codes: F21V 11/08 using diaphragms containing one or more apertures
• CPC Class Codes: F21V 14/065 in portable lighting devices
• CPC Class Codes: F21V 2200/13 the light being emitted at the end of the guide
• CPC Class Codes: F21Y 2101/00 Point-like light sources
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G03B 21/001 Slide projectors
• CPC Class Codes: G03B 21/14 Details
• CPC Class Codes: G03B 21/2066 Reflectors in illumination beam in projection beam G03B21/28
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light

Abstract

A flashlight that generates a flashlight beam to illuminate an object at a selectable distance from the flashlight by imaging a uniformly bright pattern of light onto the object. A light modifying component can be used to manipulate the pattern of light into particular shapes and images. In one embodiment, light from a light source is coupled into a light pipe. The light is homogenized as it travels along the light pipe. The light exits the light pipe with a more uniform intensity than when it entered. The light exiting the light pipe is then reimaged by an imaging lens onto an object. Yet in other embodiments, one or more lens arrays having two or more lenlets are used to homogenize the light originating from the light source.

Claims

1. A flashlight for uniformly illuminating an object to be viewed, comprising:

a light source;

a light homogenizer arranged to receive light from the light source at an input face and adapted to output uniformized light at an output face, wherein the light homogenizer includes i) a light pipe or ii) one or more lens arrays; and

an imaging lens arranged adjacent the output face and at an output end of the flashlight to create a flashlight beam that forms an image of the output face at a distance from the output end of the flashlight so as to uniformly illuminate the object when the object is located at said distance.

2. The flashlight of claim 1, further comprising:

a reflector adapted to reflect light from the light source towards the input end of the light homogenizer.

3. The flashlight of claim 2, wherein the reflector is an elliptical reflector.

4. The flashlight of claim 1, wherein the light source is one selected from the group of light sources comprising:

a conventional flashlight bulb, a light emitting diode, a laser, and an arc lamp.

5. The flashlight of claim 1, further including one or more batteries connected to the light source to power the light source.

6. The flashlight of claim 5, further including a hand-held housing that houses the light source, the light homogenizer, the imaging lens and the one or more batteries.

7. The flashlight of claim 1, wherein imaging lens is adjustable relative to the output face to adjust the distance at which the uniform illumination is formed.

8. The flashlight of claim 1, further comprising

a light modifying component arranged at the output face of the light homogenizer.

9. The flashlight of claim 8, wherein the light modifying component is a mask.

10. The flashlight of claim 8, wherein the light modifying component is a film.

11. The flashlight of claim 1, wherein the input face has a smaller area than the output face.

12. The flashlight of claim 1, wherein the input face and the output face have substantially the same area.

13. The flashlight of claim 1, further comprising a diffuser.

14. The flashlight of claim 1, wherein the light homogenizer is a hollow light pipe.

15. The flashlight of claim 1, wherein the light homogenizer is a solid light pipe.

16. The flashlight of claim 15, wherein the solid light pipe is a circular rod of glass.

17. The flashlight of claim 1, wherein the light homogenizer is a lens array that includes lenslets.

18. The flashlight of claim 1, wherein the light homogenizer comprises two lens arrays each having lenslets.

19. A method of forming a flashlight beam to uniformly illuminate an object at a selectable distance from the flashlight comprising:

generating light from a light source;

homogenizing the light by passing the light through a light homogenizer that includes i) a light tunnel or ii) one or more lens arrays;

receiving the homogenized light from an output face of the light homogenizer with an imaging lens; and

using the imaging lens, focusing the received light as a flashlight beam to form a uniform image at the object.

20. The method of claim 19, including adjusting the imaging lens to adjust the selectable distance from the flashlight at which the uniform image is formed.

21. The method of claim 19, further comprising powering the light source with a battery.

22. The method of claim 19, wherein the uniform image has a boundary, and further comprising shaping the boundary by modifying the homogenized light exiting the homogenizer.

23. The method of claim 19, further comprising altering the light image exiting the output face to produce an image.

24. A flashlight that creates uniform illumination at a selectable distance from the flashlight, comprising:

a light source connected to one or more batteries for powering the light source;

a light homogenizer optically coupled to the light source and adapted to uniformize light from the light source and output uniformized light at an output face, wherein the light homogenizer is one selected from the group of light homogenizers comprising;

(a) a light pipe, (b) a single lens array having two or more lenslets, and (c) a double lens array wherein each lens array in the double lens array includes two or more lenslets;

an imaging lens adapted to receive the uniformized light and create a flashlight beam that forms an image of the output face at the selectable distance; and

a hand-held housing that houses the light source, the one or more batteries, the light homogenizer, and the imaging lens.

25. The flashlight of claim 24, wherein the imaging lens is adjustable to adjust the flashlight beam in order to change the selectable distance.