Led-based flashlight

• US 7,077,525 B2
• Filed: 03/05/2004
• Issued: 07/18/2006
• 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., Prince, Simon, Moeller, Greg
• Primary Examiner(s): KOVAL, MELISSA J
• Application Number:
  US10/794,073
• Publication Number:
  US 20050007767A1
• Time in Patent Office: 865 Days
• Field of Search: 353/43, 353/20, 353/30, 353/34, 353/37, 353/97, 353/121, 353/122, 353/102, 353/119, 353/31, 353/53, 353/98, 353/85, 353/94, 353/101, 362/187, 362/188, 362/157, 362/347, 362/184, 362/202
• US Class Current: 353/43
• 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 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: F21V 2200/17 characterised by the admission of light into the guide
• CPC Class Codes: F21V 5/04 of lens shape
• CPC Class Codes: F21V 9/40 with provision for controlling spectral properties, e.g. colour, or intensity
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: G02B 27/0961 Lens arrays lens arrays per se G02B3/0006
• CPC Class Codes: G02B 27/0994 Fibers, light pipes optical fibers per se G02B6/02
• CPC Class Codes: G03B 21/2013 Plural light sources
• CPC Class Codes: G03B 21/2033 LED or laser light sources
• CPC Class Codes: G03B 21/208 Homogenising, shaping of the illumination light

Abstract

A flashlight that utilizes an array of one or more light-emitting diodes (LEDs) as a light source, and a light pipe as a light homogenizer to generate a light beam capable of forming a uniformized light distribution at a given distance from the flashlight is disclosed. The LEDs may be all the same color, or some or all may be different colors. A switch, coupled to switching electronics coupled to the LED array, is used to change the state of the LED array to create a variety of different types of light beams, each of which provides relatively uniform and bright illumination at a given distance from the flashlight, wherein the given distance is selectable by adjusting an adjustable imaging lens.

Claims

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

a light pipe having an input face, an output face, and a plurality of sides;

an array of one or more light-emitting diodes (LEDs) optically

coupled to the input face of the light pipe;

an imaging lens arranged adjacent the light pipe output face and at an output end of the flashlight; and

one or more batteries operably coupled to the one or more LEDs and arranged adjacent one or more of the sides.

2. The flashlight of claim 1, wherein the imaging lens is adjustable to form an image of the output face of the light pipe at a select distance from the flashlight output end.

3. The flashlight of claim 1, wherein the LED array includes at least two LEDs having a different color.

4. The flashlight of claim 3, wherein the LED array includes at least one red, one green and one blue LED.

5. The flashlight of claim 1, wherein the input face of the light pipe has one or more cavities formed therein and sized to respectively accommodate the one or more LEDs in the LED array.

6. The flashlight of claim 1, wherein the one or more LEDs are dies.

7. The flashlight of claim 1, wherein the one or more LEDs are packaged.

8. The flashlight of claim 1, further including:

an electronic switching circuit electrically coupled to the LED array; and

a switch operably coupled to the switching circuit to activate the switching circuit in order to change the state of the LED array.

9. The flashlight of claim 1, wherein the light pipe constitutes a light pipe assembly comprising:

a first light pipe having a first input end and a first output end; and

one or more secondary light pipes coupled to the main light pipe, with each of the one or more secondary light pipes having a second input end and a second output end; and

wherein the one or more secondary light pipes are coupled to or formed integral with the main light pipe so each second output end is interfaced with the first input end of the main light pipe, and wherein the one or more second input ends constitute said input face.

10. The flashlight of claim 9, wherein:

the first input face of the main light pipe has a first area greater than that of the first output face; and

the second input end of the one or more secondary light pipes has a second area less than that of the second output end.

11. The flashlight of claim 1, further including one or more second LEDs optically coupled to one or more of the plurality of sides of the light pipe.

12. The flashlight of claim 11, wherein one or more of the second LEDs are embedded in at least one of the plurality of sides of the light pipe.

13. A method of forming a flashlight beam to illuminate an object, comprising:

generating light from one or more light-emitting diodes (LEDs);

coupling the light into the a light pipe and outputting uniformized light at an output face of the light pipe;

collecting the outputted light from the light pipe with an imaging lens and directing the outputted light as a flashlight beam; and

bringing the flashlight beam into focus onto the object so as to uniformly illuminate the object by adiusting the imaging lens so as to select a distance at which the flashlight beam forms a uniform image relative to the imaging lens.

14. The method of claim 13, including selectively activating and/or deactivating one or more of the one or more LEDs.

15. The method of claim 13, wherein coupling the light includes embedding at least one of the one or more LEDs into an input face of the light pipe.

16. The method of claim 13, wherein coupling the light includes embedding at least one of the one or more LEDs into a side of the light pipe.

17. The method of claim 13, including:

forming the light pipe from a first light pipe and one or more secondary light pipes coupled to or formed integral with the first light pipe; and

wherein said coupling light into the light pipe includes coupling light into the one or more secondary light pipes and then into the first light pipe.