# US 7,077,525 B2 · Led-based flashlight > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,077,525 B2 - Document ID: US7077525B2 - Status: Granted - Kind: B2 - Application number: 10/794,073 - Filed: 2004-03-05 - Published: 2005-01-13 - Granted: 2006-07-18 - Earliest claimed: 2001-02-06 - Assignees: Optics 1, Inc. - Inventors: Robert E. Fischer; Greg Moeller; Simon Prince - Web page: https://patentgrep.com/patent/US7077525B2 ## CPC - G02B 27/0961: {Lens arrays (lens arrays per se G02B3/0006)} - F21L 4/00: Electric lighting devices with self-contained electric batteries or cells - F21L 4/027: {the light sources being a LED} - F21V 5/04: of lens shape - F21V 9/40: with provision for controlling spectral properties, e.g. colour, or intensity - F21V 14/065: {in portable lighting devices} - G02B 27/0994: {Fibers, light pipes (optical fibers per se G02B6/02)} - G03B 21/2013: {Plural light sources} - G03B 21/2033: {LED or laser light sources} - G03B 21/208: {Homogenising, shaping of the illumination light} - F21V 11/08: using diaphragms containing one or more apertures - F21V 2200/13: the light being emitted at the end of the guide - F21V 2200/17: characterised by the admission of light into the guide - F21Y 2115/10: Light-emitting diodes [LED] - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - F21L: LIGHTING DEVICES OR SYSTEMS THEREOF, BEING PORTABLE OR SPECIALLY ADAPTED FOR TRANSPORTATION - F21V: FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR - G03B: APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR (optical parts of such apparatus G02B; photosensitive materials or processes for photographic purposes G03C; apparatus for processing exposed photographic materials G03D) - F21Y: INDEXING SCHEME ASSOCIATED WITH SUBCLASSES F21K, F21L, F21S and F21V, RELATING TO THE FORM OR THE KIND OF THE LIGHT SOURCES OR OF THE COLOUR OF THE LIGHT EMITTED ## 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 ### Claim 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. ### Claim 2 (depends on 1) 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. ### Claim 3 (depends on 1) The flashlight of claim 1, wherein the LED array includes at least two LEDs having a different color. ### Claim 4 (depends on 3) The flashlight of claim 3, wherein the LED array includes at least one red, one green and one blue LED. ### Claim 5 (depends on 1) 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. ### Claim 6 (depends on 1) The flashlight of claim 1, wherein the one or more LEDs are dies. ### Claim 7 (depends on 1) The flashlight of claim 1, wherein the one or more LEDs are packaged. ### Claim 8 (depends on 1) 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. ### Claim 9 (depends on 1) 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. ### Claim 10 (depends on 9) 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. ### Claim 11 (depends on 1) 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. ### Claim 12 (depends on 11) 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. ### Claim 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. ### Claim 14 (depends on 13) The method of claim 13, including selectively activating and/or deactivating one or more of the one or more LEDs. ### Claim 15 (depends on 13) 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. ### Claim 16 (depends on 13) 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. ### Claim 17 (depends on 13) 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.