USOO6979104B2 (12) United States Patent (10) Patent No.: US 6,979,104 B2 Brass et al. (45) Date of Patent: Dec. 27, 2005 (54) LED INSPECTION LAMP FOREIGN PATENT DOCUMENTS CA 2200364 5/1997 (75) Inventors: Jack Brass, Toronto (CA); Richard J. CA 2200365 5/1997 Doran, Wrotham Heath (GB); Donald CA 2284.87O 9/1998 L. Klipstein, Upper Darby, PA (US); CA 228O398 4/2000 Thomas M. Lemons, Marblehead, MA CA 24058O2 10/2001 (US) DE 25 42 220 A 3/1977 DE 299 574 AS 4/1992 (73) Assignees: R.J. Doran & Co. LTD (GB); DE 200 21934 U1 4/2001 Brasscorp Limited (CA) DE 2O1 10813 U1 9/2001 EP O 523 927 A2 1/1993 Notice: Subject to any disclaimer, the term of this EP 1 059 202 A2 12/2000 patent is extended or adjusted under 35 GB 810256 3/1959 WO WO 98/39636 9/1998 U.S.C. 154(b) by 0 days. WO WO 99/35486 7/1999 WO WOO152605 A2 7/2001 (21) Appl. No.: 10/029,803 WO WO 0181973 A1 11/2001 WO WO 03/004932 A1 1/2003 (22) Filed: Dec. 31, 2001 WO WO 03/02548 3/2003 (65) Prior Publication Data OTHER PUBLICATIONS US 2003/0123254A1 Jul. 3, 2003 Craig Johnson, LEDTronics Flash LED, The LED Museum, pre-Sep. 4, 2000, http://ledmusum.home.att.net/tronics.htm. (51) Int. Cl................................................... F21V 9/00 (Continued) (52) U.S. Cl. ....................... 362/231; 362/184; 362/244; Primary Examiner Alan Cariaco 362/804 ASSistant Examiner-Guiyoung Lee (74) Attorney, Agent, or Firm- Katten Muchin Rosenman (58) Field of Search ................................. 362/555,558, LLP 362/119, 120, 187, 804, 84, 183, 184, 231, (57) ABSTRACT 244, 259, 800 An LED inspection lamp has plurality of LED sources for (56) References Cited emitting electromagnetic radiation at different peak wave lengths for causing visible fluorescence in different leak U.S. PATENT DOCUMENTS detection dyes. A lens is associated with each LED. Radia 3,808.434 A 4/1974 Gutiber tion passing through lenses is Superimposed in target area at 4,185,891 A 1/1980 Kaestner target distance. Another LED inspection lamp has plurality 4,826.269 A 5/1989 Streifer et al. of LEDs emitting electromagnetic radiation at a peak wave 4,935,665 A 6/1990 Murata length. A lens adaptor has lens housing for attachment to 4963,798 A 10/1990 McDermott LED inspection lamp with a single LED for causing visible 5,092,331 A 3/1992 Nakamura et al. fluorescence, and a lens. Substantially all of the radiation 5,289,082 A 2/1994 Komoto 5,749,830 A 5/1998 Kaneko et al. from the LED passes through the lens and is focused in a 5,806.961. A * 9/1998 Dalton et al. ............... 362/183 target area at a target distance from the lenses. LED spot 5,954.206 A 9/1999 Mallon et al. .............. 209/580 lights have a similar configuration. (Continued) 55 Claims, 7 Drawing Sheets -10 12 107-a- 17 US 6,979,104 B2 Page 2 U.S. PATENT DOCUMENTS OSRAM SYLVANIA, Preliminary data sheet for 5,975,712 A 11/1999 Shiao OS-WLO1A, Dated Feb. 25, 2000. 5.984,861 A 11/1999 Crowley LED Museum at http://ledmuseum.home.att.net/ledleft.htm 6,095,661 A 8/2000 Lebens et al. printed Feb. 27, 2002. 6,142,650 A 11/2000 Brown et al. ............... 362/259 D434,868 S 12/2000 Trigiani Product pages for Dorcy “Cool Blue' at http://www.dorcy 6,183,086 B1 2/2001 Neubert .com/led%20new.htm printed Feb. 27, 2002. 6,200,134 B1 3/2001 Kovac et al. 6,250.771 B1 6/2001 Sharrah et al. Saftey LED Hi-Power Flash LED Flashlights at http://se 6,305,818 B1 10/2001 Lebens et al. cure.implex.net/NBAComputers/browse.cfm?Catego 6,402,347 B1 6/2002 Maas et al. ................. 362/294 ryID=8 printed Dec. 10, 2001. 6,468,077 B1 10/2002 Melikechi et al. 6,485,160 B1 11/2002 Sommers et al. ........... 362/184 Review of LEDTronics Mini-Flash LED at http://ledmuse 6,491,408 B1 * 12/2002 Cooper et al. .............. 362/184 um.home.att.net/flashled.htm printed Dec. 10, 2001. 6,590,220 B1 7/2003 Kalley et al. ........... 250/504 H Michael Sayer et al. Measurement, Instrumentation and 6,710,363 B1 3/2004 Trigiani Experiment Design in Physics and Engineering. Prentice 2002/OO19396 A1 12/2002 Reiff et al. ................. 362/246 2003/0098425 A1 5/2003 Sosinsky Hall of India, New Delhi, 2000, pp. 197-198. (ISBN 2003/O123254 A1 7/2003 Brass et al. ................. 362/231 81–203–1269–4). Lewis R. Koller. Ultraviolet Radiation. (2nd ed.) John Wiley OTHER PUBLICATIONS & Sons, New York. 1965, pp. 158-181. Hi-Power FlashLED(R) Flashlights, LEDTronics, Inc., date unknown, http://www.netdisty.net/ds/filt-3001/default.asp. * cited by examiner U.S. Patent Dec. 27, 2005 Sheet 1 of 7 US 6,979,104 B2 U.S. Patent Dec. 27, 2005 Sheet 2 of 7 US 6,979,104 B2 ON / OFF F. G. 7 U.S. Patent Dec. 27, 2005 Sheet 3 of 7 US 6,979,104 B2 U.S. Patent Dec. 27, 2005 Sheet 4 of 7 US 6,979,104 B2 D -N-- O3 O M P O O F. G. 12 U.S. Patent Dec. 27, 2005 Sheet 5 of 7 US 6,979,104 B2 LENGTSEF) 4O7 "-run 405 -------- 1403 OBJECT (OD) IMAGE DISTANCE (D) y 1603 1605 t -c: = . BEAM s |-- ----- OD FG 16 mamma-morrow U.S. Patent Dec. 27, 2005 Sheet 6 of 7 US 6,979,104 B2 Fig. 19 EX ki& as SS &SS 203 Fig. 20 U.S. Patent Dec. 27, 2005 Sheet 7 of 7 US 6,979,104 B2 to 22O3 FG. 22 US 6,979,104 B2 1 2 LED INSPECTION LAMP of materials used for leak detection. Such inspection lamps have their own disadvantages Such as the cost of the Special discharge light Sources having Sufficient intensity, the added FIELD OF THE INVENTION cost of electrical components required for operation of Such light Sources, a requirement for Some Such light Sources to This invention is related to the general field of inspection spend time wanning up to a required elevated operating lamps for detection of fluorescent materials, and in particular temperature in order to properly function, and the tendency to the field of inspection lamps having light emitting diodes of many discharge light Sources to Specialize in production which produce radiation Suitable for exciting the fluorescent of wavelengths not effectively utilized by all popular fluo materials to be detected by Such lamps. rescent dyes. There is a need to derive the full benefit of BACKGROUND OF THE INVENTION utilizing LED light Sources in inspection lamps. There is also a need to retain Some of the benefits of traditional light Detection of leaks in Systems containing fluids under Sources. It is an object of the invention to address these or preSSure is often accomplished by causing visible fluores other issueS associated with LED inspection lamps. cence of fluorescent dyes that are added to the fluid in the 15 System. Such Systems may be, for example, refrigeration SUMMARY OF THE INVENTION Systems where the fluid under pressure is a refrigerant and In a first aspect the invention provides an inspection lamp leakage results in the fluid becoming an invisible gas upon having light emitting diodes as a Source of radiation Suitable escape. The invisibility of leaked fluid can impair detection for causing visible fluorescence of fluorescent materials, of the leak. Addition of a fluorescent dye to the refrigerant where Said light emitting diodes are Substantially non allows easier detection of leaks by illuminating possible identical in Spectral characteristics of their emitted radiation, leakage points with radiation that causes the fluorescent dye Such that at least one but not all of Said light emitting diodes to visibly fluoresce at the site of the leak. in Said inspection lamp produce wavelengths of radiation Leak detection by means of use of a fluorescent dye is also that are favorable for causing visible fluorescence of Some used in Systems other than refrigeration Systems, Such as 25 fluorescent materials, and Such that one or more different automotive cooling Systems and in engines having a lubri Said light emitting diodes in Said inspection lamp produce cant that is under preSSure. substantially different wavelengths of radiation which are There are many inspection lamps currently available for more favorable than the wavelengths of first said light the purpose of illuminating potential leak Sites with radiation emitting diode(s) for causing visible fluorescence of Some cause visible fluorescence of fluorescent dyes. It is desirable fluorescent materials other than first Said fluorescent mate to minimize the size, weight, cost, heat production and rials. power consumption of Such inspection lamps while having At least one light emitting diode may have a peak emis adequate output from Such lamps at wavelengths Suitable for Sion wavelength in the ultraViolet and at least one light causing visible fluorescence of dyes used for leak detection. emitting diode may have a peak emission wavelength that is Light emitting diodes (LEDs) are used as a Source of light 35 visible but suitable for causing visible fluorescence of fluo for Such inspection lamps. LEDs are more efficient at rescent materials. producing desired wavelengths than other light Sources used At least one light emitting diode may produce mostly blue in Such inspection lamps.