LED-based dental exam lamp with variable chromaticity

Abstract

An electrically powered light source including a light emitting diode (led) having variable chromaticity, which is adapted for use in a dental operatory. A dental operatory lamp includes a thermally conductive housing having a front directed toward the operating area and a rear away from the operating area; a generally elliptical reflector located on the rear of the thermally conductive housing; at least one heat pipe; a plurality of color leds projecting light toward the elliptical reflector, the plurality of leds being in thermal contact with the at least one heat pipe; and an optical light guide for combining light from said leds. Another embodiment of the lamp includes at least two user selectable light spectra, one of said spectra providing white light with color temperature in the range 4000° K-6000° K and one spectra having reduced output in the wavelength range 400-500 nm.

Description

RELATED U.S. APPLICATION DATA

This application is a andFIG. 6 illustrates a side view of a currently preferred embodiment, generally indicated at 1000, of a light source structure constructed according to principles of the invention. Light source structure 1000 may generally be characterized as a lamp. Lamp 1000 is powered by electricity, and functions to provide illumination to a work area disposed a distance from the lamp front, generally indicated at 1002. Desirably, the work area illuminated by lamp 1000 is shadow-free, and appears relatively uniform in illumination color and intensity. For most applications, the illuminated target work area is considered to have an approximately flat footprint and a depth normal to that footprint. That is, the illuminated region is generally structured to encompass a volume disposed proximate the footprint.

Illustrated lamp 1000 includes attachment structure, generally indicated at 1004, operable to connect lamp 1000 to suspension structure in the work area. Illustrated attach structure 1004 is carried at a back 1006 of lamp 1004, although any convenient arrangement is operable. Typical suspension structure in a dental operatory permits a user to orient the lamp in space operably to aim the light output of lamp 1000 at the desired target area. Certain embodiments of the invention provide a lamp having reduced weight and/or intrusive volume compared to commercially available lamps. Such reduced weight lamps permit a corresponding reduction in mass of the lamp suspension arrangement, thereby increasing ease of manipulation of the lamp to orient its output toward a target.

Lamp 1000 includes a plurality of light modules 1008 that may be disposed in an array and tilted along an arcuate path 1010 to aim their collective light outputs to impinge on a desired target footprint. Illustrated light modules 1008 are sometimes also called reflective modules. One row of modules 1008 is visible in FIG. 6, although any number of such rows may be repeated in a columnar, staggered, or other arrangement in space to form a 3-dimensional lamp body providing the desired luminescent output.

One currently preferred lamp assembly 1000 includes 3 rows forming 5 columns of modules 1008, for a total of 15 modules in the lamp. Such modules 1008 are desirably spaced apart from each other and aimed in harmony to form a shadow-free illumination of a target region. In the context of this disclosure, the term “shadow-free” means that an object, such as a tool or a user's hand, casts essentially no shadow when placed between the lamp and its illuminated target. It is currently preferred for an output of each module to be shaped to substantially illuminate the entire target footprint. Therefore, the target footprint is fully illuminated by the sum of the outputs of modules 1008. In such an arrangement, an object blocking light emitted by one, or even most, of the modules 1008 still would not cast a shadow on the target footprint. A path along a column between rows may be a straight line, although it is currently preferred that such path (not illustrated, but similar to path 1010) also is arcuate.

In use in an environment such as a dental operatory, it is preferred to provide a front shield 1012 as a protective cover to block migration of dust and contaminated aerosols into the lamp interior. A front surface of such a shield 1012 may be structured to provide an easily cleanable surface, whereby to maintain sterility of the operatory area. In certain embodiments, shield 1012 may incorporate one or more lenses to focus, or otherwise modify, the light output of lamp 1000. Whether or not a focusing lens is provided, a shield made from LEXAN®, or other similar optically useful and formable material, desirably is provided to completely encase the front of a dental lamp to resist contamination of, and to facilitate cleaning of, the lamp. Illustrated shield 1012 is injection molded, and includes focusing lenses for each of the modules 1008 in a unitary part. Desirably, shield 1012, or a portion of lamp housing 1014, is hinged, or otherwise openable by a user, to provide access to the interior of lamp 1000 for maintenance or replacement of a light generating element.

With reference to FIG. 7, an LED 1018 emits light indicated by a plurality of rays 1020. An operable LED includes a 3 watt LED such as that sold by Lumileds Lighting US, LLC under the Brand name Luxeon, part number LXHL-LW3C.

Typically, a reflective element, generally indicated at 1022, is provided to direct the LED's light output toward a target. A focusing lens 1024 may be included in an arrangement effective to collimate rays 1020, and further direct them to an illuminated area indicated at 1026. In certain embodiments of the invention, area 1026 corresponds to the target footprint of the lamp 1000. In such case, it is desired that the illumination emitted from each module 1008 is substantially uniform over area 1026. Certain rays 1028 may be emitted in a direction other than desired for impingement on area 1026. Such rays 1028 are characterized as stray light. As indicated by the illustrated collection of rays 1020, area 1026 sometimes has a higher intensity of illumination at its center, and may fade to a decreased intensity near its perimeter. In another embodiment, the LED 1018, mirror 1022, and all associated optics are arranged in harmony to produce a substantially uniform intensity over its illuminated footprint at a selected focal distance.

Another exemplary light module 1008 is illustrated in FIG. 8. Housing 1032 of illustrated module 1008 includes a portion that forms a component stray light tube 1034. An interior surface 1036 of tube 1034 may be reflective, but desirably is arranged to resist reflection of incident stray light rays 1028 to reduce emission of such stray rays outside the target footprint. A preferred stray light tube 1034 provides a black, or essentially light absorbing, surface 1036 to resist reflection of stray light rays 1028. It is within contemplation for a stray light tube 1034 to be formed as a distinct component. However, including the stray light tube as a portion of the housing 1032 reduces part count and cost, and simplifies assembly of a lamp 1000.

LED 1018 is typically mounted with respect to housing 1032 by a conveniently structured foundation 1038. Desirably, foundation 1038 is structured to provide simple and rapid installation and removal of LED 1018, and includes connection structure for the electricity supplied to the LED. It is further desirable for foundation 1038 to be formed from a material capable of conducting heat. Advantageously, foundation 1038 and housing 1032 may be structured and arranged to dissipate any heat generated by LED 1018 in a direction away from the front of the lamp 1000.

Lens 1044 may be arranged to disperse, focus, collimate, color, or otherwise modify a characteristic of light 1020 passing therethrough. Alternatively, or in addition, lens 1044 may be configured as a protective shield for a module 1008, or lamp 1000. In certain cases, a collimating lens may be disposed in the space 1046 located between LED 1018 and a distal end 1048 of module 1008. Desirably, such collimating lens is placed in proximity to the discharge opening of the parabolic reflector 1022 to reduce a length of the light module 1008. In a currently preferred embodiment of lamp 1000, modules 1008 are about 2½ inches in length, and approximate the size in a thickness direction of the lamp 1000.

FIGS. 9-11 illustrate configurations of collimating lenses of use in certain embodiments constructed according to principles of the invention. Such lenses typically are structured to direct the LED's light output toward a target, and permit formation of lamp 1000 in a compact form factor. A pair of operable collimating lenses, configured as TIR lenses, is illustrated in FIGS. 9-11. The first collimating TIR lens 1052 (<4.5 deg. FWHM) is illustrated in end and section views in FIGS. 9 and 10, respectively. The second TIR lens (<2 deg. FWHM), illustrated in cross-section in FIG. 11 and is generally indicated at 1054. Such lenses permit a reduction in length of the stray light tube or equivalent portion of a housing 1032.

Although the foregoing description contains many specifics, these are not to be construed as limiting the scope of the present invention, but merely as providing certain representative embodiments. Similarly, other embodiments of the invention can be devised which do not depart from the spirit or scope of the present invention. The scope of the invention is, therefore, indicated and limited only by the appended claims and their legal equivalents, rather than by the foregoing description. All additions, deletions, and modifications to the invention, as disclosed herein, which fall within the meaning and scope of the claims, are encompassed by the present invention.

Claims

1. A dental operatory lamp used to illuminate an operating area comprising: a plurality of color leds; an optical light guide for combining light from said leds; and at least two user selectable light spectra, one of said spectra providing white light with color temperature in the range 4000° K-6000° K and one spectra having reduced output in the wavelength range 400-500 nm.

2. The dental operatory lamp of claim 1, wherein the user selectable light spectra comprises varying ratios of at least three colors emanating from the color leds.

3. The dental operatory lamp of claim 1, wherein the user selectable light spectra comprises various ratios of red, blue, green, and amber light emanating from the color leds.

4. A dental operatory lamp used to illuminate an operating area comprising: a housing having a front directed toward the operating area and a rear away from the operating area; a reflector module located at the rear of the housing; a plurality of color light emitting diodes (leds) on the reflector module; and an optical light guide configured to direct the light from the color leds toward the front of the lamp in a pattern that focuses white light from the lamp to a central area of illumination of high intensity, with significantly reduced intensity illumination outside the central area; an attachment structure disposed on the housing; and a suspension structure connected to the attachment structure and arranged to suspend the lamp in a dental operatory.

5. The dental operatory lamp of claim 4, wherein the optical light guide produces at least three operating modes with different light characteristics.

6. The dental operatory lamp of claim 4, wherein the lamp produces white light with coordinated color temperatures of between 4000° K and 6000° K and maintaining a color rendering index in excess of 75.

7. The dental operatory lamp of claim 4, wherein the a user selectable light spectra comprises various ratios of red, blue, or green, or amber light emanating from the color leds.

8. A dental operatory lamp used to illuminate an operating area comprising: a housing having a front directed toward the operating area and a rear away from the operating area; a reflector module located in the housing; and a plurality of color light emitting diodes (leds) on the reflector module, wherein said lamp comprises different operating modes comprising a first operating mode having light characteristics for curing of a dental adhesive and a second operating mode having light characteristics that do not cure the dental adhesive.

9. The dental operatory lamp of claim 8, wherein said first operating mode comprises a cool white mode or a warm white mode.

10. The dental operatory lamp of claim 9, wherein said cool white mode comprises producing a light spectra in the range of 4000-6000 degrees K.

11. The dental operatory lamp of claim 9, wherein said warm white mode comprises producing a light spectra in the range of 4000-6000 degrees K.

12. The dental operatory lamp of claim 9, wherein said cool white mode and warm white mode comprise producing a light spectra with 70 or greater color rendering index.

13. The dental operatory lamp of claim 8, wherein said second operating mode comprises light having flux below 500 nm.

14. The dental operatory lamp of claim 8, further comprising a light guide for combining light from said leds.

15. The dental operatory lamp of claim 14, wherein said light guide is configured to direct light from said leds toward the front of said housing.

16. The dental operatory lamp of claim 8, wherein said plurality of color leds comprises leds that emit at least three colors.

17. The dental operatory lamp of claim 16, wherein said at least three colors comprises at least three of blue, green, amber, or red.

18. The dental operatory lamp of claim 17, wherein said at least three colors comprises blue, green, amber, and red.

19. The dental operatory lamp of claim 8, wherein said different operating modes comprise at least two user selectable light spectra, one of said spectra providing white light with color temperature in the range 4000° K-6000° K and one spectra having reduced output in the wavelength range 400-500 nm.

20. A dental examination lamp comprising:

a housing;

a plurality of tubes within the housing and arranged in a generally side-by-side configuration, each tube having an interior, a first end, and a second end, the second end open to the transmission of light from the interior of the tube, each tube being absorptive, generally non-reflective, or both absorptive and generally non-reflective;

a plurality of light emitting diodes (leds), each of the leds being arranged to direct light through at least part of one of the tubes and out of the lamp

an attachment structure disposed on the housing; and

a suspension structure connected to the attachment structure and arranged to suspend the lamp in a dental operatory.

21. The lamp of claim 20, wherein the plurality of tubes are positioned with their longitudinal axes aligned to direct light toward predetermined points to form a predetermined light pattern within an examination area.

22. The lamp of claim 20, further comprising a plurality of lenses, with at least one lens per tube located proximate to the second end thereof and adapted to direct the light from the plurality of leds out of the lamp in a pattern that casts illumination over an examination area.

23. The lamp of claim 20, further comprising a lens member at a front of the lamp presenting a plurality of individual lens sections over a face thereof arranged in a pattern corresponding to the position of the plurality of tubes, each lens section being aligned with a respective tube and adapted to direct light from that tube out of the lamp in a pattern that casts illumination over an examination area.

24. The lamp of claim 20, further comprising a collimating element arranged to collimate light emanating from an led.

25. The lamp of claim 20, further comprising a lens adapted to color the light directed out of the lamp.

26. The lamp of claim 20, wherein an interior surface of at least one of the plurality of tubes is black.

27. The lamp of claim 20, wherein the plurality of tubes includes at least five tubes.

28. The lamp of claim 20, wherein the plurality of tubes includes at least five columns of tubes.

29. The lamp of claim 20, wherein an interior surface of at least one of the plurality of tubes is absorptive.

30. The lamp of claim 20 wherein the light has reduced output at wavelengths that cure adhesives or composites.

31. A dental examination lamp comprising:

a housing;

a plurality of stray light tubes within the housing, each of the plurality of stray light tubes adapted to reduce emission of stray light rays outside a target footprint;

a plurality of light emitting diodes (leds), at least one led for each stray light tube, wherein the plurality of stray light tubes is arranged in a generally side-by-side configuration;

an attachment structure disposed on the housing; and

a suspension structure connected to the attachment structure and arranged to suspend the lamp in a dental operatory.

32. The lamp of claim 31, wherein at least one of the stray light tubes comprises an absorptive or generally non-reflective interior surface.

33. The lamp of claim 31, further comprising a collimating element arranged to collimate light emanating from at least one of the plurality of leds.

34. The lamp of claim 31, wherein the plurality of stray light tubes are positioned with their longitudinal axes aligned toward predetermined points to direct the light from the plurality of leds out of the lamp to form a predetermined light pattern within an examination area.

35. The lamp of claim 31, further comprising a plurality of lenses, each located at an end of a stray light tube, the plurality of lenses adapted to direct the light from the plurality of leds out of the lamp in a predetermined pattern that casts illumination over an examination area.

36. The lamp of claim 35, wherein the plurality of stray light tubes and the plurality of lenses form a plurality of assemblies, each assembly adapted to direct light passing through the assembly.

37. The lamp of claim 31, further comprising a lens adapted to color light emanating from at least one of the plurality of leds.

38. The lamp of claim 31, wherein an interior surface of at least one of the plurality of stray light tubes is black.

39. The lamp of claim 31, wherein the plurality of stray light tubes includes at least five tubes.

40. The lamp of claim 31, wherein the plurality of stray light tubes includes at least five columns of tubes.

41. A dental examination lamp, comprising:

a housing;

a plurality of tubes mechanically coupled to the housing and arranged in a generally side-by-side configuration, each tube having an interior, a first end, and a second end, the second end of each tube being open to transmission of light from the interior of the tube, each tube being optically absorptive, generally non-reflective, or both optically absorptive and generally non-reflective;

a plurality of light emitting diodes (leds), each of the leds being arranged to direct light through at least part of one of the tubes and out of a front of the lamp;

an attachment structure disposed on the housing; and

a suspension structure connected to the attachment structure and arranged to suspend the lamp in a dental operatory.

42. The lamp of claim 41, further comprising a lens adapted to color light emanating from at least one of the plurality of leds.

43. The lamp of claim 41, wherein an interior surface of at least one of the plurality of tubes is black.

44. The lamp of claim 41, wherein the plurality of tubes includes at least five tubes.

45. The lamp of claim 41, wherein the plurality of tubes includes at least five columns of tubes.

46. A method of illuminating a dental operating area, the method comprising:

providing a dental operatory lamp, the dental operatory lamp including

a plurality of stray light tubes adapted to reduce emission of stray light rays outside a target footprint, the plurality of tubes arranged in a generally side-by-side configuration, and

at least one light emitting diode (led) arranged to direct light through each stray light tube and out of the lamp;

providing an attachment structure disposed on the lamp;

providing a suspension structure connected to the attachment structure;

by the suspension structure, suspending the lamp in a dental operatory

generating light via each of the at least one leds; and

illuminating a patient's mouth with the light.

47. The method of claim 46 wherein providing the dental operatory lamp comprises providing a plurality of stray light tubes with an absorptive surface.

48. The method of claim 46, further comprising providing a collimating element to collimate light emanating from at least one of the plurality of leds.

49. The method of claim 46, further comprising providing the plurality of stray light tubes with their longitudinal axes aligned toward predetermined points to direct the light from the plurality of leds out of the lamp to form a predetermined light pattern within an examination area.

50. The method of claim 46, further comprising providing a plurality of lenses, each at an end of a stray light tube, the plurality of lenses adapted to direct the light from the plurality of leds out of the lamp in a predetermined pattern that casts illumination over an examination area.

51. The method of claim 50, further comprising providing a plurality of assemblies from the plurality of tubes and the plurality of lenses and dispersing light passing through each assembly.

52. The method of claim 46, further comprising modifying a color of light emanating from at least one of the plurality of leds via a lens.

53. The method of claim 46, wherein each of the plurality of tubes has an interior surface and the interior surface of at least one of the plurality of tubes is black.

54. The method of claim 46, wherein the plurality of tubes includes at least five tubes.

55. The method of claim 46, wherein the plurality of tubes includes at least five columns of tubes.

56. The method of claim 46 wherein providing the dental operatory lamp comprises providing a plurality of stray light tubes with a generally non-reflective surface.

57. The method of claim 46 wherein illuminating a patient's mouth comprises aiming the light at the patient's mouth while reducing stray light entering the patient's eyes.

58. The method of claim 46 wherein the illuminating step comprises illuminating the patient's mouth with light having reduced output at wavelengths that cure adhesives or composites.

59. The method of claim 46 wherein the illuminating step comprises selecting from a plurality of light spectra a light spectrum with reduced output at wavelengths that cure adhesives or composites.