GB2127949A - Illuminating device - Google Patents

Abstract

The invention provides an illuminating device having an illumination pattern that is the same after partial loss of illumination as it is during total illumination. The illuminating device includes at least two light sources (48), apparatus for gathering the light from the light sources and transmitting the gathered light to light mixing apparatus (56). The light mixing apparatus mixes the light gathered from each source as it transmits it to apparatus for directing the mixed light onto a work area. The light gathering and light mixing apparatus can be a furcated fiber optic bundle (50) having fiber optics that are woven together or a light pipe having several inputs, one for each light source, and at least one output for transmitting the light to the light directing apparatus. The device is especially suitable for operating theatre lamps. <IMAGE>

Description

SPECIFICATION Illuminating device having multiple light sources This invention relates to illuminating devices and, more particularly, to an illuminating device having multiple light sources.

It is necessary to provide a work area with a high level of illumination to perform many types of work. In particular, it is necessary to provide a high level of illumination to the area of the human body on which a surgeon is operating to permit the surgeon to properly view the site of the incision and operate effectively. Moreover, in some work environments, such as surgery on a living being, a total loss of lighting-even if it is temporary-is unacceptable.

Workers in the art have developed illuminating devices, such as spotlights and flood lights, in an attempt to meet the needs identified above. One such device includes a single high-intensity lighting source that provides a work area with a high level of illumination.

However, the eventual total loss of illumination due to failure of the single light source makes its use in critical operations less than totally desirable. Accordingly, workers in the art have developed illuminating devices having multiple light sources to provide a high level of illumination to the work area, and to minimize the risk of total loss of illumination.

However, when one of the multiple light sources fails, the illuminated area becomes distorted and unduly distracts the worker.

Moreover, when the worker places an object between the sources of light and the work area, the object casts multiple shadows thereby lowering the effectiveness of the worker.

Accordingly, there exists a need for a light that provides a high level of illumination to a work area, that minimizes the risk of total loss of illumination of the work area, and that maintains the pattern of illumination even upon partial loss of illumination.

The present invention provides an illuminating device having multiple light sources for providing a high level of illumination to a work area and minimizing the risk of total loss of work area illumination. Moreover, the pattern of illumination provided by the illuminating device after a partial loss of illumination remains the same as during total illumination.

Although the present invention is particularly useful for illuminating the area of a human body upon which a surgeon is operating, it is useful in any application where consistent high level work area illumination is desirable.

The illuminating device of the present invention includes at least two sources of light and apparatus for directing light onto the work area. The number of light sources included with the present invention can be chosen to meet the needs of a particular application. The light directing apparatus can be any suitable known apparatus including systems of optical reflectors. The present invention includes apparatus for gathering the light produced by each of the light sources and transmitting the gathered light to light mixing apparatus. The light mixing apparatus mixes the light gathered from each light source into a single light beam. The light gathering and mixing means can be a plurality of fibre optics arranged in a furcated bundle having at least two inputs and at least one output. Each of the light sources directs light into a group of the fibers.The fibers from each group are interwoven in the output bun dle of the furcated bundle with those of each other group to provide a single mixed light beam.

Alternately, the light gathering apparatus is at least two light tubes that receive the light produced by the light sources and transmit the gathered light to the light mixing apparatus. The light mixing apparatus can be a light tube having a number of inputs for accepting the gathered light and mixing it as it is transmitted within the tube and directing the mixed light onto the light directing apparatus.

It is particularly desirable to use the present invention in place of the single light source of the illuminating device disclosed in U.S. Patent No. 4,037,096 issued on July 19, 1977, to American Sterilizer Company of Erie, Pennsylvania (hereinafter referred to as "No.

'096"). The light disclosed in No. '096 dicloses a light having a folded optical system comprising three reflectors. Such a system provides a work area having a uniform pattern of illumination. Moreover, an object that is placed between the light disclosed in No.

'096 and the work area lit thereby will, essentially, cast only one shadow. Use of the present invention in place of the single source of the light disclosed in No. '096 provides such characteristics even upon a partial loss of illumination.

In addition to the advantages of the present invention discussed above commercially available, rather than specially manufactured, filters and lenses can be included with the present invention to provide heat removal, colour correction, or focusing.

Accordingly, the single light source of single light source illuminating devices can be replaced with the present invention to minimize the risk of total loss of illumination.

Further, the present invention is useful for providing an illuminated work area having a pattern of illumination that is the same upon partial loss of illumination as during total illumination. When used herein, the term "folded optical system" means a system of reflectors shown in U.S. Patent No.

4,037,096 and Fig. 1 herein. When used herein, the term "fiber optic" means a light transmitting fiber.

BRIEF DESCRIPTION OF THE DRAWINGS The following detailed description of the preferred embodiments of the present invention can be understood better by referring to the accompanying drawings, in which: Figure 1 is a side sectional view of an illuminating device embodying the present invention; Figure 2 is a side elevational view of a portion of the illuminating device shown in Fig. 1 showing the mounting arrangement for the light sources; Figure 3 is a bottom view of a portion of the illuminating device shown in Fig. 1 showing the mounting arrangement for the light sources and the output bundle; Figure 4 is a top view of the light sources, fiber optic bundle, and output filter shown in Fig. 1; Figure 5 is a side view of a portion of the illuminating device shown in Fig. 1 showing the light sources, a portion of an input bundle and the mountings therefor;; Figure 6a through 6d illustrate the arrangement of the fiber optics within the four input bundles; Figure 7 illustrates the disposition of the fiber optics of the four input bundles at the output of the output bundle; Figure 8 shows in section a portion of an illuminating device employing an alternate embodiment of the present invention; and Figure 9 shows the mounting for the light sources of the illuminating device shown in Fig. 8.

DETAILED DESCRIPTION OF THE PRE FERRED EMBODIMENTS Figs. 1 through 5 show the present invention as it can be used with an illuminating device of the type shown in the drawings of U.S. Patent No. 4,037.096 ("No.'096) issued to American Sterilizer Company. U.S.

Patent No. 4,037,096 is hereby incorporated herein by reference. The present invention replaces sources 20, 60 or 102 of No. '096.

Generally, illuminating devicel0 includes a source assembly 1 2, a conical reflector 1 4 secured to mounting 34, and a reflector 1 6.

Source assembly 1 2 provides a beam of light 1 8 that is reflected by conical reflector 14 toward reflector 1 6 which reflects light beam 18 toward the work area. Such a system of reflectors shall be referred to herein as a folded optical system and provides a work area having uniform illumination. Moreover, such a system creates a single shadow when an object is placed between illuminating device 10 and the work area.

Illuminating device 10 also includes an external housing 20 that, together with reflector 16, defines fluid passage 22 through which heat can be transmitted in the direction of arrows 24. Housing 20 can be secured to any suitable support. Preferably, reflector 1 6 is constructed from a material that reflects visible light but allows infrared light to pass to enhance the heat removal properties of illuminating device 1 0. Ports 26 are provided to enhance heat flow in passages 22 by providing convection currents therein. Outlet ports 28 enable convection currents to leave passage 22. A light transmitting dust shield 30 is joined at its edges to housing 20 and reflector 16 by a gasket 32. Dust shield 30 is secured at its interior in any suitable fashion to mounting 34.Mounting 34 also provides support for handle 36 which is used to adjust the position of illuminating device 10 when it is fixed to apparatus that permits such adjustment. Mounting 34 is secured within illuminating device 10 by conical reflector 14, shield 30, handle 36, and spacers 38.

Spacers 38 are secured within illuminating device 10 to housing 20 and reflector 1 6 by any suitable means such as bolts 40. Access door 46 can be provided to protect source assembly 1 2 while providing access thereto and an outlet for heat transmitted through passages 22.

Source assembly 1 2 includes light sources 48 which are mounted on mounting 61.

Although four sources 48 are shown the number thereof chosen depends on the particular application for illuminating device 10. Furcated fiber optic bundle 50 gathers light from sources 48, mixes the gathered light, and directs the mixed light 52 onto conical reflector 1 4. As stated above, conical reflector 14 directs mixed light 52 toward reflector 1 6 which directs mixed light 52 onto the work area and illuminates it uniformly.

Fiber optic bundle 50 comprises a number of fiber optics, each of which extends from a light source 48 to output 54 of output portion bundle 56 of fiber optic bundle 50. The fiber optics originating at each light source 48 are woven together in output portion 56 to intermingle the light gathered from each source and provide a mixed light beam at the bundle output 54. Figs 6athrough 6dand 7 show the input portions 58 of bundle 50 and a cross section of output portion 56. The input sections 58 corresponding to each source 48 are coded to illustrate the manner in which the fiber optics are woven in output portion 56 to achieve a mixed light source at bundle output 54. The mixed nature of light beam 52 exiting bundle output 54 ensures that when one or more sources 48 fail, the work area illumination pattern will remain uniform because the cross section of mixed light beam 52 will remain uniform. Moreover, since the folded optical system of illuminating device 10 sees only a light beam having a reduced flux, and not a distorted one, an object that is placed between illuminating device 10 and the work area will still cast only a single shadow.

Input sections 58 are secured to mounting 61 by plates 60. Plates 60 are secured to support ring 61 which is secured to cover plate 63. Cover plate 63 is secured to housing 20 by bolts 40.

Filtering can be provided to illuminating device 10 to enhance heat removal from illuminating device 10, to achieve colour correction, and to provide specialized focusing, if desired. By fixing a lens or filter 64 to plate 65 or lenses or filters 66 to plates 60 such heat removal, colour correction, or focusing can be easily achieved.

An alternate embodiment of the present invention 70 is shown in Fig. 8. Illuminating device 70 is identical to illuminating device 10 except for source assembly 72 and source mount 49.

Source mount 49 is fixed to cover plate 63 and serves to mount light sources 48 within illuminating device 10. Source assembly 72 includes light pipes 74 which gather light from source elements 48 and tranmit it to output pipe 76. The gathered light is mixed within pipe 76 as it transmits the light and directs it toward conical reflector 1 4. As in illuminating device 10, light pipes 74 and 76 are secured within housing 38 by plate 78.

Plate 78 is fixed within housing 38 in any suitable fashion.

Colour correction, heat removal, or focusing can be achieved with illuminating device 70 in the same fashion as it is achieved with illuminating device 10. In addition, a filter or lens 82 can be secured within light pipe 76 to effect heat removal, colour correction, or focusing.

Claims (11)

1. An illuminating device having apparatus for directing light onto an area comprising in combination at least two sources of light; means for mixing said light and transmitting said mixed light to said light directing apparatus; and means for gathering said light from each of said light sources and transmitting said gathered light to said light mixing means.

2. The illuminating device recited in claim 1 wherein said light gathering means and said light mixing means comprise a plurality of fiber optics arranged in a furcated bundle having at least two inputs and at least one output, each of said light sources directing light into a group of said fibers, said fibers being arranged in said bundle to direct onto said light directing apparatus light that constitutes a mixture of said gathered light.

3. The illuminating device recited in claim 1 wherein said light gathering means is at least two light tubes for receiving said light from said light sources and transmitting said gathered light within said tube to said light mixing means.

4. The illuminating device recited in claim 3 wherein said light mixing means is a light tube having an input for accepting said gathered light from said light gathering tubes, a light mixing portion for transmitting said light along said mixing tube and mixing said gathered light as it is transmitted therethrough, and at least one output for directing said mixed light onto said light directing apparatus.

5. An illuminating device having a folded optical system for illuminating an area comprising in combination at least two light sources; means for mixing the light provided by said sources and transmitting said mixed light to said folded optical system; and means for gathering said light from each of said light sources and transmitting said gathered light to said light mixing means.

6. The illuminating device recited in claim 5 wherein said light gathering means and said light mixing means comprise a plurality of fiber optics arranged in a furcated bundle having at least two inputs and at least one output, each of said light sources directing light into a group of said fibers, said fibers being spatially arranged in said bundle to direct onto said folded optical system light that consitutes a mixture of said gathered light.

7. The illuminating device recited in claim 5 wherein said light gathering means is at least two light tubes for receiving said light from said light sources and transmitting said gathered light within said tube to said light mixing means.

8. -The illuminating device recited in claim 7 wherein said light mixing means is a light tube having an input for accepting said gathered light from said light gathering tubes, a light mixing portion for transmitting said light along said mixing tube and mixing said gathered light as it is transmitted therethrough, and at least one output for directing said mixed light onto said folded optical system.

9. In an illuminating device having at least two sources of light and apparatus for directing said light onto a work area, the improvement comprising: means for mixing said light and transmitting said mixed light to said light directing apparatus; and means for gathering said light from each of said light sources and transmitting said gathered light to said light mixing means.

1 0. Light producing apparatus for an illuminating device having apparatus for directing light onto an area comprising in combination: at least two sources of light; a plurality of fiber optics arranged in a furcated bundle having at least two input bundles, each of said light sources directing light into the fiber optics of at least one input bundle, the fiber optics of said input bundles being woven together to form an output bundle that directs onto said light directing apparatus light that constitutes a mixture of said gathered light.

11. Light producing apparatus substantially as hereinbefore described and as shown in Figs. 1 to 7 or Figs. 8 and 9 of the accompanying drawings.