WO1986005858A1 - High-intensity light source for a fiber optics illumination system - Google Patents

Abstract

A system comprising a high-intensity lamp (24), a focusing reflector (25) for directing focussed light into a light conduit (fiber optic) (30), a rotating fan (42) between the lamp and the light conduit. The system may include a cooling duct (700) that the fan blows through and an air inlet (704) in the housing (702). Further embodiments may include a color wheel (540) or rotating shutter. The system can use either glass or plastic light conduits.

Description

o HIGH-INTENSITY LIGHT SOURCE

4 FOR A FIBER OPTICS ILLUMINATION SYSTEM 5 6 This application is a continuation-in-part of United 7 States Patent Application Serial Number 06/716,575, filed Marc 8 27,. 1985, now abandoned. o 0 BACKGROUND OF THE INVENTION 1 2 1. Field of the Invention 3 4 This invention relates to a high-intensity light source f 5 a fiber optics illumination system for applying light from a 6 high-intensity light source along a predetermined path for 7 illuminating one end of a fiber optics illumination conduit or 8 light conduit. More specifically, the present invention relat 9 to a high-intensity light source for a fiber optics illuminati 0 system wherein an axial flow, propeller-type impeller, that is 1 a fan, is positioned to have its vanes rotated through the gap 2 between the lamp and the light conduit and the light is direct 3 along the predetermined path onto one end of a fiber optics 4 illumination conduit. 5 6 7 8 2. Description of the Prior Art

High-intensity light sources for fiber optics illumination systems are well known in the art. Typical of the fiber optics sources known in the art are those described in U.S. Patent Nos. 3,775,606 and 3,733,481. The fiber optics light console disclosed in U.S. Patent No. 3,775,606 relates to a light source which includes a dual illumination system which permits simultaneous use of two cables with the same console and which enables the user to switch from one cable to another cable in the event of failure of one light source during a surgical operation. The light console employs light and heat shielding means surrounding each of the light sources, and the shielding means function as a heat sink. Preferably, the shielding means may be air cooled to protect the front portion of the console to reduce the temperature thereof. The light console is air cooled by a fan-type motor with the motor located rearward of the light source and the bayonet-type mounting apertures which are adapted to receive ends of fiber optics light cables.

U.S. Patent No. 3,733,481 discloses a fiber optics light source which includes a lamp house including a lamp, reflector and condenser aligned for focusing light into the receiving end of a fiber optics bundle and which utilizes an air impeller mounted laterally of the lamp house to direct air over the lamp for dissipating heat build-up. 1 It is also known in the art to position one end of a fiber 2 optics bundle a predetermined distance from a light source 3 forming a gap therebetween to permit the light from the light 4 source to be received by the one end of the fiber optics bundle

5 and transmitted therethrough to illuminate the fiber optics 6 bundle. Typical of such light sources are those described in 7 U.S. Patent Nos. 4,128,332 and 3,497,981.

8

9 It is also known in the art to position a filter, or the 0 like, between a high-intensity light source and the one end of 1 fiber optics bundle in order to 'control the wavelength of ligh 2 applied to one end o.f the fiber optics bundle. One such devic 13 is disclosed in U.S. Patent No. 4,236,191 wherein a fiber opti 14 bundle is positioned at a predetermined space from a light

15 r source, and a color wheel having a plurality of transparent 1

16 ! colored areas formed of glass and suitable plastic mounted for rotation proximate the light bulb and intermediate the light ιa ! source and the end of the fiber optics bundle. The light

1-' transmitted by the fiber optics bundle is utilized to illumina a musical instrument such as a guitar.

Λ-i U.S. Patent No. 3,536,908 discloses a fiber optics lighti system which utilizes a rotatable turntable member which is divided into light-transmitting radial segments, and the

25 segments are rotated intermediate the gap between the end of a 26 light source and the end of a fiber optics bundle. The rate o 27 rotation of the rotatable member interposed between the light 28 t.:

-4- source and the ends of fiber optics bundles, which are disclosed in U.S. Patent Nos. 4,236,191 and 3,536,908, is at a very low speed and is intended to present different colors which are

4 visually observable to a viewer. 5 6 In addition to the method described above, hot mirrors, 7 which absorb infrared and thus become hot, while reflecting 8 visible light, have been used to reduce heat and temperature at g the light-receiving end of the light conduit, but hot mirrors do

10 not absorb enough of the infrared radaition to prevent damage to

1 ^"I the light conduit, and hot mirrors are expensive. Cold mirrors, which reflect visible light while allowing infrared radiation to pass through, still reflect too much infrared radiation, causing damage to the light conduit.

16 The high-intensity light source for a fiber optics 17 illumination system has a large number of advantages over the 18 known prior art light sources. None of the known prior art 19 systems disclose, suggest, or teach the use of an impeller or 20 fan located in the gap between a light source and one end of the 21 fiber optics bundle. The impeller displaces air heated by the 22 light source located in the vicinity of the reflector, light 23 source, and one end of the fiber optics bundle along a generally 24 axial path towards the end of the fiber optics bundle and away 25 from the light source. The air flow produces a negative ^{■ '}■ 26 pressure in the vicinity of the impeller, reflector, and light 27 source which causes cooling of the end of the fiber optics. 28

None of the fiber optics light sources disclosed in U.S. Patent Nos. 3,775,606 and 3,733,481 disclose a cooling fan having its blades disposed between the light source and the fiber optic.

The use of a rotatable color wheel is disclosed in U.S. Patent Nos. 4,236,191 and 3,536,908 wherein a color wheel is positioned in the gap between the light source and the end of the fiber optic to filter the light, and thereby change the color of the light.

Two fundamentally different type of fiber optics, or light conduits, are employed in the art. First, and probably most widely recognized, is a fiber optic formed from carefully extruded glass filaments, or fibers, which are very fine. A plurality of such fibers are bound together into a bundle, whic is glued together with an adhesive such as epoxy. Fiber optics of this type are commonly used for transmitting communications, as well as for simple transmission of light for lighting purposes. Glass fiber optics are not well suited for general illumination systems disclosed in the prior art. Glass fiber optics are quite fragile and each fiber must be coated with a protective coating , typically a flourine-basεd polymer, to protect the glass fiber. The bundle of a plurality of fiber optics must then be encased in a larger sheath. As noted, the individual fibers are then glued together with an adhesive,

1 custo arily epoxy. In high intensity illumination systems 2 according to the prior art, the bundle of fiber optics becomes too hot for the epoxy, which breaks down chemically. The epoxy

4 then loses its adhesive properties, causing the bundle of fiber 5 optics to lose its cohesiveness, and the individual fibers tend 6 to separate from one another, reducing the efficiency of light 7 transfer to the fiber optic bundle. Furthermore, a chemical 8 product of reaction of the decompositiion of many types of 9 epoxies used in glass fiber optics is a flourine-based acid, 0 which eats into the glass fibers and ruins them. In addition, 1 as the' epoxy deteriorates and decomposes, it undergoes a color change from .substantially transparent to amber, to yellow,^" to brown. This color shift causes the fiber optic bundle to absorb

14 mere infrared radiation, which is converted to additional heat, 15 accelerating the deterioration and decomposition of the εpxoy 16 exponentially. General use epoxies decompose when subjected to temperatures of about 700 degrees F. or more. A few specialty epoxies, which are quite expensive, may tolerate temperatures of

^*> o about 1,200 degrees F. before decomposing. The quantity of

20 heat that the epoxy is exposed^' to is also a critical factor in the chemical breakdown of the epoxy. Prior art illumination

22 systems that attempt to employ high intensity light sources 23 cannot keep the temperature and heat low enough to prevent 24 decomposition of the epoxy. 25 25 The second type of optic fiber is a polymerized plastic 27 type substance, which may be any of a number of chemical 28 1 co positions that are well known in the art. Such compounds ar 2 customarily formed i_ι situ in some type of vessel, such as a length of tubing. The resulting product is a semi-solid plasti type material, which may be roughly transparent or translucent. It may be more or less flexible. It is customarily available i sizes ranging from about 3/16 inch to about 5/8 inch in diamete and in various lengths. The material is not, however, a fiber

0 in any normal sense of the word. It is rather a semi-solid o continuously linked polymer. Most such plastic light conduits 0 melt at temperatures of about 180 degrees F. At temperatures 1 well below the melting point, such plastic light conduits oxidize and chemically deteriorate, with readily apparent*¹ color shift from translucent to amber, to yellow, to brown. Naturally, this color shift caused by the chemical deterioratio reduces the amount of light that the light conduit will conduc and reduces the color temperature and changes the color of the light trasnraitted through the light conduit, all of which redu

^~ 9- !ι the utility of the illumination system and increase maintenanc

^"1 Q I costs. Additionally, the now-darker light conduit absorbs mor

20 infrared radiation, which is converted to heat, accelerating t 21 deterioration of the light conduit exponentially. 22

No generic name for such plastic based polymer light conduits is known to applicant. In this patent application, t

25 term "light conduit" shall be a generic term that refers to an 26 type of material designed to transmit, or conduct light throug 27 it, including glass fiber optic bundles, polymerized plastics, 28 or other material that is or may become known.

In the prior art systems, including the patents described hereinabove, the heat from the light source makes the end of the fiber optic extremely hot, which severely reduces the life of the fiber optic. In addition, if the end of the fiber optics bundle is heated to a very high temperature, the epoxy used in the glass fibers may break down, reducing the amount of light entering into the fiber optics bundle.

It is becoming increasingly desirable in the art to use plastic fiber optics bundles in a wide variety of applications. Plastic- fiber optics are even more susceptible to heat damage than bundles of glass fibers and, because of this heat damage, the number of applications in which the plastic light conduit can be used is limited primarily to applications requiring small amounts of light. Plastic or polymerized fiber optics, or light conduits, deteriorate quickly when exposed to heat and oxygen. They become quite brittle and turn brown. The brown color of the light receiving end discolors the light transmitted through the fiber optic in an unpleasing manner, and causes the fiber optic to absorb more heat and to convert more light to heat, both of which accelerate the deterioration of the fiber optic.

Many techniques have been used to reduce the amount of heat at the light receiving end of the fiber optics bundle, including filters, fans, cold mirrors, and the like, as noted above. Such systems have achieved only limited success in keeping the light receiving end of the fiber optic cool, and they reduce the amount of light received by the fiber optic.

Consequently, most fiber optic illumination systems of the prior art must use a lamp or other light source that consumes less than about 150 watts of electricity. Even ordinary household incandescent 100 watt light bulbs produce too much heat for many prior art light conduit illumination systems. A few prior art illumination systems can use light sources that consume up to about 120 - 130 watts of electricity, but then the •"light conduit must be placed .relatively distant from the light source and cannot be placed near the focal point of any focusin reflector, or lens, without causing the light conduit to deteriorate rapidly from the heat.

It is important to recognize that although the prior art discloses fiber optic illumination systems, these are low intensity illumination systems that cannot transmit very much light, whereas the present invention is directed to an illumination system that can easily employ high intensity light sources consuming 500 watts of electricity or more. Even using dramatically more powerful lamps, the present invention also permits placement of the light conduit at the focal point of a focusing reflector or lens.

Demand for lighting systems employing light conduits is

10

1 rapidly expanding in many applications, including: use in wet 2 places where electricity is not safe, such as in swimming pools use in places requiring indirect lighting, such as instrument panels; use in places where the heat of incandescant light is o not acceptable; use in places that are small and difficult to

6 direct light into; and many others.

7

8 It is also known in the art to utilize a fiber optics

9 illumination system for a wide variety of applications, such as 0 a pendulum light source as disclosed in U.S. Patent No. 1 3,389,247; a fiber optics light source described in U.S. Patent

12 No. 3,382,353; an illumination device for a sign, as disclosed

13 in U.S. Patent No. 3,208,174; a self-luminous sign, as disclose in U.S. Patent No. 3,038,271; and illuminated signs, as r. disclosed in U.S. Patent Nos. 2,173,371 and 2,058,900.

16

Therefore a need exists for a high intensity light source for a light conduit illumination system that will provide

19 brighter lighting from a light conduit or conduits, while 20 preventing deterioration of the light conduit resulting from 21 excess exposure to heat and oxygen. 22 23 24 25 26 27 28 SUMMARY OF THE INVENTION

This invention relates to a new, novel and improved high

5 intensity light source for a fiber optics illumination system. 6 In the preferred embodiment, the high-intensity light source includes a high intensity incandescent halogen lamp, although any suitable light source may be used, and a reflector for o directing light from the high-intensity light source along a . 0 predetermined path. The fiber optics illumination system 1 includes means adapted to position one- end of a fiber optics 2 illumination conduit along the predetermine^*d path at a spaced

* 3 distance from the high-intensity light source, defining a gap 4 therebetween. An axial flow, propeller-type impeller having a 5 plurality of vanes extending radially therefrom at a selected 6 pitch, that is, a fan is located along the predetermined path. 7 The fan is positioned relative to the gap such that when the fa 8 is rotated, the blades are transported through the gap and the 9 light is directed along the predetermined path. The fan is 0 capable of being rotated at a rate of rotation at least equal t a predetermined rate so that the interception of the light by ? the fan blades is visibly imperceptible to a user, while the fa simultaneously displaces air heated by the light source located in the vicinity of the reflector, light source, and positioning means, along a generally axial path towards the positioning 6 means and away from the light source to form a negative pressur in the vicinity of the fan, the reflector, and the light source 3 -12-

1 This negative pressure causes ambient air located in other than 2 the vicinity of the reflector, light source, and impeller to be 3 drawn into the negative pressure area, whereupon the air is 4 heated and then displaced and exhausted from the apparatus by 5 the rotating cooling fan. The fiber optics illumination system 6 naturlly includes an electric motor coupled to the fan to rotate 7 it at a predetermined rate. The fan may advantageously be made 8 of a transparent material, such as a transparent plastic. The 9 color of the fan does not have much effect on the illumination 10 from the light conduit — even a black fan will not noticably 11 reduce the light in the light conduit. A transparent fan will,

1 however, absorb less infrared radiation, will therefore stay 13 cooler, and will have a longer life. i _

18 19 20 21 22 23 24 25 26 27 28 BRIEF DESCRIPTION OF THE DRAWINGS

Referring particularly to the drawings for the purpose of illustration only and not for limitation, there is illustrated:

Figure 1 is a schematic representation, partially in section, of a high-intensity light source for a light conduit illumination system according to the present invention.

Figure 2 is a schematic representation, partially in section, of a high-intensity light source mounted on an insulated bracket and illustrating the negative pressure area between the cooling fan and the light source;

Figure 3 is a perspective view, partially in section, showing the relationship between the lamp, the cooling fan, an the light-receiving end of the light conduit.

Figure 4 is a schematic representation, partially in section, illustrating a high-intensity light source for a ligh conduit illumination system according to the present invention and having a rotatable color wheel located between the cooling fan and the light-receiving end of the light conduit.

Figure 5 is a plan view of a color wheel according to the present invention.

-14-

1 Figure 6 is a plan view, partially in section, of the other

2 end of a light conduit utilizing a reflective mirror to reflect

3 the light from one end thereof back into the light conduit.

4

5 Figure 7 is a diagrammatic representation of one end of a

6 light conduit having a color gel, or other light filter, located

7 at the end thereof to determine the wavelength, and hence the

8 coior, of the light transmitted by the light conduit.

9

10 Figure 8 is a pictorial representation of a light conduit

1 having a plurality of colored gels, or other light filters

^~ interposed between sections of the light oonduit to change the ^* color of the light in the different sections of the light

1 -- conduit.

Figure 9 is a diagrammatic representation of a display sign

17 formed by a light conduit that leaks light out of its 18 sidewalls. 19 20 Figure 10 is a display device utilizing the teachings of 21 the present invention wherein the light-transmitting ends of a o o plurality of light conduits are formed into a pattern to form a dollar sign.

24 25 Figure 11 is a perspective view of a swimming pool lighted 26 according to the present invention. 27 28 1 Figure 12 is a sectional elevation of a fluid-tight 2 coupling member for a light conduit, according to the present 3 invention. 4 5 Figures 13A, 13B, and 13C illustrate that the angle of the 6 cone of light transmitted through the fluid-tight coupling is 7 determined by the distance between the light-transmitting end o 8 the light conduit and the lens of the fluid-tight coupling. 9 10 Figure 14 is a sectional elevation of a fluid-tight 11 co'upling member according to the present invention.

19

__.._. Figure 15 is a top plan view of a high-intensity light source for a light conduit illumination system according to the present invention adapted for use with a display device. iO

Figure 16 is a top plan view of a high-intensity light source for a light conduit illumination system adapted for use with other devices, such as medical devices.

20 i,

21 Figure 17 is a plan view, partially in section, of another

^*—' ,1 -embodiment of a high intensity light source for a light conduit illumination system according to the present invention.

Figure 18 is a section taken along lines 18 -18 of Figure

26 17. o? Figure 19 is a section taken along lines 19 -19 of Figure

17 . o

Δ. Figure 20 is a section taken along lines 20 -20 of Figure

17.

0 Figure 21 is an elevation, partially in section, of a glass 7 envelope for retaining and protecting a light conduit in a high 8 intensity light source according to the present invention. 9 0 Figure 22 is an elevation, partially in section, of another embodiment of the a glass envelop and stopper according to the present invention.

Figure 23 is a schematic illustration showing the

-. _ relationship between the cooling fan, the lamp, the color wheel, 6 and the light-receiving end of a light conduit relative to the 7 focal point of the lamp and reflector, according to the present 8 invention. 9 0 Figure 24 is a perspective view of a mechanical light 1 attenuation member for controlling the amount of light received 2 by the light-receiving end of the light conduit according to the present invention. 4 5 Figure 25 is a schematic top plan view of a high intensity 6 light source for a light conduit illumination system having 7 three separate illumination systems according to the present 8 1 invention housed in one apparatus, 2 3

Figure 26 is a top plan view of an illumination system according to the present invention illustrating the ventilation ducts and their relation to the housing.

7

8

9

10

11

12

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o

o ~

23 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Figure 1 illustrates a high-intensity illumination means adapted for use in a fiber optics illumination system which includes light conduit 30 having one end 32 thereof which is adapted to receive light from high intensity light source 24. Light conduit 30 has its remote end 36 formed such that light will be transmitted through end 38 at an angle alpha.

The illumination means includes a high-intensity lamp 24, which is a quartiz halogen lamp designed to operate on twenty- 2 four volts in a preferred embodiment, and reflector _%25 for directing light from the high-intensity light source along a predetermined path from lamp 24 to the one end 32 of the fiber 5 optics bundle 30. Gap 40 is located between lamp 24 and end 22 of light conduit 30. Preferably, the end 32 of light conduit 30 is positioned at the focal point of lamp 24 in order to provide the maximum coupling efficiency between the light generated by xt.he light source 24 and the end 32 of the fiber optics bundle 30. Reflector 25 is specially designed to focus the light into a light-spot (rather than the theoretically perfect "focal points") of about five eights of. an inch in diameter, at a distance of about one and one-half inches in front of the leading edge of reflector 25, as is well known in the art. Reflectors having different diameter light spots and different focal lenghts may be selected and matched to a particular lighting system, which is well within the skill of the ordinary

1 mechanic in the art. Ideally, of course, the diameter of the 2 light spot produced by the reflector would be the same as the 3 diameter of the light conduit being used. Even so, much of the light produced by the lamp will be scattered an will not strike the light-receiving end of the light conduit.

5 7 An illumination system according to the present invention

8 may readily be adapted to use any light-focusing system, such o convex lenses, or a condensor lens in cooperation with focusin

10 lens or lenses. It has been found, however, that such lenses ι i are not necessary and that use of a properly designed reflecto is the most efficacious method of focusing the light. This is^{^} true because a minimum of approximately eight per cent of incident light is reflected at the interface between two media, such as glass and air, even when the angle of incidence is .G ninety degrees. Thus, even a simple single element lens transmitts only about eighty-four per cent of the light striki it at ninety degrees. Clearly, lens focusing systems,

I O especially those employing more than one glass element, substantially reduce the light available to the light conduit.

22 Throughout this patent application, one end of the light conduit is referred to as the "light-receiving end" and the other end is referred to as the "light-transmitting end" when 5 is necessary to distinguish between the two ends. There is no 26 structual difference between the two ends, and either may 27 perform either the function of light-receiving or the function 23 l eff ctiveness, but one end must ther end remote therefrom.

ioned relative to a housing n aperture 28 located therein e end 32 of the fiber optics he predetermined path at a space y light source 24 defining a gap

urality of radially extending redetermined path. In the ler 42 is an axial flow, a plurality of vanes 44 extendin ected pitch. The impeller 42 is 40 such that when the impeller 42 ng vanes 44 are transported t the light being directed along peller 42 is capable of being t least equal to a predetermined s that rate wherein the e plurality of-vanes 44 is but wherein the rotating air heated by the light source he reflector 25 and light source ath is a generally axial path he heated air is directed away

1 from the light source 24 to form a negative pressure in the

2 vicinity of the impeller 44. This is explained in greater 3 detail in Figure 2. The ambient air located in the vicinity of

4 other than the reflector 25, light source 24, and impeller 44 is 5 drawn into the negative pressure area, heated by the light 6 source 24, and then displaced in response to rotation of the 7 impeller 44. 8 9 In Figure 1, the impeller 42 is rotated by a rotating 0 means, such as motor 48, at a rate of rotation which is at least 1 equal to the predetermined rate. The motor 48 and the light ! source 24 are operatively coupled via lead 50 to a power source 52.

Figure 2 is an alternate embodiment of a side view wherein 0 the impeller is rotated such that the blades thereof intercept the light passing from the light source to the fiber optics bundle. In the embodiment of Figure 2, a high-intensity light

1 c, source is operatively coupled to light source bracket 66 by a Teflon insulator 68. The Teflon insulator is preferably formed of FΞ? Teflon, which is well known in the art. The reflector 62 li reflects the light generated from the high-intensity light source 60 when energized by electrical power applied to terminal 70 thereof. The light then heats the air located in the d o vicinity of the reflector illustrated by 92, which is then 26 displaced by rotation of the impeller having a hub 76, radially 27 extending vanes 73, which are curved so as to displace the air 28 1 fro the vicinity of the reflector 62 towards the end 83 of

2 fiber optics conduit 84. The air flows axially, as illustrated

3 by arrows 82. By rotating the impeller at a speed of

4 approximately 500 RPM or higher, the curved vanes 78 displace

5 the air along the lines as shown by arrows 82.

6

7 Concurrently, the impeller is rotated such that hub 76

3 having a plurality of radially extending vanes 78 therefrom

9 displaces the heated air in the vicinity of the area 92 along 0 the axial paths shown by arrows 82, resulting in a negative 1 pressure in the vicinity of the^• impeller, light source 60, and 2 reflector 62, which negative pressure is illustrated by arrows 3 94. The negative pressure 94 draws ambient air from the 4 vicinity other than the location 92 having the heated air into 5 the negative back pressure, the ambient air flow being shown by

16 arrows 100. The process is continually repeated, which results

17 in the high-intensity lamp 60 operating at or near its desired

13 operating temperature and with the impeller rotating the

19 plurality of vanes 78 at a sufficient rate of rotation to

20 displace the air at a high enough rate such that when the air is

21 received by the end 83 of fiber optics conduit 84, the

22 temperature of the air is low, thereby avoiding destruction of

23 the end 88 of the fiber optics 84. The vanes 78 intercept the

24 light from the light source 60 which traverses along the o^ predetermined path along one end 88 of the fiber optics 8 . The

26 light received by the one end 88 and transmitted by the fiber ootics bundle or illumination conduit 84 emanates out of end 90

28 as illustrated in Figure 2.

Figure 3 illustrates the preferred embodiment of the high- intensity light source, which includes a high-intensity light source 112, which may be a halogen lamp, and a parabolic-shaped reflector 110 which defines a discrete edge 114. There is a slight distance between the end of reflector edge 114 and the impeller 116. The impeller 116 includes a hub 118 and a plurality of radially extending blades 120 which have a predetermined pitch. The pitch illustrated in Figure 3 is such that the blades displace the air from the vicinity of the reflector 110 and axially towards the one end 128 δf fiber. optics bundle 126.

Figure 4 illustrates a variation of the high-intensity light source illustrated in Figure 1 with the addition of a light-attenuating member, such as a rotatable disc 130 having color gels located in the end thereof. The light-attenuating member is positioned along the predetermined path intermediate the impeller 42 such that the plurality of rotating vanes 44 will rotate without hitting the light-attenuating member. The light traversing along the predetermined path is attenuated by the filter member such that the wavelength of the lights ultimately applied to the one end 32 of the fiber optics bundle 30 can be selected. In the embodiment illustrated in Figure 4, the rotatable member 130 includes a hub 135 which has an annular-shaped outer rim 134 formed thereon. The extending

1 outer rim includes a plurality of air-bleeding holes 142 and a 2 plurality of apεrtured areas 138 which are adapted to receive 3 color gels 140. A motor 148 is positioned to rotate the 4 rotatable member 130 in such a manner that the outer edge 5 thereof including the color gels 140 are selectively passed 6 through the light path and intermediate the light source 24 and 7 the one end 32 of the fiber optics bundle 30. 8 9 Figure 5 shows the rotatable disc member 130 in a front

10 view illustrating the relative positions between the hub 135,

I ^"1 the extending outer rim 134, the apertures 133, and the

10 locations of the gels 140. In the embodiment illustrated in

Figure 5, the gels are formed into an arcuate shape so as to ensure that the color gel is positioned between the light source 24 and the end 32 of a fiber optics bundle 30 for a controlled sector angle of the disc rotation. The disc 130 is rotated at a relatively low rate of rotation, such as about 2 RPM.

18 19 When a light conduit is used for signs or other light 20 displays, such as the sign illustrated in Figure 9, it is 21 necessary that light radiate from the sidewalls of the light 22 conduit. Some amount of light leaks from the sidewalls of all 3 light conduits. In the case of signs, however, clearly the sign 2 will be brighter, easier to see, and consequently more desirable if most or all the light directed into the light conduit leaks

26 out the sidewalls. Glass fiber optics do not leak enough light 27 from their sidewalls to be useful for signs or other lighted 28 1 i displays that rely on sidewall lighting. Plastic-type polymer based light conduits do leak enough light from their sidewalls to be useful for such signs and lighted displays.

The amount of light to be retained within the fiber optics

6 light conduit can be controlled in a number of ways, one of

7 which is illustrated in Figure 6. In Figure 6, light-

8 transmitting end 150 of a fiber optics bundle transmits light

9 therefrom along an angle alpha, as illustrated by lines 152. A

10 reflective member having a base 156 and a mirror reflective

11 surface 158 is spaced from light-transmitting end 150 at a i o predetermined distance to reflect the light received from the iO end thereof back into the light conduit, simulating a, light source, with the reflected light being shown by arrows 160. By placing the mirror on light-transmitting end 150 of the light

16 conduit, the end of a sign remote from the light source is about 17 10% - 15% brighter than it otherwise would be, increasing the 18 unformity, and hence esthetic appeal of a display or sign using 19 illuminated plastic-type light conduits. Coating otherwise 20 light-transmitting end 150 of the light conduit with a white 21 substance, such as paint, increases the amount of light 22 reflected back into the light conduit even more. A colored 23 coating on the otherwise light-receiving end 150 of the light conduit reflects its color back into the light conduit, creatin

25 a colored display. The color applied to the otherwise light- 26 transmitting end of the light conduit may be the same as the 27 color of a filter at the light-transmitting end, to create a 23 nearly uniform color throughout the display, or it may be a different color.

Alternatively, a high intensity illumination system according to the present invention may be applied to each end of the light conduit, with or without a color wheel at either or both ends of the light conduit. Rotation of the color wheels may be synchronized so that the color changes from each end of the light conduit are the same through time.

Figures 7 and 8 shown alternate methods of controlling the wavelength of the light transmitted_^ by the fiber optics cable. Figure 7 illustrates a fiber optics cable 170 having a color gel 172, or other light filter, applied to the end thereof. The end with the color gel 172 can be utilized in the embodiment of Figures 1 and 3 to control the wavelength of the light being applied thereto. The low temperature located in the vicinity of the fiber optics end is such that the gel 172 will not melt.

Figure 8 illustrates the use of a fiber optics cable, or other light conduit, having a plurality of segemεnts, with adjacent segments being separated by a colored gel or other light filter. Segment 180 is separated from segment 186 by a filter or gel material 184. Segment 186 is separated from segment 190 by second color gel 183. Likewise, segment 190 is separated from segment 194 by color gel 192. By selecting the wavelengths of light to be passed through the different .gels, the wavelengths of light in each of the sections and the color of the light emanating therefrom can be controlled. Naturally, the color effect is cumulative as the light traverses lignt conduit 195, because once the light passes through one filter, the light is no longer white, but takes on the color of the filter, so the next filter will not produce the- same color it . would produce if white light had passed through it. That is, if the first filter or color gel 184 is green, segment 186 will glow with green light. Then if color gel 183 is yellow, segment 190 will glow blue, and so forth according to principles of light color .that a-re well known in the art. Naturally, if light is is transmitted through light conduit 195 in the opposite direction, and the same filters or color gels are in place, an entirely different set of colors will be generated, also according to well known principles of light color. (The passage of light through the fiber optics 195 is illustrated by arrows 1S5.) Methods of splicing plastic-type light conduit and of attaching color filters to it are well known in the art.

Figures 9 and 10 illustrate a display device utilizing the teachings of the present invention. Figure 9 illustrates a display sign wherein the sign 200 has a fiber optics conduit 203 formed therein into a predetermined graphic de-sign. One end of the fiber optics 208 illustrated by end 206, is operatively coupled to a high-intensity light source 202. The high- intensity light source 202 has power applied thereto through a power source 204. As illustrated in Figure 9, the fiber optics

1 conduit 208 is formed into a predetermined path to form letters.

2 The light emanating through the segments of the fiber optics

3 bundle illuminates to give the appearance of a neon sign. The

4 color of the light emanating therefrom can be controlled as

5 described in connection with FIGS. 4, 5, 7 and 8 above.

6

7 Figure 10 illustrates an alternate embodiment of a display

8 device wherein the fiber optics cable is located within the

9 display 224 such that bundles of fiber optics, illustrated by 0 bundles 226, are formed into a graphic image such that light 1 emanates through the ends thereof, such as ends 230. The fiber 2 optics 220 would be operatively connected to a high-intensity

13 light source of the present invention in the same manner as

14 discussed in connection with Figure 9 hereof.

15

16 Figure 11 illustrates an alternate application utilizing

17 the teachings of the present invention. Figure 11 shows a spa

18 238 having an inner wall 240 which holds fluid therein, such as

^~ Q water. A high-intensity light source 242 which is energized from a power source^' 244 produces a high-intensity light which is

21 applied to one end of the fiber optics bundle 246. The fiber 22 optics bundle has its other end thereof divided into a plurality 23 of smaller fiber optics bundles, illustrated by fiber optics 24 bundles 248, 250, 252, 254, 256 and 258, which terminate in 25 planar light-transmitting members 260, 262, 264, 266, 268 and 26 270, respectively. The specific construction of the fluid-tight 27 coupling member is illustrated in greater detail in connection 23 1 with the discussion of Figure 12. 2 3 In use, the fluid-tight coupling member is adapted to 4 receive the other end of a -fiber optics cable such that the 5 light which emanates from the end of the cable is transmitted 6 through the planar members 260, 262, 264, 266, 268, 270 to 7 illuminate the interior of the spa 238. This provides a 3 pleasing illumination effect. Also, by use of the light- o attenuating member described in connection with FIGS. 4, 5, and 0 7 herein, the color of the light can be controlled to provide a

^"i 1 very pleasing effect.

α. The fluid-tight coupling member for the fiber optics conduit is illustrated in greater detail in Figure 12. Figure 12 illustrates a fluid-tight coupling member which comprises an elongated cylindrical-shaped member 270 having a hollowed-out central area 278. The cylindrical-shaped member 270 terminates in a relatively planar member or light-transmitting member 260, which is sealingly attached to the one end of the elongated cylindrical-shaped member 270. The planar member is capable of transmitting light from the interior of the elongated cylindrical-shaped member 270 to the other side thereof. The elongated cylindrical-shaped member 270 has its exterior surfac 272 threaded and has its other end thereof terminating in the elongated boss 276. The exterior dimension of the elongated boss 276 is less than the dimension of the threaded portion 272 of the elongated cylindrical-shaped member 270.

1

2 A first connector 280 has a central portion and a larger

3 annular-shaped portion 282. The central portion includes means

4 284 for defining a hαllσwed-out central area and for providing

5 threading means which are adapted to coact with the threaded

6 members 272 on the external surface of the elongated

7 cylindrical-shaped member 270.

8

9 A planar washer member 286 is adapted to be positioned

10 between the annular-shaped outer ring 282 of the first connector

11 280 which is adapted to be urged into sealing engagement with

12 the surface of a relatively thin wall member 240 and passed

_** %

13 through an aperture formed therein. The first connecting member

14 280 is capable of being rotated in a first direction coacting

15 with the internal threads 234 formed in the interior cavity

16 thereof with the threaded members 272 formed in the exterior

17 surface of the elongated cylindrical-shaped member to form a

18 fluid-tight sealing engagement between the annular-shaped outer

19 ring of the first connecting member 280, the washer 236, the

20 thin wall 240, and the flat, light-transmitting member 260.

21

22 A second connecting means 290 includes means for defining an interior cavity thereof 292 which includes means for defining

24 threaded members at one end of the second connecting means and 25 means for defining an end cap 294 at the other thereof, which 26 includes means for defining an aperture having an axis which is 27 coaxially aligned with the center of the hollowed-out central _ 28 1 area which is adapted to receive boss 276. The aperture formed 2 in cap 294 is selected to be of a dimension which is adapted to 3 receive and pass a fiber optics conduit 300 having a known 4 geometrical dimension.

6 An O-shaped ring member 296 having a geometrical dimension

7 which is substantially equal to the geometrical dimension of th

8 fiber optics conduit 300 and which is adapted to be positioned

9 therearound is positioned between the end cap 294 and the edge 0 defining the elongated boss 276 of the elongated cylindrical- 1 shaped member 270. The second connecting member 290, when 2 positioned over the end of the elongated cylindrical-shaped 3 member 270 and when threaded in a predetermined direction 4 thereagainst, causes the end cap 294 to be urged into the O-ri 5 member 296, urging the O-ring member 296 into sealing engageme 16 with the other end of the elongated cylindrical-shaped member 17 270 forming a fluid-tight seal therebetween. The fiber optics 13 conduit 300 is responsive to a light illumination being applie 19 thereto at one end thereof and to transmit light therethrough 20 the other end of the fiber optics conduit 302, which is locate 21 j near the flat, light-transmitting member 260. The light passe 22 out of the end of fiber optics conduit 302, through the flat, 23 light-transmitting member 260, and is then transmitted on the d <± other side of the thin wall 240. 25 26 Figures 13A, 13B and 13C pictorially illustrate the 27 relationship between the end of fiber optics conduit 300 23 1 relative to the flat, planar, light-transmitting surface 260. 2 As illustrated in Figure 13A, if the end 302 of fiber optics 3 bundle 300 is located very near to or contiguous with planar 4 member 260, the light passes therethrough and forms a light 5 having a diameter illustrated by dashed lines 310. Figure 133 6 illustrates that when the end 302 is positioned a short distance 7 from the flat, light-transmitting member 260, which results in 8 an increased angle of light thereby increasing the amount of 9 light passing through the flat, light transmitted therethrough. 10 If the fiber optics 300 is positioned such that end 302 is moved further remotely from the flat,^' light-transmitting surface 260, a greater degree and angle of light passes through the ffat,

-_. o i light-transmitting member, as illustrated by dashed lines 314.

Figure 14 illustrates an alternate embodiment of a fluid- iU tight coupling member which is adapted to be utilized in a fluid environment. This is a variation of the device of Figure 12,

18 which has application for use with a standard illumination means 19 or a very wide bundle of fiber optics. The fluid-tight coupling 20 member includes a fiat, light-transmitting member 400 which has 21 an elongated central area 402 extending therefrom which defines 22 a hollowed-out central area 406 in the center thereof. A thin 23 wall 410 of a fluid environment, such as the wall of a swimming 24 pool, is formed with an aperture therein which is adapted to 25 pass the elongated central member 402 therethrough, causing the 26 ridge of the flat, light-transmitting member 400 to be brought 27 into sealing engagement with one side of the thin wall 410. 28 The elongated central member has its outer periphery thereof threaded with threaded members 404. The connecting member 414 having an annular-shaped ridge member 420 and having threaded members located in the interior thereof is mounted relative to the elongated central member 402 so as to coact with the threaded members 404 formed around the periphery thereof. When the first connecting member 414 is threaded towards the flat, planar member 400, it is brought into sealing engagement with

9 i the annular-shaped ring member or washer 412. By threading the

10 first connecting member 414 in a direction so as to urge the

11 washer 412 against the other side of the wall 410, a fluid-tight ^*ι o ^seal is formed between the flat, light-transmitting member 400, the thin wall 410, and the washer 412.

15 In this embodiment, a standard light bulb, illustrated by 16 light bulb 430 and a light socket '432, can be positioned into the hollowed-out area 406. In the event the light bulb 430

18 needs to be serviced, the light bulb can be withdrawn from the 19 area 406, replaced or serviced, and then reinserted into 20 position. This avoids the necessity of removing a front light- 21 transmitting member 400, which is typical in certain swimming 22 pool or other applications.

Figure 15 illustrates a high-intensity light source having

25 a housing 500 which encloses the entire system. Step-down 25 transformer 502 is energized from a 110-volt, 60-hertz, AC 27 source via lead 504 and plug 506. Step-down transformer 502 23

r

e

g

y

1 illumination means directs the light from high-intensity light 2 source 612 along a predetermined path onto the end 630 of a 3 fiber optics conduit 634. A coupling means 632 operatively 4 connects the one end 630 and holds the same in a predetermined 5 position relative to the light source 612. In the preferred 6 embodiment, the end 630 is positioned at the focal point of the high-intensity light source 612, which is developed by the reflector 610. An impeller, in the form of a rotatable fan-type

9 impeller 616 having a plurality of radially extending vanes 0 extεnding therefrom and having a predetermined pitch is 1 positioned to intercept the light as it passes from the light

12 source 612 onto the end 630 of the fiber optics conduit 634.

- -, ^'!! The turbulence and other effects as described in connection with

!i Figure 2 provide the means for utilizing very high-temperature and very high-intensity lamps which are required in certain

-^LU !l medical applications. The fan-type impeller 616 is driven by a motor 618 which is energized via lead 620 electrically connected to plug 606.

Figure 17 illustrates a preferred embodiment of the illumination system of the present invention including cooling duct 700 for exhausting air from housing 702 of the illuminatior system. Cooling duct inlet 704 has an inside diameter that matches the outer diameter of fan blade 42, which is located perpendicular to the orientation of cooling duct air inlet 704 of cooling duct 700 and is located at the terminal edge of cooling duct inlet 704. Cooling duct 700 turns approximately

ninεty degrees at elbow 708, then tapers smoothly to exhaust

2 port 710. Cooling duct 700 constructed in the configuration

3 shown in Figure 17 conserves space within housing 702. More importantly, cooling duct 700 directs heated cooling air away

5 from light conduit 30, preventing the build-up of heat that

6 might result from having a cooling duct that runs parallel to

7 the light conduit. As illustrated in Figure 17, air flowing

8 through cooling duct 700 travels almost perpendicular to light

9 conduit 30, as well as striking light-transmitting end 32 0 directly, providing efficient removal of heat in the vicinity of 1 light conduit 30. It is not necessary that cooling duct 700 2' have a 90. degree elbow. It is only important that light conduit 3 30 can penetrate elbow 708 and be retained within cooling duct 4 700 without being parallel to it. Following the flow of air 5 through cooling duct 700, after the duct passes elbow 708, 16 cooling duct 700 tapers throughout its length until cooling duct 7 700 terminates in exhaust port 710, in sidewall 26 of housing 8 702. 9 20 Housing air inlet 712, whose diameter is at least equal to 21 the diameter of exhaust port 710, provides a ready path for 22 outside ambient air to flow to fan blade 42, insuring an

P. -. adequate supply of cooling air for flowing through the interior

24 of housing 702 and through cooling duct 700 at all times. 25 Housing air inlet 712 may be located at any convenient place on 26 a sidewall or the top or bottom of housing 702. In the 27 preferred embodiment illustrated in Figures 17 and 26, housing 23 1 air inlet 712 is located in the same sidεwall as exhaust port 2 710, facilitating bundling and running lenthy ventilation ducts from both openings in housing 702.

The cooling ventilation system described herein protects

6 the light conduit in two ways. First, the cooling system 7 exhausts hot air from the housing, preventing the build-up of

^■heat within the housing. Cooling duct 700 and fan 42 cooperate

9 to insure that the hεat dεveloped by lamp 24 is exhausted from 0 housing 702, in contrast to prior art systems in which it air 1 circulation for cooling does not so directly and effεctivεly 2 remove heat from the housing. Second, the cooling system

_* _ 13 according to the present invention maintains a high level of turbulence on the end of glass envelope 716, and the length of glass envelope 716, which prevents build-up of heat on glass

ID envelope 716. The tapering of cooling duct 700 causes the l'⁷ velocity of the air in duct 700 to increase throughout the lεngth of duct 700, due to operation of the gas laws, which

19 further increases turbulence around glass envelope 716. An 2 illumination system according to thε prεsent invention having 21 cooling duct 700 as illustrated in Figure 17 is thε best mode of 22 practicing the present invention now known to the inventor.

Prior art ventilation systems typically move air in such a

0 - manner that a substantially laminar flow of air surrounds the

26 light-receiving end of the light conduit, which allows excessive 27 heat to build-up on the light-receiving end of the light 23 conduit, even if the ventilation system is otherwise adequate for removing an adequate amount of heat.

Heat build-up in cricital areas of housing 702 can be controlled by applying a material that reflects infrared radiation, visible light, and ultraviolet light to selected portions of the interior of housing 702. In the actual reduction to practice of the prεsent invention by thε inventor, it has bεεn found that a strip of rεflectivε aluminium foil having a paper backing (well known in the art) applied to top half 703 of housing 702 by conventional adhesive or other means directly above lamp 24 and reflector 25, and applied, across the , _. width of housing 702 prevents any distorition of a plastic housing that might occur from radiated or convected hεat from lamp 24. Reflective foil 715 (Figures 18, 19, and 20) is attached to top half 703 of housing 702, permitting housing to be more compact because top half 703 can be physically closer t lamp 24 and reflector 25. Such rεflεctive foil, or other reflectivε means, may be advantageously applied to any other ho spots found in a high intensity illumination system according t the present invention.

Referring to Figure 26, Exhaust ventilation duct 709, having a tapered insertion end, is inserted into exhaust port 710, and ventilation inlet duct 713, having a tapered insertion end, is inserted into housing air inlet 712, providing means fo a complete circuit for ventilation air. Ventilation ducts 709, 712 may be as long as necessary to insure that adequate ambient air of suitable low temperatures is readily available in sufficient quantities. In some applications, for example, it may be desirablε to bury thε illumination system in the ground (providing a manhole-type cover for maintenance access) that do net permit the free flow of air. Ventilation ducts 709, 712 can then be run to a place that free flowing air is available. Ventilation ducts 709, 712 forty feet in length and more have been used sucessfully with the prεsεnt invεntion as disclosed herein.

The apparatus of Figure 17 includes other elements of the illumination system accordng to the present invention, including a power supply, which conveniently may be transformer 52. In the preferred embodiment disclosed herein, transformer 52 is a step-down transformer that converts standard 115 volt power to 24 volts to illuminate lamp 24. Lamp 24 may have a voltage rating of 17 volts and a transformεr producing 17 volts may bε used. It has been found, however, that a 24 volt power supply produces a whiter light from lamp 24 than 17 volts does. hen supplied with 24 volts, such a lamp consumes approximately 200 watts of electrical power. If desirable, lamps consuming up to about 500 watts of electricity or more can be employed in thε present invention without adverslεy a-ffecting light conduit 30.

Transformer 52 may bε replaced by any suitable electrical power supply capabable of meeting the power needs of lamp 24, such as, for example, a solid state power supply (not shown) . A solid state power supply would be morε compact than transformer 52, permitting use of a smaller housing.

Cooling fan 42 is driven by electric motor 48, which rotates cooling fan 42 at a rate determinεd by the design of electric motor 48, and may conveniεntly bε any spεed greater than about 500 RPM, although in a prefeffed embodimεnt, the rate of rotation is about 3,000 RPM.

Color wheel 540 is disposed between fan 42 and light- receiving end.32 of light conduit 30 so that color wheel 540 is cooled by air from fan 42, while at the same time coloring thε light rεceived by light conduit 30 in order to provide pleasing colors and changes of colors of the light transmitted by light conduit 30. Color wheel 540 is rotated by motor 542 at a rate

of about 2 RPM. Naturally thε rate of rotation of color wheel 540 may be adjusted by selecting a motor having a different rate of rotation, or by using a gear reduction system having different ratios than the gear reduction system employed in color wheel 540 drive motor 542.

Color wheel 540 and color wheel drive motor 542 are off-set from reflector 25 so that only a band along the outer circumfrence of color wheel 540, having the same width as the diameter of light conduit 30 being used in a specific application passes by light-receiving end 32 of light conduit

30. That is, only thε radially outermost portion of color wheel 540 overlaps thε linε of sight from lamp 24 to light-receiving end 32 of light conduit 30, and ovεrlap εntεnds only εnough so that color whεel 540 filters (and colors) most of the light striking light-receiving end 32 of light conduit 30. This arrangement of the parts provides the least interference with the flow of cooling air through cooling duct 700. Thus, an illumination system according to the present invention having a color wheel also enjoys the substantial benefits of the lower operating temperatures inside the housing that are conferred by the cooling system described above.

Fan 42 is likewise off-set from lamp 24, so that, while cooling fan 42 is aligned with cooling duct inlet 704, as described above, only the outermost portion of the circumfrεncε of cooling fan 42 blades pass between lamp 24 and light- receiving end 32 of light conduit 30. The radially outermost portion of most fans, including cooling fan 42, move more air than any other portion of the fan blade, and at greatεr velocity. Accordingly, the arrangement just described provides the greatest amount of thε fastest moving air that fan 42 can provide directly onto the εnd of glass εnveolpe 716, which houses light-receiving end 32 of light conduit 30. This creates and maintains continued high turbulence in the air surrounding the end of glass envεlopε 716 that is inside housing 702.

Housing 702 may conveniently be molded in one piεcε of any

convεniεnt matεrial, such as Lεxan (Registered Trademark) or other suitable material, preferably having a white color to reflεct light and furthεr rεduce hεat build-up within housing 702. As illustrated in Figure 17, housing 702 may be conveniently molded in two sections, upper section 703 o (illustrated in Figures 18, 19, and 20) and lower section 701 7 (illustrated in Figures 17 -20) , and the two sections then 8 joined together by means of adhesive or threaded fastners, as is 9 well known in the art. Fittings and support structures for 0 mounting internal components of the illumination system are 1 prεfεrrably molded into housing 702, providing for ready o assembly and easy maintenance. ,

Cradle fingers 714, molded as integral members of housing 702, firmly support and control glass εnvεlope 716, as is illustratεd in Figurεs 17, 13, 19, and 21. Two craddlε fingers 7 714 are moldεd into bottom section 701 of housing 702 and two S opposed craddle fingers 714 are molded into top section 703 of 9 housing 702. During assembly, glass envelope 716 is rested on 0 the craddle fingers in bottom section 701 of housing 702, and 1 then top section 703 is joined to bottom section 701, forming a 2 complete housing 702 and the clamping action of the opposed 3 craddle fingers 714 holds glass envelope firmly- in place. 4 5 In addition, threadεd projection 724, which conveniently 6 may be molded as an integral part of housing 702 and also may 7 have an upper sεction and a lower section, as illustratεd in 8 Figures 18, and 19, provides an additional clamping on glass envelope 716. If desired, an adhesive that will stick to glass and to plastic may bε applied to craddle finger 714 and to the interior surfaces of thrεaded projection 724.

Glass envelopε 714, which encloses light-rεceiving end 32 of light conduit 30, is sealed by the action of stoppεr 718 as is illustratεd in Figurε 21. Stopper 718 is tapperεd inwardly, in basically the shape of a flask stopper in common use in chemical laboratories. Tightening threaded cap 722, which mates with threaded projection 724 (through which glass envelope 714 I! passes, squeezes stopper 718 tightly against the inside of glass envelope 716 and against light conduit 30, thereby creating an air tight seal about light-receiving end 32 of light conduit 30. Stoppers 718 may be manufactured in a variety of sizes to 0 accomodate different diameters of glass envelopes 716 (Glass envelopes 715 according to the preferred embodiment disclosed herein are in thε shape of a glass tube) and different Q i. diameters of light conduits 30.

In some applications, such as the spa illumination system illustrated in Figure 10 and the sign illustrated in Figure 10, it is desirablε to light a plurality of light conduits from one sourcε. This objεctive is easily accomplished by the presεnt invεntion, wherein eithεr glass-type or plastic-type light conduits may be gathered into a bundle and inserted into glass envεlope 716. In such case stopper 713 may be made of

sufficienly pliable material that thε cεntral aperature therethrough conforms sealingly to the shape of the bundle. Alternatively, the stopper may include a plurality of holes

. through it, each hole receiving one or more of the individual strands of light conduit.

An alternativε embodiment of a means for sealing glass

8 envεlopε 716 is illustratεd in Figure 22, which includes O-ring o -* 730 for sealing light conduit 30 within glass envelope 716 (not 0 shown) . O-ring 730 may conveniently be sized to fit snuggly over the outside diameter of light conduit 30, and to substantially fill channel 725 on inside lip 727 of threaded cap 3 729. 4 5 The system of enclosing light-recεiving εnd 32 of -light 6 conduit 30 within an air-tight glass envelope has several significant benefits, which include: (1) End 32 of light 8 conduit 30 is protected from being pushed into fan blades 42, 9 reducing thε chances of damaging the apparatus; (2) the heat that end 32 of light conduit 30 is exposed to is reduced because the glass insulates light conduit 30 from the heat to a certain 2 extent, and the glass may be coated with a heat absorbing coating, such as a dichroic coating, to reduce the amount of heat that light conduit 30 is sujεctεd to; and (3) sealing υ light conduit 30 within glass envelopε 714 radically reducεs thε 6 amount of oxygen available to oxidizε light conduit 30. This is particularly important when a polymer based light conduit is 8

example, that it is important to distinguish the prεsent invention from other illumination systems for light conduit lighting arrangements that only invlove low light levels and do not employ high-intensity lamps. Only when one attempts to cl employ high-intensity lamps to increase the amount of light that

> i| a system can transmit does one encounter the problems that are addressed and solved, for the first time, by the presεnt invention.

26 Figure 23 schematically illustrates the spatial relationships between lamp 24, reflector 25, cooling fan 42,

23 1 color wheel 540, and light-receiving end 32 of light conduit30. 2 Dotted lines 732 illustrate the focusing of light from lamp 24 by reflector 25 into a conε (thε actual light and focusing occur in thrεε dimεnsions, while the drawing of Figurε 23 illustrates it in two dimensions) having a focal point. Thε dia εtεr of thε actual focal point or spot is a characteristic of the design of reflεctor 25 and can be adjusted to suit a particular specification, by one skilled in the art. The parts are spaced

9 from one another so that they arε all groupεd near focal point 0 734, with focal point 734 falling nearly on color wheel 540,

11 which is spaced as nearly as practical to light receiving end 32

12 of light conduit 30. This remains true for a light conduit -¹ — sealed in a glass- envelopε, as dεscribed above. Fan blade 42 is

14 located slightly closer to reflector 25 than is focal point 734.

15 The basic objective of the inventive arrangement of these parts

16 is to maximize the proportion of available light that is

17 ' received by light conduit 30, while providing adequate cooling.

18

19 Reflector 25 focuses infrared radiation, as well as visible light, and having cooling fan 42 near focal point insures that most of that infrarεd will bε converted to hεat and exhausted without reflecting throughout housing 70-2, thereby additionally reducing thε heat build-up.

25 Figure 24 illustrates a mechanical light attenuation member d o consisting of rotating shutter 740 comprising opaque spiral ask 744 permanently applied by painting, enameling, or other

23 suitable method, to circular disk 745 having shaft 742 fixedly attached thereto by conventional means. Rotating shutter 740 is located within housing 702 in the place of color wheel 540 when it is desired to control easily the amount of light available to light-receiving end 32 of light conduit 30. In use, rotating shutter 740 is rotated by turning. nob 743, which is attached to shaft 742, to cause more or lass of opaque spiral 744 to obscure light from light-receiving end 32 of light conduit 30. Shaft 742 may bε turned by hand, so that the amount of light available to the light conduit can be set to provide a desirable level of light output from light conduit 30, which can be changed on demand, or may be attached to a motor, such .as the motor that rotates the color wheel, thereby providing continuously varying levels of light output from light conduit 30 for aesthetic appeal, such as simulated strobe lights. Rotating shutter 740 doεs not change the color temperature of the light striking light-receiving end 32 of light conduit 30, which any light filter or voltage regulator operating on lamp 24 would do. Thε ability of rotating shutter 740 to reduce the amount of light transmitted through light conduit 30 without changing the color temperature is a significant advantage.

Circular disk 745 may be made of glass, plastic, or the like. Alternatively, it has been found that an opaque rotating shutter made of metal, for example, steel or similar material, cut-out in the shape of opaque mask 744 provides the desired light attenuation and does not dεteriorate in the heat.

1 Moreover, by forming a rotating shutter in the shape of the 2 spiral, adequate cooling of light-receiving end 32 of light conduit 30 is assured.

D Figure 25 illustrates a high-intensity illumination system

6 for a light conduit illumination system having three distinct 7 sets of lamps 24, rεflεctors 25, color wheels 5-.0, light

8 conduits 30, and associated hardware, including power supplies, 9 and so forth. Illumination systems such as thesε are useful 0 when it is desired to have one centrally located unit supply 1 lighting needs that requirε morε than one light conduit. Such 2 an apparatus simplifies installation and maintenance, and simplifies manufacture because only one housing 746, one cooling duct 748, and one cooling fan 750 are rεquired. Each of these threε elements must be large enough to accomodatε the -0 physical dimensions of the three lamps, reflectors, and light conduits .

Referring to Figure 16, an embodiment of the present invention suitable for medical applications is disclosed. In use, light conduit 634 may have its distal end 640 operativεly connected to a medical or other device, such as an endoscope, o: the like, represented by device 644. The embodiment of Figure 15 has wide use for medical applications and devices which require high-intensity light sources. The illumination system of Figure 16 doεs not includε a color wheel, since in medical and othεr applications is desirable to use whitε light having a

color temperature as close to daylight as possible. Thus the illumination system without a color wheel has two advantages for applications requiring white light: (1) No color filters or transparent color wheεl attεnuates the light striking light- receiving end 32 of light conduit 30; and (2) light-recεiving εnd 32 of light conduit 30 can be placed nεarer the actual focal point of the light beam from lamp 24 and reflector 25. Naturally, a cooling duct such as cooling duct 700 (Figure 17) may advantageously be used when white light is desirable, such as in the embodiment of Figure 16, permitting use of even higher intensity lamps.

In connection with the illustrations of Figures 15 and 16, the following is typical illumination for the fiber optics bundle which is fabricated with glass fiber optics. The glass fiber optics, in the preferred embodiment, can have a .66 numerical apεrtura and bε formed of 2-mil-diameter fibers. Typically, the fibers are bundled together in a protective sheath made of rubber. The terminations at the bundle ends of the fiber optics bundle are epoxied in various types of ferrules .

Typical specifications for plastic fibεr optics, or light conduits, which can be utilized in practicing this invention can havε diameters which vary from about 1/16 inch in diameter to about 5/8 of an inch in diameter or more. The plastic fiber optics, or light conduits, can have low heat resistant

temperatures from about 180 degrεεs F. to about 200 dεgrees F. Temperatures above 200 dεgrεes F. begin to break down the plastic fiber optics bundle. The plastic fiber optics can be made from various materials , such as styrene or polymethylmethacrylatε, as is wεll known in the art. The plastic fiber optics arε manufactured by use of εxtruding techniques, although other manufacturing techniques could be used. Manufacturers of plastic fibεr optics which can be utilized in practicing this invention are Polyoptical (Polyoptics) , DuPont (Crofon) , and Mitsubishi (Eska) .

Light conduits illustrated in the drawing figures may be - of εither plastic (poly erizεd) -typε, or of glass. In either case, thε light conduit is usually coated during manufacture or covered with a cladding or sheath. As illustratεd in Figurε 17, for example, light conduit 30 is enclosed in sheath 31. Sheath 31 may be any suitablε plastic material and may bε any desirεd color. Light leaks from the sidewalls of most plastic-type light conduit, in amounts that can be controlled to some extent by the exact matεrial used, the methods of manufacture used, thε type of coating usεd, and other factors that arε beyond the scope of this patent, but are wεll known in the art. It has been found that Teflon (Registered Trademark) provides a suitablε matεrial for εxtruding tubing suitable for use as sheath 31. The drawing figures may also, however, be interpreted as illustrating bundles of glass fiber optics, since each individual glass fiber must bε individually enclosed in a

-51-

1 protective sheath, but additionally a bundle of such glass fibers must also be enclosed in a larger outer sheath to protect the delicate glass fibers.

5 In applications utilizing a color wheel arrangement as a

6 light-attenuating membεr, the color wheel can be made of 7 standard acrylic or polycarbonate materials. Color gels may be 8 Roscoe Gεls which arε glued together or secured to the whεεl by 9 clips. As illustratεd in connection with Figure 5, the color 0 wheel is designεd to pεrmit air to pass through it such that when the fan blows air directly onto the color wheel, the tips of the fan blade cause the air to bε vεry turbulent near the color gel arεa, thereby cooling the same and preventing the color gels or the color whεel from deforming or melting. In typical applications, the motor driving the color wheel would rotate at about 2 RPM, but speeds of rotation at less than 2 RPM or slightly in εxcεss of 2 RPM can likewise be used without any deleterious effect to the light or the color wheel and associated light filters, whether they are color gels or other filters . d jl

2 The high-intensity light source of the present invention can be fabricatεd for above-ground use in a portable unit by utilizing a source box made of very high-impact and vεry heat- resistant plastic ma erial . Above-ground portable light sources

Λ formεd of plastic can bε utilized in portable spas and the like. The optical material utilized in such an arrangement can have a

23 onε-inch diameter and can be utilized with a color lens arrangement. The lamps which are utilized in the preferred embodimεnt may be high-intensity lamps which have light temperatures in the order of 3300 degrees K. to about 3400 degrees K. The temperature at the fiber optics face is on the order of 200 degrees F. In the absence of a fan and cooling duct using the teachings of the present invention, the temperature at light-receiving end 32 of light conduit 30 may be on the order of 600 degrees F. or higher.

A fan that can be used for the cooling fan in practicing thε prεsεnt invention is manufactured by Thor,grεn and is referrεd to as a "Lεxan Clear Fan Blade," which is made of a substantially transparent material that will not melt or deform in the apparatus described in this application.

The high-intensity light source described herein has a wide rangε of applications not disclosεd herein in detail. The high-intensity light source can be utilized for a projector, as light sources for a wide rangε of types of fiber optics, for pools, spas, or any other applications in which cool non¬ electric light is desirable. Also, the high-intensity light source can be used in theaters, stages, and the likε. In such applications, thε prεsent invention permits use of standard thεater light filter gels to control the color of the light.

In addition, the tεachings of the presεnt invention can bε 1 utilizεd in a number of applications, such as projector light,

2 decorative lamps, and other applications which require cool

3 light that will not heat surfaces it strikes.

4

5 Although thε prεferred embodiments of the invention have

6 been illustrated and described, it is apparent that these can be

7 modified by those skilled in the art and that the scope of the

8 invention is not intended to be restricted to any particular

9 form or arrangement, or to any specific embodiment disclosed 0 herein, or any specific use, since the present invention may be 1 modified in various particulars or relations without departing from the spirit or scope of the claimed invention shown and described herein, of which thε apparatus shown is intended only for illustration and for disclosure of an operative embodiment

.:. :ι and not to show all of the various forms or modifications which 0 jl might embody the invention.

Thε invεntion has been described in considerable detail in ordεr to comply with thε patent laws by providing a full public disclosure of one of its forms. Such detailεd description is not, however, intended to limit the broad features or principles of the invention, or the scope of the patent property to be granted.

Claims

HAT IS CLAIMED IS:

1. A light source for a light conduit illumination system comprising:

(a) a housing having sidewalls and a top and a bottom; (b) a source of light mounted within said housing;

(c) at least one light conduit having two ends, one said end being a light-receiving end, and the other said end being a light-transmitting end, said light- • receiving end being disposed within said housing on a line-of-sight with said light source; and

(d) means for cooling said light-receiving end of said light conduit, said cooling means being mounted in said housing and disposed between said light source and said light-receiving end of said light conduit.

2. The apparatus according to claim 1 wherein said light source further comprises a focusing reflector mounted in said housing and disposed on the line-of-sight connecting said light source and said light-receiving end, such that said light source is between said reflector and said light-receiving end of said light conduit.

-55- 3. The apparatus according to claim 2 wherein said light-receiving end of said light conduit is disposed at said focal point of said concave focusing reflector.

4. The apparatus according to any one of the preceding claims further comprising an envelope enclosing said light-receiving end of said light-conduit, and means for sealing said light-receiving end of said light conduit inside said envelope, thereby preventing deterioration due to oxidation of said light conduit.

5. The apparatus according to any one of the preceding claims wherein said housing further comprises*.

(a) a cooling duct having a cooling air inlet disposed adjacent said cooling means, and terminating in an exhaust port in a sidewall of said housing, said cooling means being disposed to move air into said cooling air inlet and through said cooling duct; and

(b) an air inlet in a sidewall of said housing, for admitting ambient air from outside said housing as said fan blows air out of said housing through said cooling duct. -56-

6. The apparatus according to claim 5 wherein said cooling duct further comprises an elbow disposed intermediate said cooling duct air inlet and said exhaust port, and said cooling duct tapers from said elbow to said exhaust port.

7. A light source for a light conduit illumination system, comprising:

(a) a housing having sidewalls and a top and a bottom; (b) a high-intensity lamp mounted within said housing;

(c) at least one light conduit having two ends, one said end being a light-receiving end, the other said end being a light-transmitting end, said light- receiving end being disposed within said housing on a line-of-sight with said lamp;

(d) a concave light focusing reflector disposed adjacent said light source along said line-of-sight such that said lamp is between said light-receiving end of said light conduit and said lamp, for focusing the light from said light source at a focal point remote from said light source, with said light-receiving end of said light conduit being disposed near said focal point; (e) a light-transmitting envelope enclosing said light-receiving end of said light conduit secured within said housing, and means for sealing said light- transmitting envelope, thereby preventing deterioration of said light conduit due to chemical reactions with air; and

(f) a fan disposed between said lamp and said light-receiving end of said light conduit, said fan positioned to blow directly on said light-receiving end of said light conduit, and means for driving said fan.

8. The apparatus according -to claim 7 further comprising a cooling duct within said housing, said cooling duct including a cooling duct air inlet disposed adjacent said fan so that said fan blows directly into said cooling duct air inlet, and said cooling duct terminating in an exhaust port in said sidewall of said housing.

9. The apparatus according to claim 7 or 8 further comprising an envelope for enclosing said light-receiving end of said light conduit, and means for sealing said light-receiving end of said light conduit inside said envelope, thereby preventing deterioration of said light-receiving end of said light conduit due to chemical reaction with ambient air.

10. The apparatus according to claim 9 further comprising:

(a) an envelope consisting of a glass tube having one permanently sealed end and one open end; (b) a tapered stopper having an axially disposed aperature therethrough;

(c) a threaded projection having an axially disposed aperature therethrough fixedly attached to one said sidewall of said housing and penetratiing said housing and said cooling duct at a location intermediate sa-id cooling duct air inlet and said elbow; and

(d) a threaded cap adopted to cooperate with ^• said threaded projection;

(e) whereby said threaded cap is positioned along the length of said light conduit, said light receiving-end of said light conduit is inserted through said aperature of said stopper and into said glass tube, said stopper is inserted into said glass tube, and said threaded cap is screwed onto said threaded projection, thereby squeezing said stopper against said light conduit and the internal^' sidewalls of said glass tube, sealing said tube.