Multiple wavelength light processor

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MULTIPLE WAVELENGTH. LGHT perimeter, an exit face to pass energy to the exterior of PROCESSOR the perimeter in a direction towards the reverse side of the body from the side of the incidence, and a Totally

This application is a continuation-in-part of prior U.S. Internally Reflecting face angled relative to the entry application Ser. No. 08/415,274 filed Apr. 7, 1995, now U.S. 5 and exit faces to redirect towards the exit face the Pat. No. 5,577,492 issued Nov. 26, 1996, which is a radiant energy incident from the entry face. continuation-in-part of Ser. No. 07/869,003 filed Apr. 16, A further object is to provide body means located for 1992, now U.S. Pat. No. 5,404,869. generally redirecting incident radiant energy towards a pre determined target zone situated apart from and on the

BACKGROUND OF THE INVENTION 10 reverse side of the body means relative to the side of the This invention relates generally to radiant, particularly incidence.

electromagnetic, energy concentration, redirection, and These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be manipulation, and improves over the subject matter of U.S. more fully understood from the following specification and Pat. No. 4337,759. It more particularly concerns apparatus and method for employing LED means in combination with 15 drawings, in which:

a transparent lens means with elements thereof using Total DRAWING DESCRIPTION

Internal Reflection (TIR); more specifically, it concerns employing mixing of light of different frequencies for illu of FIG. 1 is a vertical section in elevation showing one form apparatus embodying a TIR lens;

mination of a receiver, as for example a TIR lens.

Uses of TIR lenses are disclosed in the above references 20 FIG. 2 is a vertical section in elevation showing another application Ser. Nos. 08/415,274 and 07/869,003. Light form of apparatus embodying a TIR lens; emitting diodes (LEDs) that emit monochromatic light are FIG. 3 is an enlarged section on lines 3-3 of FIG. 2; also known. No way has been known to optically couple FIGS. 4a-4e are enlarged sections through elements of LEDs and light receivers, such as TIR lenses, to illuminate 25 various configurations;

such receivers with light of controllably selected color. FIG. 5 is a view like FIG. 1 showing a portion of a solar There is need for method and means to achieve such optical optical concentrator of somewhat different and employed coupling. configuration;

FIG. 6 is a schematic showing two devices, operating in

SUMMARY OF THE INVENTION

30 conjunction, one of which is like that of FIG. 1 or 5, and the

It is a major object of the present invention to provide other being a collimator;

method and apparatus to meet the above need. Basically, the FIG. 7 is an enlarged section through a collimator as used radiant energy redirecting system of the invention com in FIG. 6;

prises: FIGS. 8-11, 13, 14 and 15 are schematics showing a) at least two light-emitting sources, each emitting dif 35 different applications of the radiant energy concentrating ferent frequency light, means;

b) an optical cavity receiving light output from the FIGS. 12a and 12b are fragmentary sections showing sources, to mix therein, and act as a secondary emitter, modified concentrators;

FIGS.

c) a light receiver positioned to be illuminated by light 40 ments: 16-18 show various curved lens surface arrange from the secondary emitter.

As will be seen, the optical cavity is typically located ingFIGS. 19a–19e are sections producing light rays of vary angularity, as shown;

between the light-emitting sources and the light receiver, FIG. 20 is a section of a facet with three curved faces, and has light reflective wall means for reflecting and illustrating the general principles of facet design; re-reflecting light received from the light-emitting sources. 45

The latter may advantageously comprise LED dice. Also, the energy concentratingis a section showing a further modified radiant light reflective wall means of the cavity is typically diffu diode; means for use with a light-emitting sively reflective.

FIG.22 is a section showing yet another modified radiant

It is another object of the invention to employ three of the energy

LED dice, to generate red, green and blue light. Control 50 (IR) rays; concentrating means made of silicon to pass infrared means may be provided to control time-selective energiza FIG. 23 is a section showing a radiant energy transmitting tion of the dice, thereby to achieve controlled color illumi body means, as in FIG. 21a, directing converging light nation of the receiver, as for example a TIR lens. toward a light pipe;

Another object is to provide a combination that com FIG. 24 is a section showing a radiant energy transmitting prises: 55 means, directing diverging light as in a floodlight;

a) a TER lens, FIG.25 is a section showing a radiant energy transmitting b) a light source for the lens, and optically coupled means, directing light from a layer-stimulated sample to therewith, converge into a spectroscopic analyzer; c) the source comprising LED means. FIG. 26 is a section showing a radiant energy transmitting Yet another object is to provide a light receiver that means, directing light from a toroidal source; comprises: FIG. 27 is a section like FIG.25 but showing provision of i) a radiant energy transmitting body means, a second lens, and a filter, in the path of collimated light or ii) that means comprising multiple elements, each of radiation;

which acts as a radiant energy redirecting module, 65 FIG. 28 is a schematic view of a receiver, such as a TIR having on its cross-sectional perimeter an entry face to lens as referred to, in combination with LED dice and a light receive incidence of the energy into the interior of the mixer cavity coupled between the dice and the receiver; and

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FIG. 29 is a system block diagram. plate 32 supports reflector 30, as well as the dome-shaped DETALED DESCRIPTION lens 10 and 29, via extreme outer edge portion 10a of the body means 10. Aring gear 33 supports plate 32, and meshes

As described in U.S. Pat. No. 4337,759, and referring to with spur gear 34. Drive motor 35 rotates gear 34 to FIG. 1, radiant energy transmitting body means 10, in the controllably rotate ring gear 33, and control unit 36 controls shape of a cover or dome, has multiple facets or elements as motor 35. Unit 36 is responsive to photocells 37 and 38 in at 11, each facet having an entry face to receive impinge such manner that the photocells remain directed toward the ment of such radiation, an exit face to pass energy to the light source. The photocells are suitably carried at 99 by the exterior of the body, and an internal reflection face angled plate 32, as for example near its periphery. relative to the entry and exit faces to reflect radiant energy 10 Target 15 may for example comprise a fluid receptacle incident on the reflection face toward the exit face. For which is heat conductive, to transmit heat to fluid in the example, in FIGS. 1 and 4d, a selected facet 11 has, in receptacle, as for example water in a pipe. vertical cross section, an entry face 12 made up of In FIGS. 2 and 3, the numerals 100 and 129 designate stairstepped faces 12a and 12b, an exit face 13 facing the lenses corresponding to lenses 10 and 29 described above. zone of target 15, and an internal reflection face 14. Radiant 15 They are elongated in the direction of arrow 149 and are energy, such as light, is represented by rays 16a and 16b carried by supports indicated at 150 and 151. V-shaped entering the body means 10 at flat face 12a and normal shroud 152 has edgeportions 152a connected to the opposite thereto, and passing internally of the facet for reflection by edges of lens body 100, so that the shroud and lenses define face 14. For this purpose, the face may be silvered at 17. The an enclosure.

reflected rays 16c then pass toward and through exit face 13, 20 A second and insulative tubular shroud 153 extends normal thereto, and directly toward the target zone. within that enclosure, about a tank 154 which has fixed The body means 10 may consist of solid transparent (nonrotatable) position. A support for the tank may take the material, such as glass or plastic, for example. form of legs indicated at 155 and 156, bearings being The multiple facets 11 shown in FIG. 1 may extend 25 provided at 157 and 158 to allow tank and shroud rotation annularly about and define a common axis 18; or they may about central axis 159, along with the lens assembly. The extend in parallel relation (normal to the plane of FIG. 1) at shroud 153 is cut-away at locations 160 and 161 to allow opposite sides of a plane as alternatively represented by 18, entry of radiant energy from the lens assembly, to be and which is normal to the plane of FIG.1. In either event, absorbed by the tank, while heated air is prevented from corresponding points on the facets define a concave surface, escaping gap 162 by wipers 163; the enclosure has a as for example at (defined by the tips 22 of the facets closest 30 reflecting interior surface 152b. the target), and characterized in that radiant energy passing Cool liquid, such as water, enters the tank via pipe 164, is through the exit faces is directed generally toward the target heated therein, and discharges into the tank lower end at zone. Tips 22 are formed at the intersections of the faces 13 164a, Warmed liquid slowly flows at 200 back up the tank, and 14. Surface 21 is parabolic. 35 being further heated by contact with the exterior of pipe 164, The series of facets in FIG. 1 is further characterized by the liquid leaving the tank at outlet 165. A sacrificial anode the existence of tapered gaps 23 between adjacent faces 24 166 in the water 200 is adapted to corrode, electrolytically and 14 of the projecting portions of the facets. Faces 24 are suppressing any corrosion of the tank itself. Also, a back-up inactive surfaces, i.e., do not pass the radiation. See for heater 167 in water 200 is supplied with electrical current to example representative rays 25 and 26 in FIG. 1. Ray 25 is heat water in the tank as when solar radiation is blocked or redirected by its associated facet almost 90° toward the non-existent, as at night. An air-gap may be provided at 162 target, near the outer edge 27 of the TIR lens 10. Study of between shroud 153 and the tankitself. Sun tracking mecha FIGS. 1 and 4 will show that angle O (the bend angle of the nism is indicated at 170, to rotate the assembly to maintain ray) increases for facets increasing in distance from axis or the sun's rays incident normally toward the lenses 100 and plane 18; and that angle B (the angularity of face 14 relative 45 129, i.e., in direction 171 in FIG. 3. to a line or plane parallel to line or plane 18) increases for In operation, all radiation directed parallel to arrow 171 facets increasing in distance from 18. Also, the entry faces and striking the lenses 100 and 129, is redirected toward the 12 form stairstep patterns. tank, as facilitated by gaps 160 and 161, to heat the liquidin FIG. 1 further shows a Fresnel lens 29 associated with the tank. Also note windows 162 and 163. Wide angle, i.e., TIR lens or body 10, and located at a mid-portion of the 50 almost 180°, collection of the solar rays is employed, as latter; thus Fresnel lens 29, which refracts incident radiant described above in FIG.1. The gap walls 153a are reflective, energy toward target 15, is located in the path of rays 30, and may have other, curved shapes besides the straightlines which are redirected the least, i.e., at the smallest angles, shown here, for the purpose of secondary concentration. toward the target. Lens 29 may be integral with lens 10, for Stray radiation from the diffuse sources, such as skylight, is example. 55 absorbed by blackening the surface 153a of shroud 153 and Further, areflector or mirror surface is shown at 30 spaced of lens support fin at 130.

from and facing the facets at the target side thereof. Surface Various geometric configurations of elements and arrays 30 is arranged to reflect stray or divergentradiation from the of elements are possible, wherein various element configu extreme outward facets toward the target. See ray 31 in this rations have the same relative angles of the three active regard, and reflection point 31a. This allows target 15 to faces, but differing deployments within the transparent halve the area exposed to heat loss that it would have means; e.g., the TR face can be in faceted slots on either without surface 30, since the bottom non-illuminated half side of the body means or on the walls of tunnels within the could be well insulated. latter, while the entry faces can be on faceted steps or even Also shown in FIG. 1 is one form of means to controllably on a completely smooth cover surface.

tilt the assembly of lenses 10 and 29 and reflector 30 to cause 65 In FIG. 4a, tunnel 40 forms TIR face 41, while exit face axis 18 to remain directed toward a relatively moving source 42 has stairsteps 42a and 42b. In FIG. 4b, slot 50 is on the of radiation, as for example the sun. In that example, a base entry side of the body means, having TIR face 51 and entry

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face 54. Exit face 52 has stairsteps 52a and 52b. In FIG. 4c, Another method of widening the slots is the faceted exit tunnel 60 forms TIR face 61, and entry face 62 and exit face face, shown in FIG. 4e. Here slot 70 has been opened until 64 are on Smooth continuous surfaces. However, TIR face it nearly impinges upon extreme ray 73b. Exit face 74 has 61 must be longer than TIR faces 41 of FIG.4a or 51 of FIG. miniature stairsteps 74a and 74b, respectively normal to and 4b, because of the refractive bending of ray 63 by entry face parallel to reflected ray 73b. Alternatively, a thin, micro 62. In general, the length of a TIRface relative to facet width structured series of elements of high refractive index (say

n=4) can be embedded in the body means to form more

TIRLENGTH=cos 8/(cosm cosm) favorably shaped elements. The particular manufacturing where m is the incident angle of ray 63a with surface method and design application will determine the place of normal 66, 8 is the angle of the refracted ray 63b with O transition to a Fresnellens, or alternatively to a window, that 66, K the incident angle of reflected ray 63c with exit passes rays to a small parabolic reflector below the target, surface normal 67, and the angle of refracted by 63d which is thereby illuminated from a full circle of directions. with 67. The relationships of these angles are given by Another possible configuration would have the outer parts Snell's law: of the redirecting means sending radiant energy to a central sin m=n sin 8, and sin -n sink 15 target while the inner parts redirected energy to outer targets where n is the index of refraction of the body means using only large bend angles throughout. All these configu material. For contiguous elements to redirect to a target all rations are derivatives of the basic method of this invention: the parallel rays incident upon them, neighboring elements upon multiple TIR-transmitting elements, properly placed must be relatively positioned everywhere on or above a entry, exit, and TIR faces redirect radiant energy to a parabola with the target as its focus and a rim slope equal to 20 predetermined target Zone, or into a predetermined target half the rim angle (i.e., the redirective bend angle of the solid angle.

outermost elements). Also usable is a cover means (as at 10 or 110) whose focal In FIG. 4d, “extreme" ray 16c must clear tip 22 of the length can be shorter than any parabolic mirror with con inward adjacentfacet, while the other extreme ray, 16b, must centrations twice as high, but which is free from shading and clear top 27 of slot 23. These clearance conditions require 25 presents a convex surface with lower aerodynamic drag than that the lens slope anglem be greater than or equal to the TIR the concave parabolic mirror. Its target is near the center of tilt angle, which is geometrically equivalent to tangent line gravity and closer to the ground than that of the parabolic 22 being on or above the parabola. reflector making fixed receiver means easier to design and Note that all of the configurations of FIG. 4 have the same maintain. Finally, the nearly 100% reflective efficiency of bendangle O, and except for FIG. 4c, the same normal entry 30 the TIR faces give much greater potential for high efficien and exit faces. See for example the elements 311 of the cies than does the parabolic mirror.

“cover 310 in FIG. 5, above the parabola 321 tangent to the In FIGS. 1 and 5, it will be understood that the elements tips 322. See also line 324. Those tips below the parabola, 11 and 311 join together, integrally and continuously, to such as for a quarter-circle 325 with the same slope at the form a radiant energy transmitting means in the general form rim, would in this stairstep configuration suffer some inter 35 of a cover. The latter has an energy entry surface (top surface element impingement, about 10% for both cylinders and in FIG. 1, for example) and an exit surface (bottom surface spheres; but the use of a thin, flexible, inflatable dome for a in FIG. 1) lying on opposite sides of the cover. The cover transparent cover means might be worth such a loss, espe causes radiant energy leaving the exit surface to have a cially since the untargeted rays would still be redirected to generally different direction than the direction of energy a locus within the cover means, to assist the pressurization incidence on the entry surface. Also, multiple TIR faces are by heating the enclosed air. See FIG. 11 for a non-impinging situated on the exit surface adjacent slots proximate the exit circular configuration. surface, as referred to above. The entry surface has a faceted An alternative facet style seeks to minimize such stairstep configuration. The exit surface of the cover lies impingement losses by concentrating the rays before they beyond and further from the target than a parabola (see 21 strike the TIR face, which can thereby be smaller to reduce 45 and 321). The cover may be constructed of transparent said impingement. Convex and concave entry and exit faces material, as for example plastic.

will do this, though with some decrement of the cover's FIG. 8 schematically shows a means 410 corresponding to concentration ratio or acceptance angle, which for some the means 10 of FIG. 1 or 310 of FIG. 5, or equivalent. A applications is far outweighed by bringing the transparent target zone is shown at 415. A retroreflector means 412 is redirecting means even closer to the target. 50 spaced behind and facing the target zone so as to redirect For the smaller bendangles, difficulties are encountered in radiant energy upon the target zone. See ray 413. the narrowness required of the tunnels or slots 23 in FIG. 4d FIG. 9 schematically shows a radiant energy source forming the TIR faces of the low bend-angle elements. This means (as for example a light source) at 430 at the target can be somewhat alleviated by raising the profile of the zone. Radiant energy emitted by the source means 430 is transparent means 310 above the parabola 321 to widen the 55 redirected by the body means 435 (like 10 or 310) in reverse slots and tunnels beyond their minimum widths. Another relation. See ray 436.

form of such an alleviation is a backbending exit face, 311 FIGS. 10a and 10b show two variations of a "uni-bend" of FIG. 5, so angled that its refractive redirection opposes lens with uniform facets extending annularly about a cylin the redirection of the TIR face, which can thereby have a drical target. In. FIG. 10a, all the facets 444 of conical body greater redirective bend angle with a less steep slope, giving means 440 bendrays 443 through 90° onto cylindrical target wider tunnels or slots. 441. In FIG. 10b, flat body means 445 has identical facets In FIG. 5, note that ray 330 strikes the exit face 11 448 bending rays 447 through 45° upon cylindrical target non-normally, so that ray 330a is bent back toward the 446.

target. This enables a wider slot 323 than if the exit face was FIG. 11 shows a structural means 460 enclosing the space normal and the TER face was at a steeper angle. The 65 461 behind the exit face of the cover means 459 (like 10 or above-mentioned convex entry face will also widen the slots 310), so that pressurization of the atmosphere of space 461 or tunnels. will hold the flexible cover means in its distended or circular

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shape, with center of curvature at point 426. See target Zone When a source of radiant energy is placed in Zone 562, the 462, pressurization means such as a pump 463 and ray 464. visible wavelength rays will follow the reverse path of rays A thin film 465 adheres to the inside of cover means 459, 563, i.e., be collimated, while the invisible longer wave having miniature sawtoothfacets 467 as shown in the insert. length heat rays will be diverged more outward from the FIG. 12a shows a plurality (two for example) of target visible beam, so that spotlights on actors will not subject zones 470 and 471 to receive radiant energy from the visible them to a heat load several times greater than that of the transmitting body means 472 (like 10 or 310). Each element radiation.

Certain aspects of FIGS. 1-15 were also discussed in prior 473 redirects energy in a plurality of directions, toward the patent target zones. Thus, each element 473 may be like element 10 4,337,759.

or 310 described above but have a TIR face divided into two 10 FIG. 16 may be considered to correspond generally to sub-faces 474 and 475 at slightly different angles to accom FIG. 4a or FIG. 4b, i.e., to present a lens body 600 having an entry face 601, a TIR face 602, and an exit face 603 on plish the reflection of the two rays 476 and 477, respectively the body 600. Such faces 601 and 603 may be faceted, as in directed by the faces 474 and 475 toward the two target the styles shown in FIGS. 1, 3, 7, 8, 9, 10, and 13. Rather

ZOICS.

In FIG. 12b, TIR face 453 is the exit face for ray 451; 15 than all such faces being flat, face 601 is convexly curved, while TTR face 454 is the exit face for ray 452. This 603 arefrom away the body 600, as shown; whereas faces 602 and flat, as previously described. Diverging entry rays symmetrical case of twin 60° bends may be varied to give 605 are refracted at 605a for reflection at 605b, and travel at two different right and left hand bends, with differing 605c toward face 603. The rays pass through exit face 603 division of the incoming radiant energy. and are in general refracted to travel externally at 605d, as In FIG. 13, the cover means 480 (like 10 or 310) has 20 shown. If exitface 603 was convexly curved, then rays 605d different groups of elements redirecting radiant energy could be converging. The curvature of entry face 601 toward different target zones. Thus, the elements at locus eliminates the divergence and keeps any rays from missing 481 direct radiant energy toward target 482; and the ele TIR face 602.

ments at locus 483 direct energy toward target 484. See rays In FIG. 17, entry face 611 is flat, as is exit face 613; 485 and 486. 25 however, TTR face 612 is concave toward the incident ray In FIG. 6, cover or body means 510 corresponds to 10 or side of that face, as shown. Diverging entry rays 615 pass 310 described above. A secondary radiant energy redirecting through face 611 and travel at 615a, within body 610, for means is provided at 520 to intercept the radiant energy from reflection at 615b, at different points and angles, for travel at body 510 and to redirectit. See rays 521 with segments 521a 615c toward face 613. The rays pass through that face, and falling on body 510; redirected segments 521b falling on 30 are in general refracted, and travel externally at 615d, as body 520; and secondarily redirected segments 521c trans shown. The curvature of the TIR face 612 has made rays mitted by body 520. 615d parallel, while restricting the amount of exit face 613 FIG.7 shows body 520 in detail, with entry faces 530, exit that is used, enabling the entire lens to have a higher profile. faces 531, and TIR faces 532. The rays 521c are parallel, in In FIG. 18, entry face 621 is flat, as is TIR face 622; this instance, i.e., collimated, so that means 520 may be 35 however, exit face 623 is concave away from the body 620, regarded as a collimator. i.e., away from TER face 622, as shown. Entry rays 625, The means 550 shown in FIG. 14 is like 10 and 300, which may be parallel, pass through face 621 and travel at except that the exit faces 551 are individually angled relative 625a, within body 620, for reflection at 625b at different to radiant energy passing through them, so as to cause points and angles, for travel at 625c toward face 623. The reflective redirection of the radiant energy. See beam 552 40 rays then pass through that face and are in general refracted refracted at face 551. Also in FIG. 14, the exitfaces 551 may to travel externally at 625d, as shown. Exit face 623 is fully be considered to refractively redirect radiant energy in flashed, as would be desirable for a converging TIR lens. partial opposition to the redirection by the TIR faces 553, the Other possibilities are as follows: latter extending at less steep angles (than in FIGS. 1 and 5) so as to widen the slots 554. Note also in FIG. 14 that the 45 entry face is smooth and unfaceted, at 556, and that exit face flat COWex concave 551 is parallel to refracted ray 552b, giving the maximum A X backbend and the lowest possible slope of entry surface 556, which in fact is lower than the parabola 321 or the quarter entry face circle 325 in FIG.S. 50 exit face x TIR face

In FIG. 15, the body means 560 is like that at 10 or 310, B except that it utilizes the variation index of refraction that varies with the wavelength of the radiant energy, so as to entry face x constitute a wavelength separating, radiating energy exit face x

redirecting, transmitting body means. Two target zones 561 55

and 562 are shown, and are spaced apart to receive different wavelengths of the wavelength separated, redirected, radiant entry face k energy. See incident ray 563 which separates into ray 563a exit face X of one wavelength directed toward target 561, and ray 563b TIR face X of another wavelength directed toward target 562.

Also in FIG. 15, either target may be considered as a In FIGS. 19a, 19b and 19c, the bodies 650, 660 and 670 means to convert radiant energy to electricity. One such are closely similar to body 740 shown and described in FIG. means is a photovoltaic cell. Such a device may be located 21. The angularities of the annular facets are slightly varied, at the target zones in FIGS. 1 and 5. In FIG. 15, one target so that the body 660 produces collimated light rays 664; may comprise a photoillumination means receiving visible 65 body 650 produces converging light rays at 654; and a body wavelengths; and the other target may comprise a thermal 670 produces diverging light rays 674. The light source in receiver receiving invisible wavelengths at Zone 561. each case is shown at 680. In each case, the top surface 659,

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669, and 679 of the lens is circularly curved in the section (3) exit-face curvature minimizes the size of the focal spot shown, or spherically curved for an annular lens. of converging TIR lenses, and minimizes the beam diver In FIG. 20, lens body 700 acts as a converging TIR lens, gence of collimating TIR lenses.

in the same manner as lens 650 in FIG. 19a. Its performance Non-circular profiles of these curved faces may be is superior because of its full flashing, which gives more selected in order to provide uniform illumination by the effective focusing, and higher profile, and which leads to facet.

Smaller angular magnification of the light source, and a In addition, all the facets of the lens could be designed to Smaller focal spot. Upper light ray 701 and lower light ray have the same size focal spot, which would then be uni 702 are the definingrays for the calculation of the angles of formly illuminated. This discussion of FIG. 20 may be the boundaries of facet 703 and of the position of inwardly O considered an important aspect of the invention, improving adjacent facet 704. The slope of lens profile line 705 is to be over or not suggested by, subject matter of U.S. Pat. No. maximized. The defining rays are generally diverging but 4,337,759.

can come from different parts of the light source; for In FIG. 21, the axis of the annular, radiant energy trans example, upper ray 701 comes from the bottom of the light mitting body 740 appears at 751. The body has multiple source, while lower ray 702 comes from the top of the light 15 annular facets 742 to 746 which are generally concentrically source, so that they constitute the extreme rays of all light arranged but having tips 742d to 746d progressively closer emitted by the source. to plane 750 normal to axis 751. Face 742a of facet 742 is If the facet-defining upper and lower rays are not the convex toward face 742b; and face 742b is concave toward extreme rays of the light source, then some fraction of its face 742a in the section shown. This relationship obtains for output light will be redirected by the lens into the output other facets, as shown.

rays. Such a case may occur if there is a tradeoff between 20 A light-emitting diode (LED) 758 is located at the inter this fraction and the tightness of the focusing, to be resolved section of plane 750 with axis 751 and emits light rays by the particular application of the lens. toward the body 740. Ray 753 passes through face 742a, is Facet 703 is defined by notch 703n (shown here as a refracted toward TIR face 742b and is reflected toward and fillet), tip 703t, upper point 703u of entry face 706, and on passes through upper flat face 748. See also ray 752 passing exit face 707, outer point 706o and inner point 706i. 25

Inwardly adjacent facet 704 provides three limiting points through face 743a, reflecting at TIR face 743b, and passing that act analogously to pupils of conventional optical sys upwardlyupper through face 748a, angled as shown. All rays passing tems: tip 704t defines upper ray 701, while both notch 704n transverse width offaces beyond the 748 and 748a are collimated. The body 740 may be from 0.12 to one and outer exit face 704o must be cleared by lower ray 702. inch, for example, and the transparent body 740 may consist The convex curvature of entry face 706 accommodates the 30 of molded plastic material. A refractive section without divergence of the defining rays by assuring that upper ray 701 does not miss TIR face 708 and that lower ray 702 does facets appears at 719. Smaller ratios of lens diameter to LED miss notch 704n. size may have outermost facets large, and successively For the sake of diagrammatic clarity, exit face 707 is inward facets smaller, in order to have a higher lens profile relatively close to TIR face 708. A thicker lens with a more 35 and better collimation curved facets are necessary for. distant exit face would employ convex curvature (as on the In FIG. 22, the radiant energy transmitting body 760 may TIR face 708c) to assure that the defining rays do not miss have the same general construction as shown in FIGS. 20 the edges of exit face 707. If they did miss, they would not and 21. The lens body 760 consists of silicon, or a similar be lost, since they would totally internally reflect on riser material, for passing infrared rays, but blocking visible light faces 709 or 710, and enter the lens output with only modest rays, while transmitting infrared rays. An arc lamp radiant angular errors. Riser face 709 is angled to just clear lower 40 energy source is shown at 764, at the same position as the ray 702, after it has left the lens. Optically inactive face 711 LED in FIG. 20.

is kept at a minimum draft angle determined by the manu A reflector surface 765 may be employed to extend in facturing method (for injection molds, it is typically 2 off plane 766 corresponding to plane 750 in FIG. 21 with a the mold-pulling direction). Face 711 assists maximizing of parabolic section 762. The infrared rays emanating at 767 lens profile by enabling entry face 706 to be angled more 45 are typically collimated but may be divergent or convergent, downward than is the case with lens 650 of FIG. 19a, where as in FIGS. 19a and 19c. Note that unfaceted central section there is a straight line between a facet tip and the notch of 770 refracts rays, as shown. The arc light source at 764 may the inwardly adjacent facet. be produced by anode and cathode elements 764a and 764b. In Summary, a unique determination of the four angulari Top exit surface 759 is circularly curved in the section ties of the facet (three for its faces and one for the lens 50 shown; but the lens may have external, stairstep faceting. profile) requires four conditions: (1) overall bend angle; (2) Protective transparent envelope 769 keeps outside air away upper ray falling on the TIR face; (3) lower ray clearing from the arc.

notch of the inwardly adjacent face; and (4) lower ray In FIG. 23, the body means 780 may have the same or clearing the outer edge of exit facet of the inwardly adjacent similar construction as that of FIG. 19a, for producing and facet. The curvatures of the three optically active faces of the 55 directing convergent light at 781 into the entrance end 782 facet are individually determined: of a lightpipe 783. The lens has an upwardly convex arcuate (1) entry-face curvature helps to maximize the slope of upper exit surface or face 785, an entrance face or faces 786, the lens profile line, by allowing the tip of the inwardly and a TER face or faces 787. Faces 786 and 787 taper adjacent facet to rise while keeping the higher upper ray downwardly toward plane 790, corresponding to plane 710 from missing the TIR face (this reduces the divergence of in FIG. 21. A central light source 788 is positioned in the the output light of the inner facets of the lens by increasing manner of the LED in FIG. 21. A planar back mirror 789 their height above the source); extends in plane 790 corresponding to plane 710 and faces (2) TIR-face curvature also helps to maximize lens slope upwardly. This device may input up to 80% of the light into by allow the notch of the inwardly adjacent facet to rise; in pipe 783, rather than 10% of the light as via a conventional addition, TR-face curvature enables the exitface to be fully 65 ellipsoidal reflector.

flashed, an important characteristic for several illumination In FIG. 24, the body means 800 may have the same or applications; similar construction as that of FIG. 21c. Circularly curved

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top surface 801 is curved downwardly. The lens axis, in the Also shown, as in FIG. 27, is a microscope objective lens case of an annular set of facets, is indicated at 802. Facets 954 which can slide axially in a bore in lens 950, and focus are seen from 803 to 812. A typical annular facet 809 has an auxiliary source light 965 onto the target or laser 951. Note entrance face 809a and a TIR face 809b. Note ray 820 path the cylindrical periphery 970 of 954 parallel to axis 986, and passing throughface 809a and face 801, and totally reflected sliding in bore 967 of lens 950. Ameans to adjustably move at face 809b. In the section shown, each of the faces 809a objective lens 954 axially is schematically shown at 968. and 809b is flat. All entry faces have draft in the direction Auxiliary source light 965 may be redirected by mirror 953, 822, for ease of molding. The lens is transparent and may as shown, toward lens 954, for focusing onto the target 951. consist of molded plastic material. Referring now to FIG. 29, the apparatus 900 shown is a Alight source 825 is located on axis 802, and just above 10 multiple wavelength illuminator. It includes at least two the plane 826, is within the confines of the hollow lens, as light-emitting sources, each emitting different frequency in the above examples; and the rays 827 emanating from light. Such sources are indicated at 901. Three sources 901a, face 802 diverge, as in a floodlight application. The circular 901b, and 901c are shown, for emitting red, green and blue section half-angle subtended by the surface 801 is typically light; and they may advantageously comprise LED (light less than 45° and greater than 25° and is typically about 35°. 15 emitting diode) dice, clustered, as shown. In FIG.25, lens body 850 is the same as that of FIG. 21a, A light receiver is generally indicated at 902, and may except that the central refractive means has been replaced by comprise a TIR lens of the type described above. The microscope objective 854, which can slide axially inside the receiver is positioned to receive light originating at the lenstofocus on sample 851. Characteristic diffuse (i.e., in all sources 901, for illumination of the receiver. The light directions) emission 856 from sample 851 is collected by 20 transmitted by the receiver may be collimated, as indicated lens 850 and focused on analyzer entrance slit 832. Colli by rays 903. Viewing of rays is indicated at 904. mated laser beam 855 is reflected by mirror 853 into Located between, i.e., in the optical path of rays from 901 objective 854 and focused on sample 851. Mirror 853 is and the receiver is an optical cavity 905. The cavity receives removable in order to use microscope objective 854 to view light rays 906 from the sources 901, and effects mixing of sample 851 and exactly adjust its position. Lens body 850 25 such rays, in order to act as a secondary light emitter. Mixed could extend downward below sample 851 to collect even light output from 905 is transmitted at 907 to illuminate the more of the diffuse emission. Sample 851 may be a glass receiver. The cavity 905 typically has light reflective wall capillary containing a gas or liquid, a gold hemisphere means, indicated at 905a, and which is diffusively reflective. coated with a sample substance, an integrated circuit on a The cavity may be generally tubular to have an entrance end production line (checking material composition or 30 905b for rays 906, and an exit end 905c, for transmitting contamination), or a biological tissue sample. light 907, that comprises a mixture of rays 906. Wall means In FIG. 26, lens body 860 has a cross-section with axis 905a effects reflection and re-reflection of received rays 906 863, in order to accommodate toroidal (typically within the optical cavity, and toward the exit end 905c. Wall fluorescent) light source 861. Beneath this lamp is annular means 905a may be annular about axis 908. involute reflector 862, with disc-shaped, planar mirror sec 35 The secondary emitter acts as a uniform source for a lens tion 864 inside it and annulus mirror 865 outside it. Annular or reflector, which is the output means of the radiation of the lens 866 refracts ray 868, which was reflected from involute far-field. It is a further object of this invention that the 862. Ray 869 is exactly analogous to ray 820 in FIG.24. Ray secondary emitter 905 have a shape, so as to give the output 867 is redirected by facet 870. The overall device of lamp, lens or reflector element 902 a nearly uniform output light lens, and reflector comprise a compact floodlamp that offers flux pattern over the output plane, and thus to compensate much narrower divergence and much higher efficiency than for the 1/R radiation falloff that is normally observed. possible with the prior art of reflector design. The walls of the optical cavity will normally be con Referring now to FIG. 27, the lens body 950 is the same structed of highly reflective material, with reflectivities as shown in FIG. 19b or as in FIG. 25, modified to collimate typically greater than 95%. Further, the walls will usually be light or a laser beam, supplied as indicated at 955. A light fabricated from highly diffusely reflective material, as source or light-emitting target (laser for example) 951 trans opposed to specularly reflecting material. It is possible to mits light to faceted side of the TIR lens body 950, the latter construct the walls from specularly reflecting materials redirecting the light rays, as shown by the broken lines 956 (such as reflective aluminum) provided that the walls of this and 980, to pass through first refracting lens means at material have a number of scattering centers or bumps built surface 950a and emerge as collimated light at 955. Such 50 into such walls, so as to randomize the directions of the light then impinges on and passes through the wavelength reflected radiation, and thus essentially reproducing the selective filter 982 and then through a second lens means effect of the diffusely reflecting surface. 983 indicated in the example as a focusing Fresnel lens. The The optimal shape of the secondary emitter 905 may be latter redirects or focuses light at 984 onto the sample, or an accomplished using geometry, as in surface area presented to analyser, 952. 55 the output optical device 902 per unit solid angle, or it may A wavelength-selective filter 982 is used to remove pas be accomplished by using non-uniform holographic diffus sively scattered light of the collimated laser beam.955, while ers or specially designed refractive element(s) at the surface allowing passage offluorescence wavelengths, such as those of the secondary emitter, or in close proximity to the generated in Raman spectroscopy, for stimulated emissions secondary emitter.

at 952. The filter 982 extends in a plane normal to principal An application for such a device is the uniform pixel axis 986 defined by the lens 950 and by lens 983, the filter illumination for indoor and outdoor LED displays. Another requiring normal incidence of light for good wavelength application would be for a low power, optically efficient selection, since the filter wavelength depends upon the angle LED backlight for liquid crystal displays (LCDS); and, in of incidence. The filter typically removes the laser wave particular, for head mounted displays. The tri-color LED lengths. The auxiliary or second lens means 983 can also act 65 illuminator 901 may have the red, green and blue dice driven to reduce any aberrations introduced by the annular TIR lens all at once and with appropriate drive currents to each dice, 950. such that white light is produced at 906 or any other color

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of the spectrum, by simple adjustments to the drive currents 15. A radiant energy redirecting system, comprising in of the individual LED dice. It is also possible to drive each combination:

LED in sequence (e.g., red, then green, then blue), such that a) at least two light-emitting sources, each emitting dif the unit 905 becomes a sequential backlight for a mono ferent frequency light, chrome LCD, and thus allows for an increase by a factor of b) an optical cavity receiving light output from the three the image resolution of the LCD display when com sources, to mix therein, and act as a secondary emitter, pared to full color active matrix displays of the same pixel c) a light receiver positioned to be illuminated by light size. Such an LCD display is indicated at 911, in the path of from said secondary emitter,

Referring now to FIG. 28, the elements thereof that d) there being thee of said sources providing red, green correspond to those of FIG. 29 bear the same identifying O and blue light, numerals. A planar mirror 915 is located just rearwardly of e) and including control means operatively connected the secondary emitter 905, for reflecting light forwardly with said sources to drive them in accordance with one toward the receiver 902 shown in the form of a collimating of the following:

TIR lens. A light ray integrating (mixing) cavity is shown at 15 i) all three dice are driven simultaneously to produce 90S. white light emitted from the secondary emitter, We claim: ii) the three dice are relatively driven to produce a 1. A radiant energy redirecting system, comprising in selected color light emitted from the secondary combination: emitter, a) at least two light-emitting sources, each emitting dif iii) the three dice are driven in sequence to produce red,

green and blue light emitted on different time incre b) an optical cavity receiving light output from the ments by the secondary emitter. sources, to mix therein, and act as a secondary emitter, 16. A radiant energy redirecting system, comprising in c) a light receiver positioned to be illuminated by light combination:

from said secondary emitter, a) at least two light-emitting sources, each emitting dif d) said cavity having light reflective wall means. 25 ferent frequency light, 2. The combination of claim 1 wherein said receiver is a b) an optical cavity receiving light output from the TR lens. sources, to mix therein, and act as a secondary emitter, 3. The combination of claim 1 wherein said wall means is c) a light receiver positioned to be illuminated by light diffusively reflective. from said secondary emitter, 4. The combination of claim 1 wherein said optical cavity 30 is located between said sources and said light receiver. d) and wherein said receiver comprises: 5. The combination of claim 1 wherein there are three of i) a radiant energy transmitting body means, said sources. ii) said means comprising multiple elements, each of 6. The combination of claim.5 wherein said three sources which acts as a radiant energy redirecting module, provide red, green and blue light. 35 having on its cross-sectional perimeter an entry face 7. The combination of claim 6 wherein said sources are to receive incidence of said energy into the interior clustered. of said perimeter, an exit face to pass said energy to 8. A radiant energy redirecting system, comprising in the exterior of said perimeter in a direction towards combination: the reverse side of the body from the side of said a) at least two light-emitting sources, each emitting dif incidence, and a Totally Internally Reflecting face ferent frequency light, angled relative to said entry and exit faces to redirect b) an optical cavity receiving light output from the towards said exit face the radiant energy incident from said entry face.

sources, to mix therein, and act as a secondary emitter, 17. The combination of claim 16 wherein c) a light receiver positioned to be illuminated by light 45 iii) said body means is located for generally redirecting from said secondary emitter, incident radiant energy towards a predetermined target d) said sources being LED dice. zone situated apart from and on the reverse side of said 9. The combination of claim 6 wherein said sources are body relative to the side of said incidence. LED dice. 18. The combination of claim 17 including 10. The combination of claim 1 including control means 50 iv) first lens means associated with at least one of said for controlling electrical energization of said sources. faces for redirecting radiant energy passing between 11. The combination of claim 9 including control means said entry and exit faces via said Totally Internally for controlling electrical energization of said LED dice. Reflecting face, said redirected radiant energy being 12. A radiant energy redirecting system, comprising in collimated, combination: 55 V) and second lens means spaced from said exit face to a) at least two light-emitting sources, each emitting dif receive said collimated radiant energy and to redirect ferent frequency light, same toward said target Zone.

b) an optical cavity receiving light output from the 19. The system of claim 18 wherein said first lens means sources, to mix therein, and act as a secondary emitter, is defined at least in part by said Totally Internally Reflecting c) a light receiver positioned to be illuminated by light 60 face.

from said secondary emitter, 20. The system of claim 18 wherein said second lens d) and wherein said receiver includes a TIR lens. means is a focusing Fresnel lens.

13. The combination of claim 9 wherein said receiver is 21. The system of claim 20 including a wavelength a TIR lens. selection filter in the path of said radiant energy collimated 14. The combination of claim 12 wherein said receiver is 65 and redirected toward said target Zone. a mirror associated with said cavity to reflect light originat 22. The system of claim 16 wherein the Totally Internally ing at said secondary emitter toward said TIR lens. Reflecting face is a body boundary, so that the index of

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refraction “n” of the substance of said transparent body 26. The system of claim 17 including a retroreflecting means at said boundary gives total internal reflection of all means spaced behind and facing said target Zone so as to radiant energy whose incident angle with the normal of said redirect radiant energy upon said target Zone. boundary at the point of incidence exceeds Brewster's angle, 27. The system of claim 16 including a radiant energy which equals the inverse sine of the reciprocal of “n”. redirecting means located to redirect light originating at said 23. The system of claim 16 wherein said perimeters of secondary emitter toward said TIR lens. said elements project from said cross section to extend 28. In combination:

linearly, in parallel relation, said entry faces facing said a) a TIR lens, incident radiant energy, said exit faces facing said target b) a light source means for said lens, and optically ZOC. 10 coupled therewith, 24. The system of claim 16 wherein said perimeters of c) said source means comprising LED means, said elements project from said cross section to extend d) and optical cavity means receiving light output from annularly about, and define a common axis, said entry faces said source means to reflect light for mixing in said facing said incident radiant energy, said exit faces facing cavity means for illuminating said TIR lens. said target Zone. 15 29. The combination of claim28 wherein said LED means 25. The system of claim 16 including a Fresnel lens includes multiple LED dice that emit light at different associated with said body means and located in a mid frequencies, when energized.

portion of said body means so as to redirect radiant energy through relatively small angles toward the target zone.