TW200807137A - Fluorescent volume light source - Google Patents

Abstract

An embodiment of the invention is an illumination system including a source of incoherent light capable of generating light in a first wavelength range and an elongate body that emits light in a second wavelength range when illuminated by light in the first wavelength range. The body has a length dimension, a width dimension and a height dimension. At least a portion of the body is tapered so as to increase in width and/or height along the length dimension. The body further includes an extraction surface. A first non-extraction surface extends along at least a portion of the length of the body and is disposed so as to share a common edge with the extraction surface. At least some of the light at the second wavelength is totally internally reflected at the non-extraction surface. At least one external reflector is disposed proximate to the non-extraction surface so as to create a gap between the external reflector and the non-extraction surface.

Description

200807137 IX. DESCRIPTION OF THE INVENTION: FIELD OF THE INVENTION The present invention relates to light sources, and in particular to the present invention relates to light sources that can be used in lighting systems (e.g., projection systems). [Prior Art] The brightness of an illumination source based on a type of light source is usually limited by the brightness of the light source itself. For example, an illumination source using a light-emitting diode (LED) typically has a brightness measured at a power per unit area of solid angle per unit area, since optical elements collecting light from the LED will retain at most the LED source. The optical expansion (Mendue), so the brightness is equal to or less than the brightness of the LED. Therefore, the brightness of the illumination source is limited. In some applications of illumination sources, such as projector illumination, LED illumination is not a competitive option because the brightness of currently available LEDs is too low. This is especially a problem for producing green illumination light because the visible spectral region of the semiconductor material used in the LED is less efficient in generating light. Other types of light sources may be able to produce a sufficiently bright beam, but they also have other disadvantages. For example, high pressure mercury lamps typically provide sufficient light for a projection system, but this type of lamp is relatively inefficient, requires a high voltage power supply, contains toxic mercury, and has a limited useful life. Solid-state sources such as LEDs are more efficient, operate at lower voltages, do not contain water lift, and are therefore safer, and have a longer life than lamps, typically lasting tens of thousands of hours. Therefore, there is a need for a solid state 121109.doc 200807137 light source that can be used in a lighting system and that is brighter than the current light source. [Summary of the Invention]

An embodiment of the present invention is an illumination system including an incoherent light source capable of generating light in a first wavelength range and a second wavelength range when illuminated by light in the first wavelength range The narrow body of light. The body has a length dimension, a width dimension and a height dimension. At least a portion of the body is tapered to increase width and/or twist along the length dimension. The body further includes an extraction surface. A first non-extracting surface extends along at least a portion of the length of the body and is positioned to share a common edge with the extraction surface. At least some of the second wavelength light is totally internally reflected at the non-extracted surface. At least one external reflector is disposed proximate the non-extracting surface to create a gap between the outer reflector and the non-extracting surface. [Embodiment] The present invention is applicable to a light source, and more particularly, the present invention is applicable to a light source used in an illumination system requiring a high brightness level. The brightness of a light source is measured by dividing the optical power (watts) by the amount of optical expansion. The amount of optical expansion is the area of the beam at the source multiplied by the flat of the refractive index = multiplied by the product of the solid angle of the beam. The optical spread of light is constant, i.e., if the solid angle of the beam is reduced without loss of light, the area of the beam is increased, for example, by increasing the area of illumination of the source. Since the amount of light expansion is constant, (b) the brightness of the light produced by the light source can only be increased by increasing the amount of light extracted from the light source. If the light source operates at its maximum output: then the brightness of the light source cannot be increased. , 121109.doc 200807137 The optical power of the beam can be increased by using an additional light source. However, it is limited to the extent to which the optical power and brightness of the beam can be increased by simply adding more light sources. The optical system that directs the beam toward the target accepts only light within a specific aperture and cone angle. These limitations depend on various factors such as the size of the lens and the f-number of the optical system. Adding more light sources does not provide an infinite increase in the power or brightness of the beam, since the greater the number of light sources, the smaller the light from a source of light (4) will be within the aperture and cone angle limits of the optical system. The present invention is applicable to the use of a plurality of light sources (such as photodiodes) having a relatively low brightness to produce a concentrated light source having a relatively high brightness. Light from a lower-brightness source is used to optically illuminate a volume of glory material. The glory material absorbs the light emitted by the low-light production: Shield Guafan Jiuyuan and emits light of different wavelengths in a fluorescent manner. Fluorescence is usually emitted isotropically by a fluorescent material. At least some of the fluorescent light can be directed within the volume to a light extraction region. The pump surface area is a fluorescent volume for coupling relatively low brightness, short wavelength pump light to the area in the volume' and the extraction area is the area from which the fluorescent volume is extracted for fluorescence. When the (iv) surface area is sufficiently large compared to the extraction area, a net increase in brightness can be achieved. In the following description, the term fluorescing encompasses - material absorption - light of a first wavelength and then emits a light of a second wavelength different from that of a wavelength of a ray. The emitted light can be combined with a single worker's spot 6 /, a neutron force for each transition or a quantum mechanical non-permissible transition (four). The latter is usually fed with a phosphorescent 1 fluorescent material that absorbs only a single pump after emitting fluorescence. For photons, the fluorescence usually has a longer wavelength than the pump light. However, in some fluorescent systems, more than one pump photon can be absorbed after the emission of fluorescence 121109.doc 200807137, in which case the emitted light can have a shorter wavelength than the pump light. This phenomenon is often referred to as up-conversion fluorescence. In some other fluorescent systems, light is absorbed by one of the luminescent materials and the resulting energy is transmitted non-radiatively to one of the materials, and the far second material emits light. As used herein, term fluorochrome and fluorescein is intended to encompass a system in which pump light energy is absorbed by a substance and the energy is re-radiated by the substance or another substance. A device of this type is illustrated and described in U.S. Patent Application Serial No. 11/092,284. 1A, 1B, and 1C schematically illustrate a particular embodiment of the present invention, and FIGS. 1A, 7(7) and 1c show top, cross-sectional and side views, respectively, of a volumetric fluorescent unit (or 2) system 100. The volumetric fluorescent unit (or illumination system) 100 has a body containing a fluorescent material, a plurality of light emitters 1 〇 4 that emit light into the body 102, and light emitted from the body 1 〇 2 Reflected back to the outer reflector 115 in the body 102. The outer reflector is spaced apart from the body 102 by a specific distance to form gaps 216A and 2ΐ6β. Figure 1A, _ and Figure provide a Cartesian (10) (four) coordinate system to help describe the volumetric fluorescent unit 1〇〇. The direction of the coordinate system has been assigned to cause the output fluorescence to propagate generally along the z-direction (having a length L) parallel to the longitudinal scale of the body. The width (w) of the body 1 〇 2 is measured in the χ direction and the height (h) of the body 102 is measured in the 戌 direction. Note that body 102 tapers along its length. In the current embodiment (best illustrated in Figure 1C), the height (h) of the body in the direction > / m) / σ direction is along the length (L) of the body 102 (i.e., along the z direction) ) Increase the size. In this embodiment, the i-pu light passes through the (four) surface (four) into the body 121109.doc •10-200807137 102 and the fluorescent output i〇9 exits the body 1〇2 through an extraction surface 112. The external reflectors 115A and 115B (integrally, the external reflector 115") are positioned directly adjacent to the non-extracting surfaces 113A to 113D (collectively referred to as "non-extracting surfaces 113M"). The pump surface i i is also a non-extracted surface 丨13. While four non-extracting surfaces 113 are illustrated in the current embodiment, it will be appreciated that any number of non-extracting surfaces 113 and any number of pumping surfaces 110 are included in the present invention. Moreover, while the outer reflectors Α5Α and 115B are disposed adjacent to the non-extracting surfaces 113A and 113C, it is contemplated that all of the non-extracting surfaces 113 can be utilized with the outer reflector 115. In the current embodiment, the non-extraction surface 113 extends along the length L of the body 102. In the illustrated embodiment, the body 102 is tapered such that the largest cross-sectional area of the body occurs at the extraction face I. At the office. A back side 150 is also illustrated and the back side 150 may or may not be orthogonal to one or more of the non-extracting surfaces 113 and may or may not be substantially parallel or substantially parallel to the extraction surface. Some of the fluorescence exiting the body 1〇2 through the extraction surface 112 (illustrated by the ray 109A) can exit the body 102 directly without reflection at any surface of the body 1〇2. The other portion of the output fluorescent light 1 (illustrated by light 109B) may have been reflected by the process of total internal reflection (HR) within the body 1 〇2. Additionally, portions of the fluorescent light (illustrated by light 108A) may be transmitted through the non-extracting surface 113A of the body 102. The other portion of the fluorescent light (illustrated by light 108B) is reflected within the body 1〇2. There are several practical reasons for leaving the gaps 216A and 216B (collectively referred to as "gap 216") between the outer reflector 115 and the body 102 rather than directly aligning the reflector Π5 with the body 102. 121109.doc -11 - 200807137. - The main reason is that the gap 2i6 allows for efficient TIR conditions. The residual loss of TIR reflections can be very low (less than 0.1% per reflection). As discussed further below, this tir effect is due to the high refractive index material of the body 102 moving low. A refractive index material (e.g., air having a refractive index of approximately 1. G.) is created by creating a gap 216, a low refractive index material such as air (or other material) can fill the gap 2! 6. Using the TIR effect It is preferable to place the reflector 115 directly against the body ι2, because unless the reflectivity of the reflector is very high at various angles, it will increase the total loss after many of the reflections required to reach the end of the body 102. Furthermore, coating the side of the body with a reflective surface would be expensive because the coating would need to be very close to the body edge and have a reflectivity of >995% (for one Many layers are required for dielectric stack reflectors, and coating all non-extracted faces will require multiple coating cycles.) Consider that the light generated within the fluorescent body 102 is reflected (through TIR) in the body 1〇2 or The range of angles of escape from body 102 is useful. Referring now to Figure 1C, consider the luminescence-generating light at point X. A particular angle at non-extracted surface 113A can be calculated from the following statement:

Ocp^sin'^rip/n) ^ (5) where nP is the refractive index outside the non-extracted surface U3A (in this case, in the gap 216A) and η is the refractive index of the body 1〇2. This angle is the usual "critical angle". The shaded area 117 shows a range of angles less than %. If the non-extracting surface 113 is in the air (i.e., if the substance filling the gap 216 is air), the value of ηρ is approximately equal to one. If light propagating from point X (e.g., ray 208 Β) is outside the cone indicated by shaded area 117 121109.doc -12-200807137, then ray 208B is totally internally reflected by non-extracting surface 113A. Therefore, in order to reduce the amount of light lost through the non-extraction surface 113A (i.e., to reduce ecp), it is generally preferred that the value of η is large. If light (eg, 'light 2 0 8 A) is incident on the non-k-take surface 113 而 and forms an angle (the incident angle, or AOI) with a line perpendicular to the non-extracted surface and the angle is less than the critical angle ( 0cp), then light 208A is transmitted through non-extracted surface U3A. In the case where external reflector 115 is added, this light (illustrated by light 208A) can be recaptured. Fig. 1D is a schematic view showing how the light unit 1 之一 of one example is performed (for clarity, it will be explained without a light emitter). Light ray 208C that does not initially satisfy the TIR condition is reflected from outer reflector 115. After being reflected and re-entered through the non-extraction surface 113 A, it has a larger AOI at the bulk y air interface at the non-extraction surface 113C than when it interacts with the bulk/air interface at the previous non-extraction surface 113A. AOI, and closer to TIR. For the illustrated ray 208C, the ray 208C is reflected several times on the external reflector 117 before the ΑΟΊ has changed enough to satisfy the tir condition in the body 1 〇 2 and the ray 2 0 8 C is transmitted therebetween. Pass through the body 102. Once the TIR is reached (shown at point 212), light 208C is confined within body 1〇2 until it reaches extraction surface 112. To more clearly illustrate this process, one of the circles defined by a circle labeled "1 e" of Figure 1D has been enlarged to Figure 1E. Again, light 208C encounters a non-extracted surface 113A at point 214A. One of the path defined by the ray 208C and the non-extracted surface 113 穿过 passes between the normal 215 of the point 214. When the ray 208C enters the gap 216, it is deflected away from the normal. Gap 121109.doc -13· 200807137 216A Is the space between the outer reflector 115 and the non-extracting surface U3A. The light 208C is reflected by the outer reflector 115 at point 214B. The light 2〇8c re-enters the body 102 at point 214C, producing a refraction angle (θι) The angle of incidence of light 208C at point 214 实质上 is substantially opposite to its angle of refraction at point 214C. Light ray 208C travels through body 1〇2 until it encounters a non- & surface 113C at point 214D. 208C defines a ΑΟΙ^+η which is larger than the AOI at points 214A and 214C. This is due to the non-parallel relationship between the normal 215A at the non-extraction surface 113A and the normal 215B at the non-extraction surface U3C. The skew relationship between the normals (215A and 215B) is Non-parallel relationship on the side of the tapered body 102. When the light 2〇8C leaves the unknown: take the surface 113 A or the non-extraction surface 113 c, and enter the gap 2 16 A or 216B 'AOI with the light 208C The AOI is then sufficiently large that it is greater than the critical angle, and the ray 2〇8C begins to exhibit TIR within the body 102, such as at point 212. As illustrated in Figure 1F, some of the backwards that initially satisfy the TIR condition are shown. The propagating light (i.e., the light propagating in the direction of the narrowed portion of the body 1 〇2 as illustrated by the light 208D) (because the AOI of the light falls below the critical angle) is eventually coupled out from the side of the plate. In an embodiment, when the light 2〇8D encounters the non-extracted surface 113A or 113C, it initially has an AOI greater than the critical angle, but after each reflection from the non-extracted surface 113A or 113C, the angle of incidence decreases. The appearance of the ray 208D is opposite to the ray 208C (discussed previously with respect to Figure 1E). Since the ray 2 〇 8D does not reach the end of the body 102 before its ao is reduced below the TIR angle, its self-property 102 goes out (such as At point 214E, the addition of external reflector n5 prevents 121109.doc -14· 200807137 from loss of light 208D. After loss of TIR, light 2〇81) is reflected from external reflector 115, and when light 208D is not extracted When the surface 113A or 113C leaves the body 102, it has a gradually smaller AOI after each reflection until the AOI passes through zero degrees (rotated) and starts in the forward direction (ie, toward the extraction surface). 112 and propagates in the direction of the widened portion of the body 102. Light 208D is then advanced as shown in Figure 1D, eventually returning to the TIR within body 102 and being extracted from extraction surface Π2. As illustrated in Figure 2, the light unit (or illumination system) 3 (10) includes an external reflector 315 that can be used with a body 3〇2 having at least a portion that is not tapered. For the sake of clarity, Figure 2 is a schematic illustration of a light unit 300 that is not present without a light emitter. In this case, reflector 315 limits light 308C that does not satisfy the TIR condition (i.e., A 〇 I is not greater than the critical angle) until ray 308C is coupled into tapered portion 320. The outer reflector 315 can be erected parallel to the non-tapered portion 324 of the body 302 and the non-extracting surfaces 313A and 313B of the tapered portion 320 (in other words, the reflector 3 15 is "tiled"). In another embodiment illustrated in Figure 3, the outer reflector 415 can have a single slope relative to the entire body 3〇2, including the tapered portion and the non-tapered portion 324. For convenience of description, the transition point between the tapered portion 320 and the non-tapered portion 324 will be referred to as a non-conical wheel end 326 and a tapered input end 328. Please understand that this is an arbitrary reference, and or 'this point can, for example, refer to the non-tapered portion of the " extraction surface, t. As illustrated in Figure 2, the ray 308C of the escaping body 3〇2 (due to an AOI less than the critical angle) is continuously reflected by the reflector 315 and when it exits the body into one of the air gaps 316A or 316B, The AOI propagates through the body 302 without substantially changing 121109.doc -15 · 200807137. Light ray 308C does not begin to approach the TIR condition until it encounters tapered portion 320. This is due to the fact that the normals illustrated by 322A and 322B on the opposite non-extracted surfaces 313 A and 3 13B at the non-tapered portion 324 are substantially parallel. The result is that the AOI of light 308C does not change significantly. After light 308C enters tapered portion 320, the normals illustrated by 322D and 322E become skewed, and when light 308C encounters non-extracted surfaces 313A and 313B, its AOI changes until light 308C reaches TIR (eg, Shown at point 212A). This process is equally applicable to the light unit (or illumination system) illustrated at 400 in Figure 3, although the external reflector 415 has a single slope for the length of the body 302. As indicated, normals 422A and 422B are substantially parallel, while normals 422C and 422D are skewed such that light 408C enters the D1 condition (shown at point 412) after entering the tapered portion 320 of body 302. The tapered portion 320 of the body 302 additionally has the advantage of acting as an output extractor that reduces the amount of fluorescence that would otherwise be totally internally reflected at the extraction surface 312 (as opposed to using a non-conical body). To form the tapered body 302, different types of tapered portions 320 in the form of output extractors can be coupled to the non-tapered portion 324. In one such manner, a tapered, transmissive rod or tunnel is coupled to the non-tapered output 326 for use as an output extractor and forms a tapered portion 320 of the body 302. The tunnel is shaped to be tightly coupled to the non-tapered output 326. If the non-tapered output 326 is sufficiently matched to the extractor (i.e., the size, shape, and index of refraction are matched), then the tapered input end 328 can be offset against the non-tapered output 326 or at a less than non-tapered output. One of the wavelengths 326 (preferably about or less than a quarter of a wavelength) is placed to efficiently illuminate light from the non-tapered 121109.doc -16 - 200807137 portion 324 into the tapered portion 320. An index matching material (e.g., a refractive index matching oil or an optical adhesive) may also be used between the extractor and the split/output 326. The extractor can be made of any suitable transparent material, such as glass or a polymer. The reflection of the fluorescent light in the extractor tends to direct the fluorescent light along the z-direction, and thus the angular spread at the output end of the fluorescent money channel (i.e., the extraction surface 312) is small; the light from the non-tapered portion 324 The angular spread when entering the conical portion 32〇. Less

The angular spread of the eve is reduced at the output end surface (i.e., the amount of fluorescent light that is totally internally reflected by the extraction surface 31. The tapered portion 320 may be integrally formed with the non-tapered portion 324, for example, from a single A piece of material, such as a polymeric material, molds the tapered portion 32 and the non-tapered portion 324. Further, the tapered portion 32() may or may not contain a fluorescent material. The extraction face 312 of the tapered portion 320 may be perpendicular to 2 axes, or tiltable, for example, as further described in the published U.S. Patent Application Serial No. (^^丨), pp. 丨 。. The oblique extraction surface 312 can be useful, for example, by an image relay The system images the extraction surface 312 to a tilt target. One example of a tilt target is a digital multi-mirror device (DMD), and one example of a digital multi-mirror device is from Plano, Texas (7).

Texas Instruments is supplied by Texas Instruments, such as the DLPTM imager. A dmD has a number of mirrors positioned in a plane, each of which can be individually addressed to tilt between two positions. The DMD is typically illuminated by a beam that is not perpendicular to the DMD mirror plane (ie, the mirror plane is tilted relative to the direction of illumination light propagation), and the image light reflected by the DMD is in a direction perpendicular to the mirror plane. reflection. 121109.doc • 17- 200807137 The body of the present invention can take many different shapes. In the exemplary embodiment illustrated in Figures 3 to 3, body 102 has a rectangular cross section parallel to the x_y plane. In other exemplary embodiments, the cross section of the body (1〇2, 3〇2) may not be J5] 'Example #' may be rounded, triangular, elliptical or polygonal, and may also be irregular. Please note that the cross-sectional area of the body 102 illustrated in FIGS. 1A-1F (in the py plane) and the tapered portion 320 in FIGS. 2 and 3 may be increased in only one dimension or two dimensions (ie, , f, cone may appear. For purposes of illustration, the reflectors ι 5, 315, and 415 shown in Figures 3 through 3 include an air gap. In an actual design, it is preferred to keep the air gap small. Keeping the gap small minimizes the light escaping from the side of the reflector. For a significant improvement in extraction efficiency, the air gap is preferably smaller than the width of the body 102, 302 at its small end. For typical designs, this Means that the air gap is less than 1 μm. Although the space a is a typical object f in the gap, the present invention contemplates the use of other materials such as a dielectric having a low refractive index compared to air. Or the filling gap of the gas 216. Another reason for keeping the gap small is that it is in the fluorescent material due to Stoke from the excited state (Me0 displacement (difference between input energy and fluorescent photon energy) and non-radiative decay Produces heat. Many fluorescent materials exhibit thermal quenching Reduction effect: wherein when the temperature increases, the fluorescence quantum efficiency decreases (that is, the generated light decreases). χ, it is desirable to control the temperature of the working body to prevent possible damage to the material and structure. Forced air cooling can be problematic because dust and other contaminants from the air can accumulate on the surface of the body and increase the loss of light reflected from the surface of the table 121109.doc 18 200807137. In addition, the poem that can be achieved by the fan The forced air convection heat transfer coefficient of air velocity is in the range of 6 to 30 w/m2 * κ. This may be lower than the coefficient required to achieve the desired result. Cooling by direct mechanical contact of the side of the plate to a heat sink The tir process will be disturbed by the elimination of the low refractive index material (air) as previously discussed. The small air gaps 416A and 416B in Figure 4A are maintained between the surface of the body 402 and the reflector 415 to allow for heat to be tolerated. TIR will occur when transferred to the heat sinks 430A and 430B. The heat sink (43〇A & 43〇B) can be cooled in a conventional manner, for example, by direct air or by combining heat pipes or liquids. Heat transfer air. The thickness of the gaps 416A and 416B can be selected to ensure that the thermal resistance of the material layer (e.g., air) in the gaps 416A and 41 6B does not exceed the heat transfer requirements. Gases other than air (or other materials) can be used. Filling gaps 416A and 41 6B, especially those having a higher thermal conductivity than air, such as the materials in the following table: Gas thermal conductivity (W/m K) Air 0.024 N2 0.024 He 0.143 Ne 0.046 The gas in the gap may be at a pressure above atmospheric pressure which may further increase the thermal conductivity. By combining the reflector 415 with the heat sinks 430A and 430B, and maintaining the gaps 416A and 416B in the body 402 and the reflector Between 415, the effectiveness of light output can be increased. This occurs due to: the loss of TIr light reduction (when using a tapered body in 121109.doc -19- 200807137), the potential for light absorption due to light from the light emitter that can be directed into the panel Increase, and control the temperature of the body 4〇2 to limit the quenching. The thermal resistance between the body 4〇2 and the ambient air can be controlled by controlling the gap between the body 402 and the heat sinks 430A and 430B (and more specifically the reflector 415), and thus the body 402 is controlled temperature. In a preferred embodiment, the distance between the gaps 416A and 416B is maintained at 1 〇〇 micron or less. Other preferred gap distances include distances of 0.075 mm and 〇·03 mm. Light emitter 404 (e.g., a light emitting diode, or LED) is illustrated as a pump >#light' source for illuminating body 4〇2. These light emitters 404 are illustrated as being attached to heat sinks 430C and 430D. Additional reflective surfaces may be attached to the heat sinks 43C and 430D or placed between the light emitter 404 and the body 402 to further inform the body 402 for cooling. It may be useful to have such reflective surfaces dichroic to allow the pump to pass through the reflector while reflecting the fluorescence. The invention includes cooling the body 402 with a minimum gap distance between the body 402 and the reflector 415, regardless of whether the body 402 is tapered (or includes a tapered portion) or non-tapered. One embodiment of the present invention utilizes a curved reflector 515A, as shown in Figure 4B. Although the curved reflector is shown to contact the body 5 02 ' on only one edge, a curved reflector that contacts the body on the edges of the two reflectors (as shown in the dashed line at 5 1 5B) can be provided. Note that in the illustrated embodiment, the reflector 5 1 5 A is primarily a reflector for directing pump light generated by the light emitters 5〇4, while the reflector 515B is primarily used for reflections. Fluorescent (as previously discussed and described). If reflectors 5 15 A and 121109.doc -20- 200807137 515B are used at the same time, reflector 515B will preferably be dichroic, allowing light from light emitter 504 to pass through while reflecting from body 502. Fluorescent. The curved reflector configuration provides a different airflow space that may be desirable when designing a cooling system for the light unit of the present invention. Light emitter 504, reflector 515, gap 516, and heat sink 530 are also illustrated. Although the discussion of the advantages of placing the reflector in close proximity to the body is discussed primarily in the context of regenerative loss of TIR light, it is also understood that the reflector can be used to limit pump light and fluorescence. If the external reflector is placed on all sides of the body, that is, between the light emitter and the body, it can be beneficial to make the reflector dichroic, so that the pump light can be minimized. Pass under. Referring again to Figures 1A through 1C, it is noted that the particular choice of phosphor material will depend on the desired wavelength of the phosphor and the wavelength of the light emitted from the light emitters 112. Preferably, the phosphor material efficiently absorbs the pump light 106 emitted by the light emitters 〇4 such that most, if not all, of the pump light 〇6 is absorbed within the body 102. This enhancement converts the pump light 1〇6 into a useful fluorescent output 10 9 efficiency. The light emitter 104 can be any suitable type of transmitting incoherent light. The invention is particularly useful for generating a relatively bright beam of light using light from a less bright light emitter. In a preferred exemplary embodiment, the pupil (8) emitted from the light emitter 1 〇 4 is in a wavelength range that is well overlapped with the absorption wavelength band of one of the phosphor materials. Again, the following is useful if the light emitter 104 can be oriented such that there is a high degree of optical coupling of light 100.6 emitted by 121109.doc -21 - 200807137 to the body 102. A suitable type of light emitter is an LED which typically produces light 1 〇 6 having a bandwidth in the range of about 2 〇 nm to about 50 nm, although the optical bandwidth can be outside this range. Moreover, in many cases, the radiation pattern from an LED is generally of the Lambertian type, and thus it is possible to consume light 1〇6 into the body 102 relatively efficiently. Other types of light emitters can also be used, such as gas discharge lamps, incandescent lamps, and the like.

Light emitters 1〇4 (shown by dashed lines at 22 视) may be provided on a substrate as desired. For example, if the light emitters 1〇4 are LEDs, the substrate 220 can be electrically and thermally coupled to the LEDs to provide power and cooling, respectively. The substrate 220 can be reflective such that some of the light (illustrated by the light 1 〇 6 A) from the light emitter 104 in the direction away from the body 1 可 2 can be redirected toward the body 102. In addition, the substrate 22 can reflect pump light that has passed through the body 102 without being absorbed (illustrated by light 1). The maximum efficiency of coupling fluorescence from a body using total internal reflection can be calculated. As noted above, it is generally preferred that the body have a higher index of refraction to allow a greater proportion of fluorescent light to be totally internally reflected within the body. Body 102 can be formed from any suitable material. For example, body 1 (10) may be formed from the phosphor material itself, or may be formed from some dielectric material that transmits fluorescent light and contains a light-emitting material. Some suitable examples of dielectric materials include (4) machine crystals, glass, and polymeric materials. Some examples of fluorescent materials that can be doped into the dielectric material include 豨+i rare earth ions, transition metal ions, organic dye molecules, and phosphors. One suitable type of dielectric boat and fluorescent material includes inorganic crystals doped with rare earth ions, such as ytterbium-doped Ji Ming Shi Quanshi 121109.doc •22-200807137 (Ce:YAG), or transition metal ions Doped inorganic crystals, such as chrome-doped sapphire or titanium-doped sapphire. Rare earth ions and transition metal ions can also be doped into the glass. Another suitable type of material includes a fluorescent dye that is doped into a polymer. Many types of fluorescent dyes are commercially available, for example, from Sigma-Aldrich of St. Louis, Missouri, Missouri, USA, and Exciton, Inc. of Dayton, Ohio, USA. Common types of fluorescent dyes include luciferin; rhodamine, such as rhodamine 6G and rhodamine B; and fragrant ruthenium, such as coumarin 343 and coumarin 6. The specific choice of dye depends on the desired wavelength range of the fluorescent light and the wavelength of the pump light. Many types of polymers are suitable as the bulk for the fluorescent dyes including, but not limited to, polydecyl methacrylate and polyvinyl alcohol. The filler includes particles of a crystalline or ceramic material comprising a fluorescent material. Phosphors are typically included in a matrix, such as a polymeric matrix. In some embodiments, the refractive index of the substrate can substantially match the index of refraction of the fill (within φ at least 0.002) to reduce scattering. In other embodiments, a phosphor may be provided as a nanoparticle within the matrix: there is little light scattering within the resulting matrix due to the small size of the particles, even if the refractive index is not well matched. • Other types of fluorescent materials include doped semiconductor materials such as • doped π-γι semiconductor materials such as zinc telluride and sulfide. An example of an up-converting phosphor material is the recorded doped ceraphanite glass described in more detail in commonly-owned U.S. Patent Publication No. 2004/003753, filed on Jan. In this material, two, three or even four pump photons are absorbed by the erbium ions (Tm3+) to excite the ions to the different excitations that subsequently emit fluorescence. 121109.doc -23- 200807137. The examples of the luminescent materials described above are presented for illustrative purposes only and are not intended to be limiting. An illustrative embodiment of a projection system that can use a fluorescent volumetric light unit as described herein is schematically illustrated in FIG. In this particular embodiment, projection system 500 is a three-panel projection system having different colored illumination beams 506a, 506b, 506c (e.g., red, green, and

Light beams 502a, 502b, 502c of blue light beams. In the illustrated embodiment, green light source 502b includes a fluorescent volume light unit. However, any or all of the light sources 502a, 502b, 502c may include a fluorescent volume light unit. Light sources 502a, 502b, 502c may also include beam directing elements (eg, mirrors or ridges) to direct any of colored illumination beams 506a, 5〇6b, 5〇6c to their respective imaging devices 5〇4a, 504b, 504 e.

Imaging devices 504a, 504b, 504c can be any type of imaging device. For example, imaging devices 504a, 504b, 504c can be transmissive or reflective imaging devices. Both transmissive and reflective liquid crystal display (LCD) panels can be used as imaging devices. An example of a suitable type of transmissive LCD imaging panel is a high temperature polycrystalline lithotripe (HTPS) LCD. An example of a suitable type of reflective lcd panel is an on-silicon liquid crystal (LCoS) panel. The LCD panel modulates an illumination beam by polarization-modulating the light associated with the selected pixel, and uses a polarizer to separate the modulated light from the unmodulated light. Another type of imaging device, known as the Digital Multiple Mirror Device (DMD) and supplied by Texas Instruments of Plano, Texas, under the trade name DLPTM, uses an individually addressable mirror. The mirrors deflect the illumination light toward the projection lens or away from the projection lens. In the embodiment illustrated in 121109.doc -24-200807137, the imaging devices 504a, 504b, 504c are of the LCoS type. The light sources 5 02a, 502b, 5 02 c may also include various elements such as polarizers, illuminators, lenses, mirrors, and the like for trimming the light beams 506a, 506b, 506c ° color illumination beams 506a, 506b And 506c are guided to respective imaging devices 50A, 504b, and 504c via respective polarized beam splitting mushrooms (PBS) 5 10a, 5 10b, and 510c. Imaging devices 504a, 5A, and 5" polarization modulated incident light beams 506a, 506b, and 506c such that individually reflected color image beams 508a, 508b, and 508c are separated and transmitted by PBSs 510a, 51〇b, and 510c. To color combiner unit 514. The color image beams 508a, 508b, and 508c can be combined into a single, full-color image beam 516 that is projected by a projection lens unit 511 onto the screen 51. The imaging devices 504a, 504b, 504c can be coupled to a controller 52 (dashed line) that controls the image displayed on the screen 512. The controller can be, for example, an adjustment and image control circuit for a television, computer or the like. In the illustrated exemplary embodiment, color illumination beams 5, 506b, 506c are reflected by PBSs 510a, 5 10b, and 5 10c to imaging devices 5〇4a, 504b, and 504c and resulting image beams 508a, 5〇81> And 5〇8 (: transmitted through PBS 51〇a, 510b & 51〇c. In another method not illustrated, illumination light can be transmitted through the PBS to the imaging device, and image light is reflected by the PBS. Other implementations of the projection system A different number (a larger number or a smaller number) of imaging devices may be used. Some embodiments of the projection system use a single imaging device' while other embodiments employ two imaging devices. For example, make 121109.doc -25 - 200807137 A projection system using a single imaging device is described in more detail in co-owned patent application Serial No. 10/895,705, and a projection system using two imaging devices is described in co-owned U.S. Patent Application Serial No. 1/914,596: In a single-panel projection system, illumination light is incident only on a single imaging surface. • The incident light is modulated so that only one color of light is applied to the portion of the imaging device. With Over time, the color change of the light that the person hits the imaging device 'for example' changes from red to green to blue and then back to red to repeat the loop. This is often referred to as "field color" Operating mode. In other types of single-panel projection systems, different colored strips of light can be scrolled onto a single panel so that the panel is illuminated by an illumination system with more than one color at any time, but on the panel Any particular point is only illuminated by a single color. In a two-panel projection system, two colors are sequentially directed to a first imaging device panel. The first imaging device panel sequentially displays a shirt matching the two colors. A panel is usually illuminated by a third color of light. The image beams from the first and second panels are combined and projected. Due to the integration in the eye, the viewer sees one. Full-color image. Example • As a theoretical example, consider a ce:YAG tapered body with a refractive index of 1.835. The body is 50 mm long and the cross section at the small end is The cross section at 0.5 mmx〇.89 mm and the large end (continuous taper) is 1.65 mm x 2.93 mm. The front 22 mm of the body is excited by a blue LED to generate fluorescence. The efficiency of light extraction produces fluorescence along the body. The 22 mm change. Figure 6 illustrates the efficiency as a function of position (the amount of light extracted from the extraction surface 121109.doc -26- 200807137 versus the Ipu light), in which the - Two external reflectors on the two large faces of the body produce fluorescence for the body. The efficiency of the forward light is constant before about 16 mm, at 16 mm, the part of the light is on the plate The output end face experiences TIR. The rate of light that is made backwards continues to decrease from the end of the plate. This reduction is due to the gradual increase in loss of light from/on both sides of the reflector. Figure 6 also shows the comparison of the body without the reflector. The extraction efficiency as a function of the plate position (the plate with external reflection on all four sides) is shown in FIG. In this case (assuming that the inverse, k) is taken at the point of 16 mm, at the point of 16 mm, the TIR begins to appear on the exit face. For comparison purposes, the condition of not using a reflector is included. In practical systems, the improvement in extraction efficiency will be limited by the reflectivity of the external reflector. Figure 8 illustrates the effect of the calculated reflectance reduction of the external reflector. For reflectances above 95% (within the relatively simple range of enhanced metal reflectors), a substantial increase in efficiency is achieved. This is an extremely rapid drop in efficiency in this situation compared to the situation where a reflector is placed directly on the board and requires greater than 99% reflectance for any enhancement. Example For an illustrated board having dimensions of 60 χ 1 · 46 χ 2 · 6 mm, the board has 90 LED dies each powered by 3 W and assumes 15% of the LEDs to the light conversion and board The 15% of the Stoke loss in the 'the heat generated inside the board will be about 6.1 W (= 3Wx9〇x〇.15x〇.15). The two large sides of the plate have a surface area of 3 · 1 cm2. , 121109.doc -27- 200807137

If the plate temperature is not more than 15 °C and the ambient air temperature will be 45 C, the heat transfer needs to exceed ip W/m2*K __6:1 W__w

3.1cm2 (150~45) Κ ^187m2K, the maximum thermal resistance will be 17TK/W (1〇5/61). The heat sink (for example, UBC60_25B from Alphanovatech®, with forced air convection at 2 m/sec) will have a thermal resistance of approximately 9 〇k/w.

Therefore, the thermal resistance of the air gap must not exceed 8·2 〇ΚΛν (ie, 17.2-9). The calculation of the thermal resistance of the air gap as shown in Figure 9 confirms that an air gap of less than 〇〇75 will be sufficient to cool the plate as needed. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1A, FIG. 1B, FIG. 1D, FIG. 1E, and FIG. 1F schematically illustrate an embodiment of a volumetric fluorescent unit in accordance with the principles of the present invention; FIG. 2 schematically illustrates a Another embodiment of a volumetric fluorescent unit having a portion of a tapered body and a tiled reflector in accordance with the principles of the present invention; FIG. 3 is a schematic illustration of a portion of a tapered body and non-tiled reflection in accordance with the principles of the present invention. Another embodiment of a fluorescent body of the device; FIG. 4A schematically illustrates an embodiment of a volumetric fluorescent unit having a reflector and a heat sink in accordance with the principles of the present invention; FIG. 4B schematically illustrates - in accordance with the present invention Embodiment of a volumetric fluorescent unit having a curved reflector and a heat sink; schematically illustrating - using one embodiment of a projection system of a volumetric glare unit in accordance with the principles of the present invention; Graph of extraction efficiency at various distances of the small end of the body of the volume fluorescent unit 121109.doc -28- 200807137; Figure 7 shows various distances from the small end of the body of an experimental volume fluorescent unit Extraction efficiency graph; Figure 8 shows a graph of the relationship between extraction efficiency and the external mirror reflectivity FIG.;. And, Figure 9 shows a graph of thermal resistance of a variety of air gap distance. The same numbers in different figures refer to like elements. While the invention may be susceptible to various modifications and alternative forms, However, it should be understood that the invention is not limited to the specific embodiments described. Rather, the invention is to cover all modifications, equivalents, and alternatives of the invention as claimed. [Main component symbol description] 100 volume fluorescent unit (or illumination system) 1〇2 body φ 104 light emitter 106 light 10ΒΑ light. 108Β light 108C light, 1〇9 fluorescent output 109Α light 109Β light 110 pump surface 121109 .doc -29- 200807137

112 Extraction face 113 Non-extraction surface 113A Non-extraction surface 113B Non-extraction surface 113C Non-extraction surface 113D Non-extraction surface 115 External reflector 115A External reflector 115B External reflector 117 Shadow area 150 Back surface 208A Light 208B Light 208C Light 208D Light 212 points 212A Point 214A Point 214B Point 214C Point 214D Point 214E Point 215 Normal Line 215A Normal Line 121i09.doc •30 200807137

215B normal 216 gap 216A gap 216B gap 220 substrate 300 light unit (or illumination system) 302 body 308C light 312 extraction surface / extraction surface 313A non-extraction surface 313B non-extraction surface 315 external reflector 316A air gap 316B air gap 320 cone Portion 322A Normal 322B Normal 322D Normal 322E Normal 324 Non-tapered portion 326 Non-conical output 328 Conical input 400 Light unit (or illumination system) 402 Body 121109.doc -31- 200807137

404 light emitter 408C light 412 point 415 external reflector 416A air gap / gap 416B air gap / gap 422A normal 422B normal 422C normal 422D normal 430A heat sink 430B heat sink 430C heat sink 430D heat sink 500 projection system 502 Body 502a light source 502b light source 502c light source 504 light emitter 504a imaging device 504b imaging device 504c imaging device 506a illumination beam 121109.doc 200807137 506b illumination beam 506c illumination beam 508a reflected color image beam 508b reflected color image beam 508c reflected Color image beam 510a Polarized beam splitter (PBS) 510b Polarized beam splitter (PBS) 510c Polarized beam splitter (PBS) 511 Projection lens unit 512 Screen 514 Color combiner unit 515 Reflector 515A Curved reflector 515B Reflector 516 Gap/image beam 520 controller 530 heat sink h south degree L length X point w width 121109.doc -33-

Claims (1)

200807137 X. Patent application scope: 1 · An illumination system comprising: an incoherent light source capable of generating light in a first wavelength range; a narrow body 'when illuminated by light in the first wavelength range Transmitting light in a second wavelength range, the body having a length dimension, a visibility dimension, and a height dimension, at least a portion of the body being tapered to increase width and/or height along the length dimension, the body further An extraction surface and a first non-extraction surface extending along at least a portion of the length of the body and disposed to share a common edge with the extraction surface; wherein the second wavelength At least a portion of the light is totally internally reflected at the non-extracting surface; and at least one external reflector disposed proximate the non-extracting surface to create a gap between the outer reflector and the non-extracting surface. 2. A system as claimed, wherein the incoherent light source is disposed in a different location than the location between the outer reflector and the non-extracting surface. 3. The system of claim </ RTI> wherein the gap between the outer reflector and the non-extracted surface is substantially filled with a fluid. 4. The system of claim 3, wherein the fluid is air. 5. The system of claim 1, further comprising: - a second non-extracting surface disposed on the side of the body opposite the first non-extracting surface; 121109.doc 200807137 a second external reflector, And the female is placed adjacent to the second non-extracting surface to create a gap between the outer reflector fish/, a non-extracting surface of the brother, wherein the incoherent light τ is placed in a different In the first external reflector and the first-non-媳6. Le Yi is not in the position of the position between the surface. The illumination system of claim 5, further comprising: a third non-extracting surface on the body; a fourth non-extracting surface on the body disposed on one of the body and the third non-extracting surface Opposite the side surface and substantially perpendicular to the first non-extracting surface; a third outer reflector disposed adjacent to the third non-extracting surface for between the outer reflector and the third non-extracting surface A gap is created, wherein the incoherent light source is disposed at a different one than the third. The position of the position between the 卩 reflector and the third non-extracting surface; and Brother four. a 卩 reflector disposed adjacent to the fourth non-extracting surface to create a gap between the outer reflector and the fourth non-extracting surface, wherein the incoherent light source is disposed at a different one than the fourth In the position of the position between the reflector and the fourth non-extracting surface. The illumination system of the first item 1 has a distance of less than 1 〇 微米 micrometer. The knowledge of the term 1 is that the cross section of the body is usually a rectangular shape. 9. The illumination system of claim 1, wherein the reflector extends substantially parallel to the non-extracting surface. The system of claim 1, wherein the reflector has a concave surface on one side of the non-extracting surface. U. The system of claim 1, wherein the body comprises a phosphor material that emits light in a second wavelength range different from the first wavelength range. 12_ The system of claim </ RTI> wherein the at least one first incoherent light source comprises a first source and at least a second source. 13. The system of claim 12, wherein the first source and the second source are disposed on different sides of the body. The system of claim 1 wherein the first source is a light emitting diode (LED) 〇 15. The system of claim 14, wherein the LED is disposed on a reflective substrate. The system of claim 1, wherein the at least one first light source comprises a plurality of light emitting diodes (LEDs) that emit light in the first wavelength range for a plurality of months, and the Φ hai-wavelength range is It is between about 4 〇〇 nm and about 500 nm, and the wavelength range is between about 500 nm and about 600 nm. The system of claim 1, wherein the body has a surface opposite the extraction surface, the back surface being substantially parallel to the extraction surface. The system of claim 17, wherein the body has sidewalls extending between the back surface and the extraction surface, the sidewalls being substantially flat. The system of claim 18, wherein the back side is not perpendicular to at least one of the sides. 20. The system of claim 1 further comprising a tapered portion disposed at an exit of a non-conical input 121109.doc 200807137, wherein the tapered portion (four) learns to transfer the second wavelength range The light in the middle. 21. The system of claim 2, wherein the at least one reflector extends along a surface of the non-cone U-knife and the tapered portion and the gap extends between at least the split and the reflector. .22. If = 21m, the tapered portion of the towel is "lighter" to the extractor of the body. 23. If the request item 22$ would e • + , , 糸 , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , The system of 22, wherein the output extractor is formed from a material that is opposite the body and is integrally formed with the body. And wherein the body comprises a material, the material and the average free path of the light in the second wavelength range at least twice the length of the body. • 'If the body of the item 1 has a length L and a height 2, when the total internal reflection is made at the surface of the body, the ratio of scattered light is less than 5% / ( 2L/h). 27. The system of claim 1, wherein the wavelength range comprises a wavelength that is longer than the first wavelength. 28. The system of claim 1, wherein the projection unit is at least one imaging device, the projection lens unit, and a shadow from the imaging device. The imaging device, ^ is first projected by the projection lens unit 121109.doc -4 - 200807137 to the screen. 29. The system of claimants, wherein the body comprises an φ ϊ I φ, ι '4 s monthly material. The fluorescent material comprises at least one of a rare earth metal ion octagonal ion and an organic fluorescent dye. The system of the present invention, wherein the body comprises a glory material disposed in the body, the transparent material comprising one of the inorganic crystal substrates. A glass and a polymeric illumination system comprising: - an incoherent light source capable of producing light in a first wavelength range; a long body 'when illuminated by light in the first wavelength range - a second wavelength The light in the range' the body further includes an extraction: ^ and a first-non-extracted surface extending along at least a portion of the length of the body and disposed to be associated with the extraction surface a common edge; /, wherein at least a portion of the light of the second wavelength is totally internally reflected at the non-extracting surface; and at least one external reflector is disposed adjacent to the non-extracting surface for interaction with the external reflector A gap of 100 microns is created between the non-extracted surfaces. 32. The method of claim 31, wherein the gap between the outer reflector and the non-extracting surface is substantially filled with a fluid. The system of claim 32, wherein the fluid is air. The system of claim 3, further comprising: a second non-extracting surface disposed on a side of the body opposite the first non-121109.doc 200807137 extraction surface; Positioned adjacent to the second non-extracting surface to create a gap between the outer reflector and the second non-extracting surface, wherein the incoherent light source is disposed in a different state than the second-outer reflective state In the position of the position between the second non-extracting surface, 35. The illumination system of claim 31, further comprising: a third non-extracting surface on the body; a fourth non-extraction on the forest a surface disposed on a side of the body of the third non-extracted surface, substantially perpendicular to the first non-extracted surface; a third external reflector disposed adjacent to the third non-extraction a face to create a gap of less than 100 microns between the outer reflector and the third non-extracting surface; and a fourth outer reflector disposed adjacent to the fourth non-extracting surface for reflection at the outer And a gap of less than 100 microns between the fourth non-extracting surface, wherein the incoherent light source is disposed in a different position than the position between the fourth outer reflector and the fourth non-extracting surface 36. The illumination system of claim 31, wherein the body has a substantially rectangular cross section. 37. The illumination system of claim 3, wherein the reflector extends substantially parallel to the non-extracting surface. The system of claim 3, wherein the body comprises a phosphor material that emits light in a second wavelength range different from the first wavelength range of 121109.doc 200807137. 3 9. As claimed in claim 3 The system, wherein the at least one first incoherent light source comprises a first source and at least a second source. 40. The system of claim 3, wherein the at least one first light source comprises a light emitting diode (LED) capable of emitting light in the first wavelength range, the first wavelength range being between about 400 nm and about 500 nm, and the second wavelength range being about 500 nm and about 600 Between nm. 121109.doc