TW201300697A - Optical structure for a remote phosphor emitting diode - Google Patents

Abstract

The present invention generally relates to broadband solid state illumination sources and image projectors utilizing a phosphor layer or material that is pumped or energized by light from one or more LEDs. In particular, the present invention provides an effective and bright source of polarized light. This configuration is compact, efficient and has a particularly low light spread.

Description

Optical structure for a remote phosphor emitting diode

The present invention relates generally to light sources, and is particularly useful for solid state light sources incorporating light emitting diodes (LEDs) and phosphors. The invention is also related to related articles, systems and methods.

This application is related to the following U.S. patent applications incorporated by reference: "REMOTE PHOSPHOR CONVERTED LED" (Attorney Docket No. 67248US002) and "REMOTE PHOSPHOR POLARIZATION CONVERTER" (Attorney Case No. 67422US002), both applications The case was filed on the same date as the case.

Solid state light sources that emit broadband light are known. In some cases, such light sources are fabricated by coating a yellow light emitting phosphor layer onto a blue LED. When light from the blue LED passes through the phosphor layer, some of the blue light is absorbed and a substantial portion of the absorbed energy acts as Stokes shifted light (usually yellow) at longer wavelengths in the visible spectrum. Re-emitted by the phosphor. The phosphor thickness is small enough that some of the blue LED light is always passed through the phosphor layer and combined with the yellow light from the phosphor to provide broadband output light with a white appearance.

Other LED pumped phosphor sources have also been proposed. In U.S. Patent 7,091,653 (Ouderkirk et al.), a light source is discussed in which ultraviolet (UV) light from an LED is reflected onto a phosphor layer by a remote reflector. The phosphor layer emits visible light (preferably white light) which is substantially transmitted by the remote reflector. So that when UV light travels from the LED to the remote reflector The LED light, the phosphor layer, and the long pass filter are disposed without passing the UV light through the phosphor layer.

There are two main ways to increase the polarization output of a light source. One method is to position the reflective polarizer to return light having an undesirable polarization state to the light source. Assuming that the light source does not fully absorb the light and the system can change the polarization state of the light deterministically or randomly, the light will be re-emitted from the source and some of the light will pass through the reflective polarizer in the desired state. Another method is to use a polarization converter that can almost double the output of the light in the desired polarization state, but can also multiply the light spread of the illuminator.

Although polarization converters are extremely effective, they may be less valuable in systems with limited etendue. The recirculating polarizer does not substantially increase the amount of light but is limited by the reflectivity of the source. Because LEDs typically have a reflectivity of 50% and randomize the polarization state, efficiency is typically less than 15% in practical systems. There is a need for systems that effectively recycle polarized light without significantly increasing the amount of light.

The present invention generally relates to broadband solid state illumination sources and image projectors utilizing a phosphor layer or material that is pumped or energized by light from one or more LEDs. In particular, the present invention provides an efficient and bright source of polarized light. This configuration is compact, efficient and has a particularly low light spread. In one aspect, the present invention provides an illumination system including: a light emitting diode (LED) disposed on a substrate and configured to emit a first light beam in a first propagation direction such that The first beam passes through a collimating optics; a wavelength selective reflector in the collimating optics, the wavelength selective reflector for reflecting the first beam back through Passing the collimating optics; and a phosphor disposed adjacent to the LED, the phosphor capable of downconverting a major portion of the first beam to cause it to become a second beam, the second beam being in a The two propagation directions propagate back through the collimating optics and through the wavelength selective reflector.

In another aspect, the present invention provides an image projector comprising: an illumination system; a polarization converter capable of converting a second beam into a third beam having a first polarization direction; An imager positioned to intercept the second beam of the first polarization direction; and projection optics. The illumination system includes: a light emitting diode (LED) disposed on a substrate and configured to emit a first light beam in a first propagation direction to pass the first light beam through a collimating optics; a wavelength selective reflector in the collimating optic, the wavelength selective reflector for reflecting the first beam back through the collimating optics; and a phosphor disposed adjacent to the LED The phosphor is capable of downconverting a major portion of the first beam such that it becomes a second beam that propagates back in a second propagation direction to pass through the collimating optics and through the Wavelength selective reflector.

The above summary is not intended to describe each embodiment or every implementation of the invention. The following figures and detailed description more particularly exemplify illustrative embodiments.

Throughout the specification, reference is made to the accompanying drawings, in which like reference

The figures are not necessarily drawn to scale. Similar numbers used in the figures refer to like components. However, it should be understood that the use of numbers refers to components in a given diagram and is not It is intended to limit the components in the other figures labeled with the same number.

This application provides an efficient and bright source of polarized light. This configuration is compact, efficient and has a particularly low light spread. One conventional technique for increasing the polarized light output of an LED illuminator (i.e., without considering wavelength down conversion) is to use a reflective polarizer to reflect unused polarized light back to the source. The LED source typically randomizes the polarization state and again sends a portion of the light back to the reflective polarizer. A typical conventional recirculating polarizer system increases brightness and output by 10% to 15%. The illumination system described herein provides an improved system that may have 40% to 50% compared to conventional systems.

This application describes a broadband solid state illumination source utilizing a phosphor layer or material that is pumped or energized by light from one or more LEDs. The sources also include reflectors and collimating optics. In some cases, the reflector can be a bi-directional color reflector that reflects at least some of the LED light onto the phosphor layer. Light that exits the LED propagates within the collimation angle of the collimating optics. The light is reflected from the reflector and directed back through the collimating optics to the phosphor layer. Phosphor-converting LEDs are one way to produce wavelengths and bandwidths that are different from the wavelengths and bandwidths that can be effectively generated by the LEDs. Light generation efficiency is one of the important attributes of LED illuminator performance, and techniques that increase efficiency and especially while maintaining reduced light spread are important for many applications.

Both techniques are typically used to perform wavelength down conversion using, for example, a phosphor to produce light having a longer wavelength. In one technique, the input light pumps (i.e., excites) one side of the phosphor and emits the downconverted light from the other side of the phosphor. In another technique, the incident excitation light and the useful emission light are from the same side of the phosphor. In some cases, there are also two modes. A device that operates simultaneously. Typically, where both the excitation and the useful emissions are on the same side of the wavelength converter, the back of the converter can be lined with a mirror. Polarization converters are extremely effective, but they also double the amount of light. Polarized recirculation systems maintain light spread, but generally have low efficiency, especially in the case of LED-based systems.

For the purposes of the description provided herein, both "color light" and "wavelength spectral light" are intended to mean light having a wavelength spectrum that is relevant to a particular color (if visible to the human eye). The more general term "wavelength spectral light" refers to light of visible light and other wavelengths of light, including, for example, infrared light.

Moreover, for the purposes of the description provided herein, the term "aligned with the desired polarization state" is intended to relate to the pass axis of the optical element and the desired polarization state through the optical element (ie, Light alignment such as s polarization, p polarization, right circular polarization, left circular polarization or the like to be polarized. In one embodiment described herein with reference to the figures, an optical element (such as a polarizer) that is aligned with a first polarization state means passing light in a p-polarized state and reflecting or absorbing a second polarization. The orientation of the polarizer of the light of the state (in this case the s-polarized state). It will be appreciated that the polarizer may alternatively be aligned to pass light in the s-polarized state and reflect or absorb light in the p-polarized state, as desired.

In a particular embodiment, the present invention describes a phosphor converted LED having a blue or UV emitting LED, a phosphor that is excited by blue or UV light and produces light having a longer wavelength, an optical collimator, and a bidirectional a color mirror in which the phosphor is in an optically uniform layer that transmits 5% to 50% of the excitation light, And the bidirectional color mirror preferentially reflects the excitation light and transmits the light having a longer wavelength. Light from the LED is reflected by the bidirectional color mirror and focused by the lens assembly onto the front side of the phosphor layer. The phosphor is back lined with a mirror and 5% to 50% of the light from the LED is transmitted through the phosphor to the mirror and reflected back through the phosphor layer. The light system is depolarized by scattering in the phosphor, collimated through the collimating optics, and the portion of the scattered light can be recycled again or transmitted through the reflective polarizer.

In a particular embodiment, an illuminator having an LED that produces light in the range of blue to UV light is substantially collimated by at least one first lens assembly, by being disposed on a surface of the first lens assembly The long pass bi-directional color mirror is reflected and focused by the second lens to illuminate the area of the wavelength converting phosphor. The light emitted by the phosphor is collimated by the first and second lens assemblies, passes through the bidirectional color mirror and passes through the reflective polarizer. The light reflected by the reflective polarizer is focused by the first and second lenses to the illumination region of the phosphor.

In a particular embodiment, an illuminator having an LED that produces light in the range of blue to UV light is substantially collimated by at least one first lens assembly, by a long pass disposed within the first lens assembly The two-way color mirror reflects and is focused by the second lens to illuminate the area of the wavelength converting phosphor. The light emitted by the phosphor is collimated by the first and second lens assemblies, passes through the bidirectional color mirror and passes through the reflective polarizer. The light reflected by the reflective polarizer is focused by the first and second lenses to the illumination region of the phosphor.

Of particular concern is the applicant's surprise finding that the polarization conversion efficiency can increase as the thickness of the phosphor decreases. Although I don't want to be subject to any particular theoretical bundle Binding, but this situation is partly due to the scattering process in the phosphor layer that results in less depolarization and by using a single-pass output, the single-pass output can be made by selecting an optional quarter wave The retarder is placed adjacent to the reflective polarizer. In some cases, the retarder can be placed at any desired location within the optical path between the phosphor and the reflective polarizer; however, adjacent to the reflective polarizer is especially preferred. In some cases, the fast axis of the quarter wave retarder can be rotated such that the fast axis forms an angle with the fast axis of the reflective polarizer, such as in an angle ranging from about 5 degrees to about 40 degrees. Or from about 15 degrees to about 30 degrees, or from about 20 degrees to about 25 degrees, or about 22.5 degrees. This rotation can be used to simulate random depolarization in situations where the phosphor is extremely thin and not sufficiently scattered. In some cases, certain optimizations of the system may include parameters including, for example, phosphor particle size and distribution, phosphor substrate refractive index, phosphor layer thickness, birefringence in the phosphor (eg, phosphor) Addition of glass particles to crystalline phosphors) and non-luminescent scattering particles such as titanium dioxide.

The reflective polarizer can be any known reflective polarizer and can be based on a dielectric multilayer optical film (MOF), such as the Vikuiti ^(TM) Advanced Polarization Film (APF) available from 3M Company. The reflective polarizer can also be based on a circular polarizer such as a cholesteric reflective polarizer, or a MacNeille type polarizer or a wire grid type reflective polarizer. According to an embodiment, the multilayer optical film type polarizer can be a preferred reflective polarizer.

Polymeric multilayer optical film type polarizers can be particularly preferred reflective polarizers, which can include film packaging. Generally, light of higher energy wavelengths, such as blue light, can adversely affect the aging stability of the film, and at least For this reason, the number of interactions of the blue light with the reflective polarizer is preferably minimized. In addition, the interaction of blue light with the film exacerbates the effects of adverse aging. The transmission of blue light across the film is generally less harmful than the reflection of blue light entering from the "blue layer" (i.e., thin layer) side. Moreover, the reflection of blue light entering the film from the "blue light layer" side is generally less harmful than the reflection of blue light entering from the "red light layer" (i.e., thick layer) side. A number of techniques have been described to reduce the number of interactions of actinic light with a reflective polarizer and to reduce the severity of the interaction.

According to one aspect, the illumination system includes a color selective bi-directional color mirror that is positioned to reflect blue light toward the wavelength converting phosphor and to transmit light of other wavelengths to the reflective polarizer. A color selective bi-directional color mirror is positioned within the collimating optics and is used to protect the reflective polarizer from light that can damage the reflective polarizer (ie, such as higher energy blue or ultraviolet (UV) light. Actinic light). The color selective dichroic mirror intercepts the blue light before it is intercepted by the reflective polarizer by blue light (i.e., potentially damaged light). The color selective bi-directional color mirror reflects a major portion of the blue light back to the phosphor for recycling, and also transmits a minor portion through to the reflective polarizer. In one aspect, the main portion reflected by the color selective dichroic mirror may be greater than 51%, 60%, 70%, 75%, 80% of the first color light incident on the color selective bidirectional color mirror, 85% or even more than 90%.

In one aspect, the present invention is directed to further improving the stability of the reflective polarizer by always preventing most of the actinic light from reaching the reflective polarizer in the optical component, such as a polarization recirculating illuminator. Color selective two-way color The mirror reflects a major portion of the actinic light while transmitting a major portion of the light of other wavelengths. In a particular embodiment, a color selective bi-directional color mirror can be placed adjacent to the reflective polarizer. In a particular embodiment, a color selective bidirectional color mirror can be formed directly on the reflective polarizer. In a particular embodiment, a color selective bi-directional color mirror is alternatively formed on an optical element, such as a second hexagonal cylinder, which optical element is then positioned adjacent to the reflective polarizer. In a particular embodiment, the color selective bi-directional color mirror can be a separate film or plate element positioned adjacent to the reflective polarizer. In a particular embodiment, a color selective bi-directional color mirror can be disposed on or in any optical component of the collimating optics separating the phosphor from the reflective polarizer, as described elsewhere. The color selective bidirectional color mirror can be formed by any known process, such as vacuum deposition of an inorganic dielectric stack. In one aspect of the invention, the blue light layer can be eliminated from the reflective polarizer because the major portion of the blue light has been reflected by the color selective bidirectional color mirror before the blue light interacts with the reflective polarizer.

In a particular embodiment, the phosphor can be a semiconductor such as a Group II-VI based system or a phosphor based on nitride, sulfide, selenide, and alumina, as described elsewhere. The phosphor may be a broadband emitter comprising one or more wavelength ranges covering the red, green or blue spectrum, or the phosphor may have a medium bandwidth covering, for example, the green portion of the spectrum, or the phosphor may be Narrowband transmitter. In some cases, the phosphor layer can be optically thin, meaning that the phosphor layer transmits 5% to 50% or more preferably 5% to 30% of the transmitted light.

The present invention describes an LED that illuminates a phosphor at a distal end, wherein the LED The material is coupled to the collimating optics by a material having a relatively low refractive index, and the phosphorescent system is coupled to the collimating optics by a material having a relatively high refractive index. In a particular embodiment, LEDs and phosphors can use common collimating optics; however, separate collimating optics can also be used.

It is generally known that the light spread of a light source is proportional to the square of the refractive index of the encapsulation surrounding the source. Because of the limited optical spread of many optical devices, it is often preferred to encapsulate a light source (e.g., an LED) in a low refractive index material such as air. In some optical devices, LEDs are used to excite wavelength converting materials such as phosphors or semiconductor wavelength converters. Many phosphor and semiconductor wavelength converters are more efficient when immersed in a package having a relatively high refractive index. Also, semiconductor wavelength converters can be expensive or contain hazardous materials, or both expensive and contain hazardous materials. Under such conditions, it may be desirable to immerse the wavelength converter in a medium having a higher refractive index to reduce the desired area. The disclosed apparatus has high optical efficiency in which the LED is in a low refractive index envelope and the phosphor is in a package having a higher refractive index while substantially not increasing the light spread of the system.

In some cases, the LED emits blue light (or UV light) and the reflector reflects the blue LED light onto the phosphor layer. One portion of the blue LED light can be combined with the longer wavelength light emitted by the phosphor to provide a broadband output beam, such as light having a white appearance. In some cases, the LEDs and/or phosphors can be disposed on the substrate, and the LEDs and phosphors are adhered or attached to the substrate in close proximity to one another. In a particular embodiment, the substrate can be a flexible substrate or a rigid substrate, and can include reflective regions on which phosphors are deposited, as described elsewhere.

In this regard, "light emitting diode" or "LED" refers to a diode that emits light (whether visible, ultraviolet or infrared). "Light Emitting Diodes" or "LEDs" include discontinuously enclosed or encapsulated semiconductor devices sold as "LEDs" (known or super-radiated). "LED dies" are LEDs in their most basic form (i.e., in the form of individual components or wafers fabricated by semiconductor processing procedures). Pumped LEDs can emit light in the blue or UV range or both. LEDs can include super-radiation LEDs, lasers including laser diodes, and conventional LEDs, as described elsewhere.

In some cases, the LED can be a short wavelength LED capable of emitting UV photons. In general, the LED can be composed of any suitable material, such as an organic semiconductor or an inorganic semiconductor, including a Group IV element such as Si or Ge; such as InAs, AlAs, GaAs, InP, AlP, GaP, InSb, AlSb, GaSb, GaN , AlN, InN III-V compound and III-V compound alloy (such as AlGaInP and AlGaInN); such as ZnSe, CdSe, BeSe, MgSe, ZnTe, CdTe, BeTe, MgTe, ZnS, CdS, BeS, MgS An alloy of a Group II-VI compound and a Group II-VI compound, or an alloy of any of the compounds listed above.

In some cases, the LED can include one or more p-type and/or n-type semiconductor layers, can include one or more potential wells and/or one or more active layers of a quantum well, a buffer layer, a substrate layer, and a top Plate layer.

In some cases, the LED may include a CdMgZnSe alloy having the compounds ZnSe, CdSe, and MgSe as its three components. In some cases, one or more of Cd, Mg, and Zn (especially Mg) may be zero in the alloy and thus may not be in the alloy. For example, the LCD can be further The steps include a light converting element (LCE) that can be used to convert light from one wavelength to another. In some cases, the LCE may include a Cd0.70Zn0.30Se quantum well capable of emitting red light or a Cd0.33Zn0.67Se quantum well capable of emitting green light. As another example, the LED and/or LCE may comprise an alloy of Cd, Zn, Se, and (as appropriate) Mg, in which case the alloy system may be represented by Cd(Mg)ZnSe. As another example, the LEDs and/or LCEs can include alloys of Cd, Mg, Se, and (as appropriate) Zn. In some cases, the thickness of the quantum well LCE is in the range of from about 1 nm to about 100 nm or from about 2 nm to about 35 nm.

In some cases, the semiconductor LED or LCE can be n-doped or p-doped, wherein doping can be achieved by any suitable method and by including any suitable dopant. In some cases, the LEDs and LCEs are from the same semiconductor family. In some cases, LEDs and LCEs come from two different semiconductor families. For example, in some cases, the LEDs are III-V semiconductor devices and the LCEs are II-VI semiconductor devices. In some cases, the LED includes an AlGaInN semiconductor alloy and the LCE includes a Cd(Mg)ZnSe semiconductor alloy. The LCE can generally be a phosphor, such as a phosphor particle in an organic binder, in an inorganic binder, or can be a semiconductor such as a ZnSe or ZnS compound.

The LCE can be disposed on or attached to the corresponding electroluminescent element by any suitable method, such as by an adhesive such as a hot melt adhesive, soldering, pressure, heat, or any combination of such methods. Light-emitting element. Examples of suitable hot melt adhesives include semicrystalline polyolefins, thermoplastic polyesters, and acrylic resins.

In a particular embodiment, the LED die can be formed from one or more Group III elements and a combination of one or more Group V elements (Group III-V semiconductors). Examples of suitable III-V semiconductor materials include nitrides such as gallium nitride and phosphides such as gallium indium phosphide. Other types of III-V materials as well as inorganic materials from other families of the periodic table can also be used. The component or wafer may include electrical contacts adapted to apply electrical power to supply energy to the device. Examples include wire bonding, tape automated bonding (TAB) or flip chip bonding. The individual layers and other functional components of the component or wafer are typically formed on a wafer scale, and the completed wafer can then be divided into individual components to yield a plurality of LED dies. LED dies can be configured for surface bonding, on-board wafers, or other known adhesive configurations. Some packaged LEDs are fabricated by forming a polymer encapsulant on the LED dies and associated reflective cups. For the purposes of this application, "LED" should also be considered to include organic light-emitting diodes commonly referred to as OLEDs.

The present invention allows for light spread matching of LED sources that do not require encapsulation to achieve good efficiency. In some cases, the LED source can be encapsulated in a material having a refractive index between about 1.0 and about 1.2 or about 1.0 (ie, air). In some cases, the LED source may have a limit on the allowable drive current density. In some cases, the phosphor can operate at high power densities, and in order to achieve higher efficiency of the pumping system, it is generally preferred to use an encapsulant to optically couple the phosphor to the primary optic.

In a particular embodiment, the area of the LED source is significantly larger than the area of the phosphor, and focusing optics can be used to increase the angular extent of illumination of the phosphor, which can be coupled to the focusing optics by a particular encapsulant , the The refractive index of the encapsulant is higher than the refractive index of the material surrounding the LED. In some cases, the encapsulant can have a refractive index between about 1.2 and about 1.6 or between about 1.4 and about 1.5 or a refractive index of, for example, about 1.41.

In some cases, the etendue of the encapsulated phosphor can be matched to the unencapsulated LED, for example, by using a tapered rod to concentrate light from the LED source onto the phosphor. The tapered rod can be optically coupled to the collimating optics or can be separated from the collimating optics by an air gap. The phosphor can be optically coupled to the narrower substrate of the tapered rod by an encapsulating material such as polydimethyl oxyhydroxide. In some cases, a compound parabolic concentrator (CPC) can be used instead of a tapered rod. The CPC or tapered rod can be made of glass or plastic. The phosphor may be bonded to the tapered rod or CPC by a material such as polydimethyl oxyhydroxide having a refractive index of about 1.2 or higher, preferably 1.4 or higher.

1A shows a cross-sectional schematic view of an illumination system 100 in accordance with an aspect of the present invention. In FIG. 1A, illumination system 100 includes a collection optics 105 that includes a first lens element 110 and a second lens element 120. The collection optics 105 includes a light input surface 114 and an optical axis 107 that is perpendicular to the light input surface 114. The first light source 140 is disposed on the light exit surface 104 that faces the light input surface 114. In some cases, the first source 140 can be a non-polarized source. The light conversion region 170 is disposed on the light exit surface 104 in close proximity to the first light source 140. In some cases, one of the light conversion region 170 and the first light source 140 is disposed on the optical axis 107 and in close proximity to each other. In some cases, each of the light conversion region 170 and the first light source 140 is displaced from the optical axis 107 and in close proximity to each other. However, the first light source 140 and the light conversion region 170 are generally disposed in close proximity to the optical axis 107 such that the emission from the first light source 140 can be maintained And the collimation angle of the light guided to the light conversion region 170. In a particular embodiment, FIG. 1A shows a configuration of first light source 140 slightly above optical axis 107 and light conversion region 170 disposed on optical axis 107. In some cases, a second source (not shown) can be disposed at a location removed from the light exit surface 104 to direct the second light directly toward the light conversion region 170.

Any suitable substrate can be used for the light exiting surface 104 and can include a conductive layer or trace to carry electrical power to the LED. Preferably, the substrate also has a relatively high thermal conductivity and a relatively low thermal resistance to effectively carry heat away from the LED and/or phosphor layer in order to maintain a lower operating temperature of the LED and/or phosphor layer. To facilitate such lower operating temperatures, the substrate may comprise a suitable heat sink or be thermally coupled to a suitable heat sink, for example, a relatively thick copper layer, an aluminum layer or other suitable metal layer or other thermally conductive material (not shown) Show) layer. In some cases, the substrate can be or comprise a highly reflective surface such as a metal mirror, a metal mirror with a dielectric coating to enhance reflectivity, or a diffuse reflective surface such as a microporous polyester or titanium dioxide filled polymer, or such as 3M ^TM Vikuiti ^TM reflector enhanced specular reflector (ESR) multilayer optical film of the film. The substrate can also be or comprise any of the substrates discussed elsewhere herein.

The substrate can include a dielectric layer. Suitable dielectric layers include polyesters, polycarbonates, liquid crystal polymers, and polyimines. Suitable polyimides include those available from DuPont under the trade name KAPTON, from Kaneka Texas corporation under the trade name APICAL, from SKC Kolon PI Inc. under the trade name SKC Kolon PI, and from Ube Industries under the trade names UPILEX and UPISEL. They are polyimine. Polyimine available under the trade names UPILEX S, UPILEX SN and UPISEL VT Available from Ube Industries, Japan) is particularly advantageous in many applications. These polyimines are made from monomers such as biphenyl phthalic anhydride (BPDA) and p-phenylenediamine (PDA).

Additional design details of an exemplary flexible substrate suitable for use in the disclosed embodiments can be found in the commonly-owned U.S. Patent Application, entitled: "Flexible LED Device and Method of Making", filed on November 3, 2010. US Application No. 61/409,796 (Attorney Docket No. 66938US003); US Application No. 61/409,801, entitled "Flexible LED Device for Thermal Management and Method of Making", filed on November 3, 2010 (Attorney Docket No.) 67018US002); US Application 61/428034 (Attorney Docket No. 67006US002) entitled "Remote Phosphor LED Constructions", filed on December 29, 2010; and "LED Color Combiner", filed on December 29, 2010 US Application 61/428038 (Attorney Docket No. 67010US002).

In a particular embodiment, illumination system 100 further includes a wavelength selective reflector 132 disposed within optical collection optics 105 along optical axis 107. The wavelength selective reflector is configured to reflect light emitted from the first source 140 to the light conversion region 170, and thus may include a lens shape. The wavelength selective reflector 132 can be a bidirectional color reflector that is capable of reflecting the first color light 141a and transmitting all other color lights.

In a particular embodiment, the collection optics 105 can be a light collimating optic 105 that collimates light emitted from the first source 140. The light collimating optics 105 can include a single lens optical collimator (not shown), dual lens light A collimator (shown in the figures), a diffractive optical element (not shown), or a combination thereof. The dual lens optical collimator has a first lens element 110 that includes a first lens portion 116 including a light input surface 114, a second lens portion 111, and a first surface disposed opposite the light input surface 114 A third lens portion 113 of a convex surface 112. The wavelength selective reflector 132 is disposed between the first lens portion 116 and the second lens portion 111. The wavelength selective reflector 132 can be disposed on the first lens portion 116, disposed on the second lens portion 111, disposed on both the first lens portion 116 and the second lens portion 111, or the wavelength selective reflector 132 can be It is a separate film positioned between the first lens portion 116 and the second lens portion 111. The second lens element 120 includes a second surface 122 facing the first convex surface 112 and a third convex surface 124 opposite the second surface 122. The second surface 122 can be selected from a convex surface, a flat surface, and a concave surface.

The path of the first color light 141a from the first source 140 through the illumination system 100 can be tracked. The first color light 141a includes a first center ray 142a traveling in the first light propagation direction and a ray cone within the first input light collimation angle θ1i, the boundary of the ray cone being represented by the first boundary ray 144a, 146a. The first central ray 142a and the first boundary ray 144a and the second boundary ray 146a are emitted from the first light source 140 in a direction substantially parallel to the optical axis 107 and within the first input light collimation angle θ1i to the light input surface 114. in. Each of the first boundary ray 144a, 146a and the first central ray 142a is reflected from the wavelength selective reflector 132 such that each of the first boundary reflected ray 144b, 146b and the first central reflected ray 142b is oriented The light conversion region 170 reflects.

In a particular embodiment as shown in FIG. 1A, reflected light 142b, 144b, 146b is concentrated to a light conversion region 170 where the reflected light 142b, 144b, 146b is wavelength converted and used as a first conversion. The light 141c is re-emitted into the light collimating optics 105. The light conversion region 170 downconverts a major portion of the reflected light 142b, 144b, 146b and redirects both the first converted light 141c and the remaining portions of the incident reflected light 142b, 144b, 146b back to the light collimating optics 105, as described elsewhere.

First boundary converted ray 144c, 146c having a first transition collimation angle θ1o and first center converted ray 142c pass through wavelength selective reflector 132, travel through optical collimation optics 105, through optional retarder 136 and Intercepted by reflective polarizer 134. The first converted light 141c is split by the reflective polarizer 134 into a converted converted light 142d, 144d, 146d (eg, p-polarized converted light) having a first polarization state and a reflection having a second polarization state. Light 142e, 144e, 146e (eg, s polarization converted light). The s polarization converted light 142e, 144e, 146e travels back through the optional retarder 136, the light collimating optics 105, the wavelength selective reflector 132 and is again focused on the light converting region 170 at the light converting region 170 The s polarization converted ray 142e, 144e, 146e is reflected back along the same path as the first converted ray 141c (and possibly depolarized by scattering in the phosphor layer). In a particular embodiment, the optional retarder can assist in the depolarization of the converted light back to the phosphor by partial rotation of the polarization state, as described elsewhere.

In a particular embodiment, the input collimation angle θ1i can be the same as the conversion collimation angle θ1o, and the exit optics associated with the first source 140 (not shown) The input collimation angle can be limited to an angle in the range of between about 10 degrees and about 80 degrees, or between about 10 degrees and about 70 degrees, or between about 10 degrees and about 60 degrees. Or between about 10 degrees and about 50 degrees, or between about 10 degrees and about 40 degrees, or between about 10 degrees and about 30 degrees, or less. In some cases, the light collimating optics 105 and the wavelength selective reflector 132 can be fabricated such that the switching collimation angles θ1o can be the same and substantially equal to the input collimation angle θ1i. In a particular embodiment, each of the input collimation angles is between about 60 degrees and about 70 degrees, and the transition collimation angle is also between about 60 degrees and about 70 degrees.

FIG. 1B shows a cross-sectional schematic view of an illumination system 101 in accordance with an aspect of the present invention. Each of the elements 104-170 shown in FIG. 1B corresponds to the same numbered elements shown in FIG. 1A that have been previously described.

In a particular embodiment, the collection optics 105 can be a light collimating optic 105 that collimates light emitted from the first source 140. Light collimating optics 105 can include a single lens optical collimator (not shown), a dual lens optical collimator (shown in the figures), a diffractive optical element (not shown), or a combination thereof. The dual lens optical collimator has a first lens element 110 that includes a first convex surface 112 disposed opposite the light input surface 114. The wavelength selective reflector 132 is disposed on the first convex surface 112. The second lens element 120 includes a second surface 122 facing the first convex surface 112 and a third convex surface 124 opposite the second surface 122. The second surface 122 can be selected from a convex surface, a flat surface, and a concave surface.

The path of the first color light 141a from the first source 140 through the illumination system 100 can be tracked. The first color light 141a is included in the first light propagation direction The traveling first central ray 142a and the ray cone within the first input light collimation angle θ1i, the boundary of the ray cone is represented by the first boundary ray 144a, 146a. The first central ray 142a and the first boundary ray 144a and the second boundary ray 146a are emitted from the first light source 140 in a direction substantially parallel to the optical axis 107 and within the first input light collimation angle θ1i to the light input surface 114. in. Each of the first boundary ray 144a, 146a and the first central ray 142a is reflected from the wavelength selective reflector 132 such that each of the first boundary reflected ray 144b, 146b and the first central reflected ray 142b is oriented The light conversion region 170 reflects.

In a particular embodiment as shown in FIG. 1B, the reflected light 142b, 144b, 146b converges to the light conversion region 170 where the reflected light 142b, 144b, 146b is wavelength converted and used as the first conversion The light 141c is re-emitted into the light collimating optics 105. The light conversion region 170 downconverts a major portion of the reflected light 142b, 144b, 146b and redirects both the first converted light 141c and the remaining portions of the incident reflected light 142b, 144b, 146b back to the light collimating optics 105. Medium, as described elsewhere.

First boundary converted ray 144c, 146c having a first transition collimation angle θ1o and first center converted ray 142c pass through wavelength selective reflector 132, travel through optical collimation optics 105, through optional retarder 136 and Intercepted by reflective polarizer 134. The first converted light 141c is split by the reflective polarizer 134 into a converted converted light 142d, 144d, 146d (eg, p-polarized converted light) having a first polarization state and a reflection having a second polarization state. Light 142e, 144e, 146e (eg, s polarization converted light). s The polarization converted light 142e, 144e, 146e travels back through the optional retarder 136, the light collimating optics 105, the wavelength selective reflector 132, and again onto the light converting region 170, at the light converting region 170, The s polarization converted rays 142e, 144e, 146e are reflected back along the same path as the first converted ray 141c (and possibly depolarized by scattering in the phosphor layer). In a particular embodiment, the optional retarder can assist in the depolarization of the converted light back to the phosphor by partial rotation of the polarization state, as described elsewhere.

1C shows a cross-sectional schematic view of an illumination system 102 in accordance with an aspect of the present invention. Each of the elements 104-170 shown in Figure 1C corresponds to the same numbered elements shown in Figure 1A that have been previously described.

In a particular embodiment, the collection optics 105 can be a light collimating optic 105 that collimates light emitted from the first source 140. Light collimating optics 105 can include a single lens optical collimator (not shown), a dual lens optical collimator (shown in the figures), a diffractive optical element (not shown), or a combination thereof. The dual lens optical collimator has a first lens element 110 that includes a first convex surface 112 disposed opposite the light input surface 114. The second lens element 120 has a fourth lens portion 121 including a second surface 122 facing the first convex surface 112, a fifth lens portion 125 disposed adjacent to the fourth lens portion 121, and disposed adjacent to the fifth lens portion And a sixth lens portion 123 having a third convex surface 124 opposite the second surface 122. The wavelength selective reflector 132 is disposed between the fifth lens portion 125 and the sixth lens portion 123. The wavelength selective reflector 132 may be disposed on the fifth lens portion 125, disposed on the sixth lens portion 123, disposed on both the fifth lens portion 125 and the sixth lens portion 123, or wavelength The selective reflector 132 can be a separate film positioned between the fifth lens portion 125 and the sixth lens portion 123. The second surface 122 can be selected from a convex surface, a flat surface, and a concave surface.

The path of the first color light 141a from the first source 140 through the illumination system 100 can be tracked. The first color light 141a includes a first center ray 142a traveling in the first light propagation direction and a ray cone within the first input light collimation angle θ1i, the boundary of the ray cone being represented by the first boundary ray 144a, 146a. The first central ray 142a and the first boundary ray 144a and the second boundary ray 146a are emitted from the first light source 140 and within the first input light collimation angle θ1i in a direction substantially parallel to the optical axis 107 to the light input surface 114. in. Each of the first boundary ray 144a, 146a and the first central ray 142a is reflected from the wavelength selective reflector 132 such that each of the first boundary reflected ray 144b, 146b and the first central reflected ray 142b is oriented The light conversion region 170 reflects.

In a particular embodiment as shown in FIG. 1C, the reflected light rays 142b, 144b, 146b converge to the light conversion region 170 where the reflected light rays 142b, 144b, 146b are wavelength converted and used as the first conversion The light 141c is re-emitted into the light collimating optics 105. The light conversion region 170 downconverts a major portion of the reflected light 142b, 144b, 146b and redirects both the first converted light 141c and the remaining portions of the incident reflected light 142b, 144b, 146b back to the light collimating optics 105. Medium, as described elsewhere.

The first converted light 141c includes first boundary converted rays 144c, 146c having a first converted collimation angle θ1o and a first central converted ray 142c. the first The central conversion ray 142c travels generally back through the same path as the central reflected ray 142b (but in the opposite direction of propagation) to pass through the light collimating optics 105. In a particular embodiment, the light conversion region 170 can be configured such that the first boundary conversion ray 144c, 146c also travels substantially along the same path as the first boundary reflected light 144b, 146b (but in the opposite propagation direction). It passes back through the light collimating optics 105.

First boundary converted rays 144c, 146c having a first transition collimation angle θ1o and first central converted ray 142c travel through light collimating optics 105, through wavelength selective reflector 132, through optional retarder 136 and Intercepted by reflective polarizer 134. The first converted light 141c is split by the reflective polarizer 134 into a converted converted light 142d, 144d, 146d (eg, p-polarized converted light) having a first polarization state and a reflection having a second polarization state. Light 142e, 144e, 146e (eg, s polarization converted light). The s polarization converted light 142e, 144e, 146e travels back through the optional retarder 136, the light collimating optics 105, the wavelength selective reflector 132 and is again focused on the light converting region 170 at the light converting region 170 The s polarization converted ray 142e, 144e, 146e is reflected back along the same path as the first converted ray 141c (and possibly depolarized by scattering in the phosphor layer). In a particular embodiment, the optional retarder can assist in the depolarization of the converted light back to the phosphor by partial rotation of the polarization state, as described elsewhere.

1D shows a cross-sectional schematic view of an illumination system 103 in accordance with an aspect of the present invention. Each of the elements 104-170 shown in FIG. 1D corresponds to the same numbered elements shown in FIG. 1A that have been previously described.

In a particular embodiment, the collection optics 105 can be used to A light collimating light collimating optic 105 emitted by a light source 140. Light collimating optics 105 can include a single lens optical collimator (not shown), a dual lens optical collimator (shown in the figures), a diffractive optical element (not shown), or a combination thereof. The dual lens optical collimator has a first lens element 110 that includes a first convex surface 112 disposed opposite the light input surface 114. The second lens element 120 includes a second surface 122 facing the first convex surface 112 and a third convex surface 124 opposite the second surface 122. The wavelength selective reflector 132 is disposed on the third convex surface 124. The second surface 122 can be selected from a convex surface, a flat surface, and a concave surface.

The path of the first color light 141a from the first source 140 through the illumination system 100 can be tracked. The first color light 141a includes a first center ray 142a traveling in the first light propagation direction and a ray cone within the first input light collimation angle θ1i, the boundary of the ray cone being represented by the first boundary ray 144a, 146a. The first central ray 142a exits the first source 140 and is directed into the light input surface 114 in a direction generally parallel to the optical axis 107 and within the first input light collimation angle θ1i. The first central ray 142a passes through the first lens element 110, the second lens element 120, and is reflected from the wavelength selective reflector 132 such that the first central reflected ray 142b coincides with the optical axis 107, as shown in FIG. Each of the first boundary ray 144a, 146a exits in a direction substantially perpendicular to the optical axis 107 at a first input light collimation angle θ1i, into the light input surface 114, through the first lens element 110, the second lens Element 120 is reflected from wavelength selective reflector 132 such that first boundary reflected rays 144b, 146b are substantially parallel to optical axis 107, respectively, before re-entering light collimating optics 105, as shown. As can be seen from Figure 1D, the light collimating optics The member 105 can be used to collimate the first color light 141a that is transmitted from the first source 140 to the wavelength selective reflector 132.

Each of the first central ray 142a and the first boundary ray 144a, 146a is reflected from the wavelength selective reflector 132 and is collimated and substantially parallel to the optical axis 107 and, in some cases, concentrated on the optical axis 107. The central reflected ray 142b and the first boundary reflected ray 144b and the second boundary reflected ray 146b (e.g., as shown in FIG. 1) travel back through the light collimating optics 105. In a particular embodiment as shown in FIG. 1D, the reflected light rays 142b, 144b, 146b converge to the light conversion region 170 where the reflected light rays 142b, 144b, 146b are wavelength converted and used as the first conversion The light 141c is re-emitted into the light collimating optics 105. The light conversion region 170 downconverts a major portion of the reflected light 142b, 144b, 146b and redirects both the first converted light 141c and the remaining portions of the incident reflected light 142b, 144b, 146b back to the light collimating optics 105. Medium, as described elsewhere.

The first converted light 141c includes first boundary converted rays 144c, 146c having a first converted collimation angle θ1o and a first central converted ray 142c. The first central converted ray 142c travels generally back through the same path as the central reflected ray 142b (but in the opposite direction of propagation) to pass through the light collimating optics 105. In a particular embodiment, the light conversion region 170 can be configured such that the first boundary conversion ray 144c, 146c also travels substantially along the same path as the first boundary reflected light 144b, 146b (but in the opposite propagation direction). It passes back through the light collimating optics 105.

a first boundary conversion ray 144c having a first conversion collimation angle θ1o, The 146c and first central converted ray 142c travel through the light collimating optics 105, through the wavelength selective reflector 132, through the optional retarder 136, and are intercepted by the reflective polarizer 134. The first converted light 141c is split by the reflective polarizer 134 into a converted converted light 142d, 144d, 146d (eg, p-polarized converted light) having a first polarization state and a reflection having a second polarization state. Light 142e, 144e, 146e (eg, s polarization converted light). The s polarization converted light 142e, 144e, 146e travels back through the optional retarder 136, the light collimating optics 105, the wavelength selective reflector 132 and is again focused on the light converting region 170 at the light converting region 170 The s polarization converted ray 142e, 144e, 146e is reflected back along the same path as the first converted ray 141c (and possibly depolarized by scattering in the phosphor layer). In a particular embodiment, the optional retarder can assist in the depolarization of the converted light back to the phosphor by partial rotation of the polarization state, as described elsewhere.

Although the foregoing description has been directed to illuminators that generate polarized light, it should be understood that the illuminators can also be used to effectively generate non-polarized light by eliminating reflective polarizers 134 (and optional retarders 136). This elimination reduces polarization recycling and therefore also reduces light conversion efficiency. Non-polarized light can be converted to polarized light by other techniques such as those described elsewhere and as known to those skilled in the art.

2A shows a schematic diagram of a configuration near the light conversion region 170 of the illumination systems 100-103 shown in FIGS. 1A through 1D, in accordance with an aspect of the present invention. Each of the elements 104-170 shown in FIG. 2A corresponds to the same numbered elements shown in FIGS. 1A through 1D that have been previously described. In FIG. 2A, light conversion region 170 includes phosphor 150 disposed on reflective region 106 of light exit surface 104 and surrounded by encapsulant 155. The refractive index of the encapsulant 155 is greater than The refractive index of the material surrounding the first source 140 as described elsewhere. The encapsulant 155 can be any of the encapsulating materials previously described, such as polydimethylox. In some cases, the encapsulant 155 can completely fill the gap between the light exit surface 104 and the light input surface 114.

In some cases, the encapsulant 155 can alternatively be fabricated as a lens that includes a curved surface 156 (as shown in FIG. 2A) to focus the reflected light 142b, 144b, 146b that is incident on the light input surface 114 onto the phosphor 150. . After being intercepted by the phosphor 150, a substantial portion of the reflected rays 142b, 144b, 146b are wavelength-converted to become converted rays 142c, 144c, 146c, and are emitted as converted rays 142c, 144c having a conversion collimation angle θ1o, 146c re-enters the lighting system 100. In some cases, the conversion collimation angle θ2o may be the same as the input collimation angle θ1i.

2B shows a schematic diagram of the configuration of the vicinity of the light conversion region 170 of the illumination systems 100-103 shown in FIGS. 1A through 1D in accordance with an aspect of the present invention. Each of the elements 104-170 shown in FIG. 2B corresponds to the same numbered elements shown in FIGS. 1A through 1D that have been previously described. In FIG. 2B, light conversion region 170 includes phosphor 150 disposed on reflective region 106 of light exit surface 104 and surrounded by encapsulant 155. The index of refraction of the encapsulant 155 is greater than the refractive index of the material surrounding the first source 140 as described elsewhere. The encapsulant 155 can be any of the encapsulating materials previously described, such as polydimethylox. In some cases, the encapsulant 155 can completely fill the gap between the light exit surface 104 and the light input surface 114.

In some cases, the encapsulant 155 can be fabricated as a tapered rod 157 (as shown in Figure 2B) to direct the reflected light 142b from the light input surface 114, 144b, 146b are focused onto phosphor 150. The tapered rod 157 can be any of the tapered rods described elsewhere, and can have a reflective surface or a polished surface to achieve TIR from the surfaces. The tapered rod 157 is configured to transport and further concentrate the output light 141c. After being intercepted by the phosphor 150, a substantial portion of the reflected rays 142b, 144b, 146b are wavelength-converted to become converted rays 142c, 144c, 146c, and are emitted as converted rays 142c, 144c having a conversion collimation angle θ1o, Re-enter the lighting system 100 at 146c. In some cases, the conversion collimation angle θ2o may be the same as the input collimation angle θ1i.

2C shows a schematic diagram of a configuration near the light conversion region 170 of the illumination systems 100-103 shown in FIGS. 1A through 1D in accordance with an aspect of the present invention. Each of the elements 104-170 shown in Figure 2C corresponds to the same numbered elements shown in Figures 1A through 1D that have been previously described. In FIG. 2C, the light conversion region 170 includes a phosphor 150 disposed on the reflective region 106 of the light exit surface 104 and surrounded by the encapsulant 155. The index of refraction of the encapsulant 155 is greater than the refractive index of the material surrounding the first source 140 as described elsewhere. The encapsulant 155 can be any of the encapsulating materials previously described, such as polydimethylox. In some cases, the encapsulant 155 can completely fill the gap between the light exit surface 104 and the light input surface 114.

In some cases, the encapsulant 155 can be fabricated as a CPC 158 (as shown in FIG. 2C) to focus the reflected light 142b, 144b, 146b that is incident on the light input surface 114 onto the phosphor 150. The CPC 158 can be any of the CPCs described elsewhere, and can have reflective or polished surfaces to achieve TIR from such surfaces. CPC 158 is configured to deliver and further aggregate output light 141c. After being intercepted by the phosphor 150, a substantial portion of the reflected rays 142b, 144b, 146b are wavelength-converted to become converted rays 142c, 144c, 146c, and are emitted as converted rays 142c, 144c having a conversion collimation angle θ1o, Re-enter the lighting system 100 at 146c. In some cases, the conversion collimation angle θ2o may be the same as the input collimation angle θ1i.

Phosphor 150 can be any of the phosphors described elsewhere, and in some cases can include more than one type of phosphor such that the downconverted light includes more than one wavelength of light. In some conditions (not shown), the downconverted light from the first phosphor can be used to excite the second phosphor to further downconvert the light to different wavelengths of light. In some cases (also not shown), a portion of the downconverted light from the first phosphor can be similar to the first color light 141a as described with reference to any of Figures 1A through 1D. Reflecting from the bi-directional color mirror and exciting the second phosphor to further downconvert the light into different wavelengths of light.

Figure 3 shows a schematic diagram of an image projector 1 in accordance with one aspect of the present invention. The image projector 1 includes a illuminator module 10 that is capable of emitting a partially collimated polarized light output 24 to an optional homogenizing polarization converter module 30, in an optional homogenizing polarization converter module 30. The partially collimated polarized light output 24 is converted into uniformly polarized light 45 that is directed away from the optional uniformized polarization converter module 30 and into the image generator module 50. The image generator module 50 outputs image light 65, which enters the projection module 70. In the projection module 70, the image light 65 becomes the projected image light 80.

In one aspect, illuminator module 10 includes an input source that is input via light collimating optics 105 in illumination system 100, as described elsewhere. Photo The illumination system 100 produces a light output that is directed away from the illuminator module 10 as a partially collimated polarized light output 24, as described elsewhere.

The partially collimated polarized light output 24 can be a multi-color, combined polarized light that contains light of more than one wavelength spectrum. For the purposes of the description provided herein, both "color light" and "wavelength spectral light" are intended to mean light having a wavelength spectrum that is relevant to a particular color (if visible to the human eye). The more general term "wavelength spectral light" refers to light of visible light and other wavelengths of light, including, for example, infrared light.

According to one aspect, each input source comprises one or more light emitting diodes (LEDs). Various light sources can be used, such as lasers, laser diodes, organic LEDs (OLEDs), and non-solid state light sources (such as ultra high voltage (UHP) halogen or xenon lamps with appropriate concentrators or reflectors). Light sources, optical collimators, lenses, and optical integrators that can be used in the present invention are further described in, for example, the published U.S. Patent Application Serial No. US 2008/0285129, the disclosure of which is incorporated herein in its entirety. .

In one aspect, the optional uniformization polarization converter module 30 includes a polarization converter 40 that is capable of converting a partially collimated light output 24 into uniformly polarized light 45. The optional uniformization polarization converter module 30 can further include a single array of lenses 42, such as the optional single-body FEA of the lens described elsewhere, which can be homogenized as uniformly polarized light 45 and can be selectively homogenized. A portion of the polarized converter module 30 collimates the polarized light output 24 and improves the uniformity of the polarized light. A representative configuration of an optional FEA associated with the optional homogenizing polarization converter module 30 is described, for example, in the following patent: "FLY EYE INTEGRATOR POLARIZATION CONVERTER" in the same application. U.S. Patent No. 61/346,183 (Attorney Docket No. 66247US002, filed on May 19, 2010), U.S. Patent No. 61/346,190, entitled "POLARIZED PROJECTION ILLUMINATOR" (Attorney Docket No. 66249US002, May 2010) Application on the 19th, and U.S. Patent No. 61/346,193, entitled "COMPACT ILLUMINATOR" (Attorney Docket No. 66360US002, filed on May 19, 2010). In some cases (not shown), the optional uniformized polarization converter module 30 can be eliminated, in whole or in part, because the output of the illuminator module 10 can include an image that can be adapted for input to the images described below. A portion of the collimated polarized light output 24 in the generator module 50.

In one aspect, image generator module 50 includes a polarizing beam splitter (PBS) 56, representative imaging optics 52, 54 and a spatial light modulator 58 that cooperate to convert uniformly polarized light 45 Image light 65. Suitable spatial light modulators (i.e., image generators) have been previously described, for example, in U.S. Patent Nos. 7,362,507 (Duncan et al.), 7,529,029 (Duncan et al.), U.S. Publication No. 2008-0285129-A1 (Magarill et al.), and PCT Publication No. WO2007/016015 (Duncan et al.). In a particular embodiment, uniformly polarized light 45 is divergent light from each lens of the optional FEA. After passing through imaging optics 52, 54 and PBS 56, uniformly polarized light 45 becomes imaging light 60 that uniformly illuminates the spatial light modulator. In a particular embodiment, each of the diverging ray bundles from each of the lenses in the optional FEA illuminates a major portion of the spatial light modulator 58 such that the individual scatter beams collide with each other.

In one aspect, projection module 70 includes representative projection optics 72, 74, 76 that can be used to project image light 65 as projected light 80. Suitable projection optics 72, 74, 76 have been previously described and are well known to those skilled in the art.

The following is a list of embodiments of the invention.

Item 1 is an illumination system comprising: a light emitting diode (LED) disposed on a substrate and configured to emit a first light beam in a first propagation direction such that the first light beam passes through a Collimating optics; a wavelength selective reflector in the collimating optic, the wavelength selective reflector for reflecting the first beam back through the collimating optics; and a phosphor, Positioned in close proximity to the LED, the phosphor is capable of downconverting a major portion of the first beam to become a second beam, the second beam propagating back in a second propagation direction to pass through the collimating optics The device passes through the wavelength selective reflector.

Item 2 is the illumination system of item 1, wherein the collimating optics comprises a first lens element adjacent to the substrate and a second lens element adjacent to the first lens element and opposite the substrate, the wavelength selective The reflector is disposed on an outer surface of the first lens element or the second lens element or embedded in the first lens element or the second lens element.

Item 3 is the illumination system of item 1 or item 2, wherein the wavelength selective reflector comprises a curved surface capable of focusing the first beam onto the phosphor.

Item 4 is the illumination system of item 1 to item 3, further comprising a reflective polarization disposed adjacent to the collimating optics and opposite the substrate The reflective polarizer is configured to reflect the second beam of a second polarization direction back through the collimating optics to focus on the phosphor and transmit a first polarization direction The second beam.

Item 5 is the illumination system of item 1 to item 4, wherein the collimating optics comprises an optical axis, and at least one of the LED or the phosphor is disposed on the optical axis.

Item 6 is the illumination system of item 1 to item 5, wherein the phosphor comprises an encapsulated phosphor.

Item 7 is the illumination system of item 6, wherein the encapsulated phosphor comprises an encapsulant having a refractive index between about 1.2 and about 1.6.

Item 8 is the illumination system of item 6 or item 7, wherein the encapsulated phosphor comprises an encapsulant having a refractive index between about 1.4 and about 1.5.

Item 9 is the illumination system of item 1 to 8, further comprising a low refractive index material between the LED and the collimating optic, the low refractive index material having a refraction between about 1.0 and about 1.2 rate.

Item 10 is the illumination system of item 9, wherein the low refractive index material is air.

Item 11 is the illumination system of item 1 to item 10, wherein the first light beam comprises a first light ray propagating within a first collimation angle of the first propagation direction.

Item 12 is the illumination system of item 1 to item 11, wherein the second light beam comprises a second light ray propagating within a second collimation angle of one of the second propagation directions opposite the first propagation direction.

Item 13 is the lighting system of items 6 to 12, wherein the encapsulated phosphorus The light body comprises a polydimethyl sulfonium encapsulation.

Item 14 is the illumination system of item 1 to item 13, further comprising a second LED disposed to directly emit a third beam toward the phosphor.

Item 15 is the illumination system of item 1 to item 14, wherein the phosphorescent system is disposed on a reflective substrate.

Item 16 is the illumination system of item 1 to item 15, further comprising a focusing optic disposed between the phosphor and the collimating optic, the focusing optic capable of focusing the first beam.

Item 17 is the illumination system of item 16, wherein the focusing optical element comprises a tapered glass rod or a compound parabolic concentrator (CPC).

Item 18 is the illumination system of item 4 to item 17, further comprising a retarder disposed between the phosphor and the reflective polarizer.

Item 19 is the illumination system of item 18, wherein the retarder is a quarter wave retarder having a fast axis oriented at an angle of 22.5 degrees relative to a fast axis of the reflective polarizer.

Item 20 is the lighting system of item 4 to item 19, wherein the reflective polarizer comprises a cholesteric reflective polarizer, a MacNeille type reflective polarizer, a wire grid reflective polarizer or a multilayer optical film (MOF) ) type reflective polarizer.

Item 21 is the illumination system of item 1 to item 20, wherein the wavelength selective reflector comprises a blue light reflector or an ultraviolet light reflector.

Item 22 is an image projector comprising: an illumination system comprising: a light emitting diode (LED) disposed on a substrate and configured to emit a first light beam in a first propagation direction thereby Passing the first beam through a collimating optics; a wavelength selective reflector in the collimating optic, the wavelength selective reflector for reflecting the first beam back through the collimating optics; and a phosphor, Arranging it adjacent to the LED, the phosphor capable of downconverting a major portion of the first beam to become a second beam, the second beam propagating back in a second propagation direction to pass through the collimation An optical device passing through the wavelength selective reflector; a polarization converter capable of converting the second beam into a third beam having a first polarization direction; an imager disposed to intercept the The second beam of the first polarization direction; and projection optics.

All numbers expressing feature sizes, quantities and physical properties used in the specification and claims are to be understood as being modified by the term "about" unless otherwise indicated. Accordingly, unless otherwise indicated, the numerical parameters set forth in the foregoing description and the appended claims are intended to be <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> <RTIgt; </ RTI> </ RTI> dependent on the desired properties sought to be obtained by those skilled in the art using the teachings disclosed herein.

All of the references and publications cited herein are expressly incorporated herein by reference in their entirety in their entirety in their entirety, unless the same reference While a particular embodiment has been illustrated and described herein, it will be understood by those skilled in the art . This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that the invention be limited only

1‧‧‧Image projector

10‧‧‧ illuminator module

24‧‧‧Partial collimated light output

30‧‧‧Optional Uniform Polarization Converter Module

40‧‧‧Polarization converter

42‧‧‧Lens array of lenses

45‧‧‧Uniformly polarized light

50‧‧‧Image Generator Module

52‧‧‧ imaging optics

54‧‧‧ imaging optics

56‧‧‧Polarized Beam Splitter (PBS)

58‧‧‧Space light modulator

60‧‧‧ imaging light

65‧‧‧Image light

70‧‧‧Projection Module

72‧‧‧Projection optics

74‧‧‧Projection optics

76‧‧‧Projection optics

80‧‧‧Projected image light

100‧‧‧Lighting system

101‧‧‧Lighting system

102‧‧‧Lighting system

103‧‧‧Lighting system

104‧‧‧Light shot surface/component

105‧‧‧Light collecting optics / light collimating optics

106‧‧‧Reflective zone

107‧‧‧ optical axis

110‧‧‧First lens element

111‧‧‧second lens section

112‧‧‧First convex surface

113‧‧‧ Third lens section

114‧‧‧Light input surface

116‧‧‧First lens section

120‧‧‧second lens element

121‧‧‧Fourth lens section

122‧‧‧ second surface

123‧‧‧Sixth lens section

124‧‧‧ Third convex surface

125‧‧‧ fifth lens section

132‧‧‧ Wavelength selective reflector

134‧‧‧Reflective polarizer

136‧‧‧Optional retarder

140‧‧‧First light source

141a‧‧‧First color light

141c‧‧‧First converted light/output light

142a‧‧‧First Center Light

142b‧‧‧The first center reflected light / incident reflected light

142c‧‧‧First Center Conversion Ray/Converted Light

142d‧‧‧Transmission of converted light

142e‧‧‧Converted converted light/s polarized converted light

144a‧‧‧First boundary light

144b‧‧‧First boundary reflected light / incident reflected light

144c‧‧‧First boundary conversion ray/converted light

144d‧‧‧Transmission of converted light

144e‧‧‧Reflected converted light/s polarized converted light

146a‧‧‧first boundary ray/second boundary ray

146b‧‧‧First boundary reflected light / second boundary reflected light / incident reflected light

146c‧‧‧First boundary conversion ray/converted light

146d‧‧‧Transmission of converted light

146e‧‧‧Reflected converted light/s polarized converted light

150‧‧‧phosphor

155‧‧‧Encapsulation

156‧‧‧Bend surface

157‧‧‧Conical rod

158‧‧‧Composite parabolic concentrator (CPC)

170‧‧‧Light conversion zone/component

1A-1D show schematic cross-sectional views of a lighting system; FIGS. 2A-2C show schematic views of configurations near a light output area of a lighting system; and FIG. 3 shows a schematic view of an image projector.

100‧‧‧Lighting system

104‧‧‧Light shot surface/component

105‧‧‧Light collecting optics / light collimating optics

107‧‧‧ optical axis

110‧‧‧First lens element

111‧‧‧second lens section

112‧‧‧First convex surface

113‧‧‧ Third lens section

114‧‧‧Light input surface

116‧‧‧First lens section

120‧‧‧second lens element

121‧‧‧Fourth lens section

122‧‧‧ second surface

123‧‧‧Sixth lens section

124‧‧‧ Third convex surface

125‧‧‧ fifth lens section

132‧‧‧ Wavelength selective reflector

134‧‧‧Reflective polarizer

136‧‧‧Optional retarder

140‧‧‧First light source

141a‧‧‧First color light

141c‧‧‧First converted light/output light

142a‧‧‧First Center Light

142b‧‧‧The first center reflected light / incident reflected light

142c‧‧‧First Center Conversion Ray/Converted Light

142d‧‧‧Transmission of converted light

142e‧‧‧Converted converted light/s polarized converted light

144a‧‧‧First boundary light

144b‧‧‧First boundary reflected light / incident reflected light

144c‧‧‧First boundary conversion ray/converted light

144d‧‧‧Transmission of converted light

144e‧‧‧Reflected converted light/s polarized converted light

146a‧‧‧first boundary ray/second boundary ray

146b‧‧‧First boundary reflected light / second boundary reflected light / incident reflected light

146c‧‧‧First boundary conversion ray/converted light

146d‧‧‧Transmission of converted light

146e‧‧‧Reflected converted light/s polarized converted light

170‧‧‧Light conversion zone/component

Claims (22)

An illumination system comprising: a light emitting diode (LED) disposed on a substrate and configured to emit a first light beam in a first propagation direction to pass the first light beam through a collimating optics a wavelength selective reflector, in the collimating optics, the wavelength selective reflector for reflecting the first beam back through the collimating optics; and a phosphor disposed in close proximity The LED, the phosphor capable of downconverting a major portion of the first beam to become a second beam, the second beam propagating back in a second propagation direction to pass through the collimating optics and The wavelength selective reflector is passed through. The illumination system of claim 1, wherein the collimating optics comprises a first lens element adjacent to the substrate and a second lens element adjacent to the first lens element and opposite the substrate, the wavelength selective reflection The device is disposed on an outer surface of the first lens element or the second lens element or embedded in the first lens element or the second lens element. The illumination system of claim 1, wherein the wavelength selective reflector comprises a curved surface that is capable of focusing the first beam onto the phosphor. The illumination system of claim 1, further comprising a reflective polarizer disposed adjacent to the collimating optics and opposite the substrate, wherein the reflective polarizer is configured to direct a second polarization direction The second beam is reflected back to pass through the collimating optics to focus on the phosphor and to transmit the second beam in a first polarization direction. The illumination system of claim 1, wherein the collimating optics comprises an optical axis, and at least one of the LEDs or the phosphor is disposed on the optical axis. The illumination system of claim 1 wherein the phosphor comprises an encapsulated phosphor. The illumination system of claim 6, wherein the encapsulated phosphor comprises an encapsulant having a refractive index between about 1.2 and about 1.6. The illumination system of claim 6 wherein the encapsulated phosphor comprises an encapsulant having a refractive index between about 1.4 and about 1.5. The illumination system of claim 1, further comprising a low refractive index material between the LED and the collimating optic, the low refractive index material having a refractive index between about 1.0 and about 1.2. The illumination system of claim 9, wherein the low refractive index material is air. The illumination system of claim 1, wherein the first light beam comprises a first light ray propagating within a first collimation angle of the first propagation direction. The illumination system of claim 1, wherein the second light beam comprises a second light ray propagating within a second collimation angle of one of the second propagation directions opposite the first propagation direction. The illumination system of claim 6, wherein the encapsulated phosphor comprises a polydimethyl sulfoxide encapsulate. The illumination system of claim 1, further comprising a second LED disposed to directly emit a third beam toward the phosphor. The illumination system of claim 1, wherein the phosphorescent system is disposed on a reflective substrate. The illumination system of claim 1, further comprising a focusing optical element disposed between the phosphor and the collimating optic, the focusing optical element capable of focusing the first beam. The illumination system of claim 16, wherein the focusing optical element comprises a tapered glass rod or a compound parabolic concentrator (CPC). The illumination system of claim 4, further comprising a retarder disposed between the phosphor and the reflective polarizer. The illumination system of claim 18, wherein the retarder is a quarter wave retarder having a fast axis oriented at an angle of 22.5 degrees relative to a fast axis of the reflective polarizer. The illumination system of claim 4, wherein the reflective polarizer comprises a cholesteric reflective polarizer, a MacNeille type reflective polarizer, a wire grid reflective polarizer or a multilayer optical film (MOF) type reflector Chemist. The illumination system of claim 1, wherein the wavelength selective reflector comprises a blue reflector or an ultraviolet reflector. An image projector comprising: an illumination system comprising: a light emitting diode (LED) disposed on a substrate and configured to emit a first light beam in a first propagation direction to cause the first a beam of light passing through a collimating optics; a wavelength selective reflector in the collimating optic, the wavelength selective reflector for reflecting the first beam back through the collimating optics; a phosphor disposed adjacent to the LED, the phosphor capable of falling Frequency converting a major portion of the first light beam to cause it to become a second light beam, the second light beam propagating back in a second propagation direction to pass through the collimating optic and pass through the wavelength selective reflector; a polarization converter capable of converting the second beam into a third beam having a first polarization direction; an imager positioned to intercept the second beam in the first polarization direction; Projection optics.