JP5875865B2 - Device for recycling light to increase the brightness of light output, and LED projector incorporating the device - Google Patents

Description

  The present invention provides high brightness on the screen by efficiently combining light from one or more light sources with the output, and in particular, recycling using a light pipe with one or more light sources. Is related to a system and method for increasing brightness and for incorporating it into a projector.

  Light sources are used for all types of illumination and projection applications. Many applications require a high level of illumination system with a small effective emission range. Conventionally, this high level of brightness can be achieved by adding more light sources. However, this is technically impossible when the space for integrating a plurality of light sources is limited, and is economical when it is expensive to use a plurality of light sources integrated. Infeasible. Accordingly, the present invention is based on the desire to increase the brightness of light sources without increasing the number of light sources.

  For example, a micro display television (MDTV) has a possibility of realizing low cost with a large screen size. Conventional MDTVs are usually illuminated with arc lamps. This light source has the highest brightness at the lowest cost, but is not desirable in terms of the need for splitting white light into three colors and a short lifetime. With advances in LED technology, it is necessary to consider the use of LEDs as light sources in MDTVs in order to obtain other advantages such as long LED lifetimes and instant on. At present, however, LEDs have insufficient brightness for low-cost applications involving multiple small imaging panels or multiple larger screens. For example, referring to Zimmerman et al., US Pat. No. 6,057,049, an LED recycling scheme is utilized to increase the brightness of the light source. However, Zimmerman et al. Describe surrounding multiple LEDs in a light reflecting cavity with a single light exit. Also, Zimmerman et al., US Pat. No. 5,637, pp. 2, describes a fluorescent tube having a glass envelope with a phosphor coating surrounding a hollow interior filled with gas. A portion of the light produced by the phosphor coating material is recycled to the phosphor coating material. In particular, the present invention recycles using a light pipe with one or more light sources to increase brightness and incorporates it into a projector to efficiently transmit light from one or more light sources to the output section. Is based on the desire to provide high brightness on the screen.

US Pat. No. 6,869,206 US Pat. No. 6,144,536

  For example, LEDs are a type of light source that can be used in many lighting applications, such as general lighting and architectural lighting, as well as more recent projection televisions. Due to the low brightness of LEDs, most displays and projector systems have limited etendue, which typically limits the maximum output on the screen. For example, when used in a projector, in order to provide the necessary high light output on the projector screen, the LED must emit light at a high brightness level with a small effective light emitting area. Specifically, in order to be useful in projectors, LEDs must provide strong and bright light at a small solid angle within a small light emitting area in lumen measurement.

  While the development of light emitting diodes (LEDs) has made tremendous progress, the output brightness of currently available LEDs is still insufficient for most projection applications. Various methods have been proposed that combine primary color LEDs with output light recycling to increase brightness. However, most of these methods use expensive components and / or end up in large and bulky devices, which greatly limits their application. Therefore, the present invention uses a light pipe with one or more light sources (including but not limited to LEDs, arc lamps, UHP lamps, microwave lamps, etc.) that solve the above problems. This is based on the desire to provide a system and method for increasing the brightness by recycling, and a projector incorporating the system and method. The projector of the present invention can provide both color pixel displays and time sequential displays by further multiplexing a plurality of colors.

  Accordingly, it is an object of the present invention to provide a recycling system and method for increasing brightness using a light pipe with one or more light sources.

  Another object of the present invention is to provide a projector incorporating the aforementioned recycling system.

  According to an exemplary embodiment of the present invention, the recycling system and method increases the brightness of the light output by using at least one recycling light pipe with at least one light source. The output end of the recycling light pipe reflects the first portion of light to the light source, reflects the second portion of light to the input end of the recycling light pipe, and transmits the remaining portion of the light as an output. A recycling system is incorporated into the projector to provide a color projection image with increased brightness. The light source may be a white LED, a color LED, or a dual parabolic reflector (DPR) lamp.

  Various other objects, advantages and features of the present invention will become readily apparent from the following detailed description, and the novel features will be particularly pointed out in the appended claims.

  The following detailed description is provided by way of illustration and is not intended to limit the invention thereto. The detailed description will be best understood by reference to the accompanying drawings, wherein like components or features with different shapes are represented by like reference numerals.

1 is a perspective view of a recycling system including a light pipe 1000 according to an exemplary embodiment of the present invention. (A)-(c) is sectional drawing of the recycling system by one illustrative embodiment of this invention. 1 is a cross-sectional view of a recycling system according to an exemplary embodiment of the present invention with a six-side beam combiner and at least two light pipes. FIG. (A)-(c) are diagonal perspective views of a six-sided beam combiner coated with a semi-reflective coating or a spatially reflective portion, according to an illustrative embodiment of the invention. is there. 4 is a cross-sectional view of the recycling system of FIG. 3 incorporating at least two light pipes of FIG. 1 according to an exemplary embodiment of the present invention. 4 is a cross-sectional view of the recycling system of FIG. 3 incorporating at least two light pipes of FIG. 1 according to an exemplary embodiment of the present invention. FIG. 7 is a cross-sectional view of the recycling system of FIG. 6 with optical components arranged in a straight line, according to an illustrative embodiment of the invention. FIG. 8 is a cross-sectional view of the recycling system of FIGS. 6 and 7 with at least three light pipes of FIG. 1 according to an exemplary embodiment of the present invention. 2 is a perspective view of a recycling system comprising at least four light pipes of FIG. 1 and at least two six side beam combiners, according to an illustrative embodiment of the invention. FIG. 1 is a cross-sectional view of a recycling system with a beam combiner, two light pipes, and two DPR-based light sources, according to an illustrative embodiment of the invention. FIG. 1 is a perspective view of a beam combiner according to an exemplary embodiment of the present invention. FIG. 2 is a cross-sectional view of the recycling system of FIG. 1 with a reflective polarizer according to an exemplary embodiment of the present invention. FIG. 8 is a cross-sectional view of the recycling system of FIG. 7 with a reflective polarizer according to an exemplary embodiment of the present invention. FIG. 6 is a cross-sectional view of a recycling system comprising a tapered polarizing light pipe system and a DPR lamp according to another exemplary embodiment of the present invention. (A) is a cross-sectional view of the tapered polarizing light pipe system of FIG. 14 according to an exemplary embodiment of the present invention, and (b) is a taper of FIG. 15 (a) according to an exemplary embodiment of the present invention. It is a perspective view of the reflective opening of a type | mold light pipe system. FIG. 15 is a cross-sectional view of a recycling system comprising at least two tapered polarizing light pipe systems of FIG. 14 and a beam combiner, according to an illustrative embodiment of the invention. 1 is a cross-sectional view of an LED projector incorporating a recycling system according to an exemplary embodiment of the present invention. 1 is a cross-sectional view of an LED projector incorporating a recycling system according to an exemplary embodiment of the present invention. FIG. 19 is a cross-sectional view of the LED projector of FIG. 18 utilizing two LEDs, according to an illustrative embodiment of the invention. FIG. 4 is a perspective view of two and four LEDs mounted on a heat sink substrate, according to an illustrative embodiment of the invention. 1 is a cross-sectional view of a recycle reflector as a solid optical component, according to an illustrative embodiment of the invention. FIG. 1 is a cross-sectional view of an optical projector with a lenslet array, according to an illustrative embodiment of the invention. 1 is a cross-sectional view of an optical projector with a lenslet array, according to an illustrative embodiment of the invention. 1 is a cross-sectional view of an optical projector with a lenslet array, according to an illustrative embodiment of the invention. 1 is a cross-sectional view of a recycling system with a beam splitter / combining (BSC) system, according to an illustrative embodiment of the invention. FIG. 1 is a cross-sectional view of a recycling system with a beam splitter / combining (BSC) system, according to an illustrative embodiment of the invention. FIG. 1 is a cross-sectional view of a recycling system with a beam splitter / combining (BSC) system, according to an illustrative embodiment of the invention. FIG. FIGS. 3A to 3F are diagrams illustrating various configurations of LEDs or LED chips according to an exemplary embodiment of the present invention. 1 is a cross-sectional view of an RGB sequential projector according to an exemplary embodiment of the present invention. 1 is a cross-sectional view of a light source according to an exemplary embodiment of the present invention.

  Next, exemplary embodiments of the present invention will be described with reference to the drawings. These embodiments are illustrative of the principles of the invention and should not be construed as limiting the scope of the invention.

  By efficiently combining light from one or more light sources with the output, high brightness is obtained at the screen. While a standard lighting system cannot increase the brightness of a light source, the present invention takes advantage of the recycling and combining of light sources to provide higher output intensity at the screen. The present invention increases the output from one or more light sources by recycling and combining the output from one or more light sources. Light sources applicable to various configurations and embodiments of the present invention include arc lamps, UHP lamps, LEDs, microwave lamps, and the like.

  Referring now to FIG. 1, a recycling system 1000 with a light pipe 1100, which is an exemplary embodiment of the present invention, is shown. The light pipe 1100 may be solid or hollow. The light pipe 1100 may be linear or tapered. The input end 1200 of the light pipe 1100 includes a reflective input surface or reflective input unit 1210 and an input port or transmissive unit 1220. The reflective input surface 1210 comprises a part or part of an input end 1200 that is reflective to reflect light, and the input port 1220 is transparent to allow input light to pass through the light pipe 1100. It consists of 1200 remainders or remainders. According to one aspect of the present invention, the input port 1220 may be rectangular, circular, or any suitable shape, and the reflective input surface 1210 may be a waveplate (not shown) for supporting polarized optics. May be provided.

  The output end 1300 of the light pipe 1100 includes a reflective output surface or reflective output unit 1310 and an output port or transmissive output unit 1320. The reflective output surface 1310 comprises a part or part of the output end 1300 that is reflective to reflect light, and the output port 1320 is an output that is transparent to transmit or output light from the light pipe 1100. It consists of the remaining part or the remaining part of the end 1300. According to one aspect of the invention, the output port 1320 may be rectangular, circular, or any suitable shape, and the reflective output surface 1310 may be a waveplate (not shown) for supporting polarized optics. May be provided.

  According to an exemplary embodiment of the present invention, the output port 1320 may have a shape that matches the shape and size required for the illumination or projection system. For example, the output port 1320 may be circular or rectangular with an aspect ratio of 6: 9 or 4: 3. Input light that enters the light pipe 1100 from the input port 1220 is transmitted to the output end 1300 of the light pipe 1100, and part of the light is output from the light pipe 1100 through the output port 1320. That is, a part of the light is reflected by the input end 1200 and a part is output from the light pipe 1100 via the output port 1320. The light pipe 1100 reflects a part of the light from the input port 1220 and sends it to the output port 1320. The light source that can be used at the input port 1220 is an output from an LED, a light pipe, an output from a phosphor excited by an LED or a laser, or an output from an up-converting material pumped by an LED or a laser. It may be. The light source may also be an arc lamp, a microwave lamp, or a lamp with a reflector.

  FIGS. 2A to 2C show various examples of the recycling system 1000 according to the embodiment of the present invention. FIG. 2 (a) shows a cross-sectional view of a recycling system 1000 including a tapered light pipe 1100 provided with LEDs 1400. Light input to the tapered light pipe 1100 is from the LED 1400. The output end 1300 of the tapered light pipe 1100 includes an output port 1320 for transmitting a part of the light and a reflective output surface 1310 for recycling the remaining part of the light. Output light from the LED 1400 is coupled to the tapered light pipe 1100, and a part of this light is reflected by the LED 1400. As the light output returns into the tapered light pipe 1100, some of the light is reflected (or recycled) by the LED 1400.

  FIG. 2B is another example of a recycling system 1000 in which the input end 1200 of the tapered light pipe 1100 is larger than the LED 1400 according to an embodiment of the present invention. Light entering the tapered light pipe 1100 is from the LED 1400. The output end 1300 of the tapered light pipe 1100 includes an output port 1320 for transmitting a part of the light and a reflective output surface 1310 for recycling the remaining part of the light. As shown in FIG. 1, the surplus range or reflective input surface 1210 at the input end 1200 is reflective to recycle a portion of the light.

  FIG. 2 (c) shows an example of a recycling system 1000 according to an embodiment of the present invention. In this case, input light to the light pipe 1100 is, for example, a dual parabolic reflector system, an elliptical system, or the like. It is from an input light pipe 1500 coupled from a light source (similar to the light pipe 1100, it may be linear, tapered, hollow, solid). Although not shown in the figure, the recycling system 1000 may be an LED, a microwave lamp, a short wavelength LED or a phosphor excited with a laser, or an up-converting material pumped with a long wavelength LED or laser. ) Etc., but other light sources can be used.

Next, FIG. 3 illustrates a recycling system 2000 according to an exemplary embodiment of the present invention. The recycling system 2000 includes a six-sided beam / optical coupler 2100 and at least two light pipes (indicated by reference numerals LP ₁ and LP ₂ ). LP ₁ and LP ₂ are substantially the same as the light pipe 1100 of the recycling system 1000 of FIG. The recycling system 2000 can combine a plurality of light sources. In FIG. 3, the output of the recycling system 2000 is a combination of two light sources. Each light source 2200 includes an LED 1400 (indicated by reference numerals of LED ₁ and LED ₂ ) and a light pipe LP ₁ or LP ₂ . Light from LED ₁ (1400) is coupled to LP ₁ (1100) and further enters the optical coupler 2100. All six sides of the optical coupler 2100 are polished so that they can be used for both transmission and total internal reflection (TIR). The triangular surface 2400 of the optical coupler 2100 is also polished so that the optical coupler 2100 functions as a waveguide and can guide light from the light pipes LP ₁ and LP ₂ (1100). According to an exemplary embodiment of the present invention, the diagonal surface 2110 of the beam combiner 2100 is coated to provide a semi-reflective / transmissive surface. The diagonal surface 2110 is covered with a semi-reflective coating as shown in FIG. 4 (a), or is provided with a spatially reflective portion as shown in FIGS. 4 (b) and 4 (c). be able to. The ratio of reflection and transmission can be optimized for the maximum output for each application. According to one aspect of the present invention, beam combiner 2100 with all six sides / faces / surfaces polished functions as a waveguide rather than as a bulk optical system. The size of the output of LP ₁ (1100) matches the surface size of the beam combiner 2100. Part or part of the light from LP ₁ (1100) is reflected to LP ₂ (1100) and recycled by LED ₂ (1400). Part or part of the light from LP ₂ (1100) is reflected to LP ₁ (1100) and recycled by LED ₁ (1400). Part or a part of the light from LP ₁ , LP ₂ (1100) is emitted as output light from the output port 2130 of the recycling system 2000, and the remaining part of the light is reflected by the end reflector 2120 and returned to the recycling system 2000. It is. The recycling system 2000 can optionally include a reflective surface or reflector 2140 that reflects a portion of the light output and returns it to the recycling system 2000 to recycle a portion of this light output. In accordance with an exemplary embodiment of the present invention, to further promote TIR, the recycling system 2000 may include LP ₁ (1100) and beam combiner 2100, LP ₂ (1100) and beam combiner 2100, and so on. An air gap or low index glue 2300 is optionally provided between one or more optical components.

Next, FIGS. 5 and 6 illustrate the recycling system 2000 of FIG. 3 incorporating the light pipe 1100 of FIG. 1, according to an illustrative embodiment of the invention. Here, the repeated description of the optical components common to the recycling system 1000 of FIG. 1 and the recycling system 2000 of FIGS. 3, 5, and 6 is omitted. In FIG. 5, each LED 1400 (LED ₁ , LED ₂ ) is coupled to or covers a part or part of the input end 1200 of the light pipe 1100 (LP ₁ , LP ₂ ). The remaining portion or the remaining portion of the input end 1200 is coated with a reflective coating to provide a reflective input surface 1210. The output of the recycling system 2000 of FIG. 5 is a combination of two LED inputs. In FIG. 6, another light source is used instead of the LED 1400 (LED ₁ , LED ₂ ) of FIG. This light source includes, but is not limited to, output from light pipes, illumination lamps (arc lamps, microwave lamps, etc.) focused by a reflector or lens or the like. Alternatively, according to one exemplary embodiment of the present invention, the optical components of the recycling system of FIG. 6 can be arranged in a straight line as shown in FIG. In accordance with an exemplary embodiment of the present invention, to further promote TIR, the recycling system 2000 of FIGS. 5-7 uses LP ₁ (1100) and beam combiner 2100, LP ₂ (1100) and beam. A gap 2 or low index glue 2300 is provided between one or more optical components, such as a coupler 2100.

  According to an exemplary embodiment of the present invention, as shown in FIG. 8, the recycling system 2000 of FIG. 6 or 7 may comprise at least three light pipes of FIG. That is, instead of the end reflector 2120 of the recycling system 2000 of FIG. 6 or FIG. 7, the light pipe 1100 is used in FIG. The output of the recycling system 2000 in FIG. 8 is a combination of three light sources. Light sources that can be used at the input 1220 include LEDs, output from light pipes, output from phosphors excited with LEDs or lasers, or up-converting materials pumped with LEDs or lasers, etc. May be output. In one exemplary embodiment of the present invention, in order to further promote TIR, the recycling system 2000 of FIG. 8 uses a low index glue or low index glue between one or more optical components. ) 2300 is optionally provided.

According to an exemplary embodiment of the invention, FIG. 9 shows a recycling system 3000 comprising at least four light pipes 1100 and at least two beam combiners 2100. The recycling system 3000 combines outputs from at least four sets of light sources to obtain a single output. Although FIG. 9 shows a recycling system 3000 with two beam combiners 2100, it is understood that the recycling system 2000 of FIG. 9 may include more than one beam combiner 2100. According to one aspect of the present invention, the directions of the diagonal planes 2110 of the two beam combiners 2100 are different. The direction of the diagonal face 2110 of the beam combiner (1) is oriented to recycle light, and the direction of the diagonal face 2110 of the beam combiner (2) is oriented to output light. The triangular surface 2400 of the beam combiner 2100 is polished so that the beam combiner 2100 can function as a waveguide to guide light from the four light pipes 1100 (LP ₁ , LP ₂ , LP ₃ , LP ₄ ). Has been. In an exemplary embodiment of the present invention, to further promote TIR, the recycling system 3000 of FIG. 9 includes LP ₁ (1100) and beam combiner (1), LP ₂ (1100) and beam combiner ( A gap or low index glue 2300 is provided between one or more optical components, such as 1).

Referring now to FIG. 10, a recycling system 4000 comprising a beam combiner 2100, two light pipes 1100, and two light sources 4200 according to an exemplary embodiment of the present invention is shown. The light source 4200 is a dual parabolic reflector (DPR) lamp. The first light source DPR lamp ₁ 4200 is coupled to the first tapered light pipe TLP ₁ (1100), which in turn is coupled to the input port 1220 of the light pipe LP ₁ (1100). The second light source DPR lamp ₂ 4200 is coupled to the second tapered light pipe TLP ₂ (1100), which in turn is coupled to the input port 1220 of the light pipe LP ₂ (1100). Operation of the light pipe 1100 _(LP 1, LP ₂₎ and the beam combiner 2100 of the recycling system 4000, light pipe 1100 _(LP 1, LP ₂₎ of recycling system 2000 of FIG. 6-7 with those of the beam combiner 2100 It is the same. The recycling system 4000 uses the beam combiner 2100 to combine the output of the second set of light sources 4200 with the first set of light sources 4200 to obtain one output. In accordance with an exemplary embodiment of the present invention, to further promote TIR, the recycling system 4000 of FIG. 10 may include, for example, LP ₁ (1100) and beam combiner 2100, TLP ₂ (1100) and LP ₂ ( 2100), or a low index glue 2300 between one or more optical components.

  According to an exemplary embodiment of the present invention, as shown in FIG. 11, the output surface or output surface 2500 of the beam combiner 2100 of the present recycling system (2000, 3000, 4000) is a transparent opening or A reflective output surface 2500 with an output port 2130. According to one aspect of the present invention, the shape, size, and location of the output port 2130 can be configured to suit the needs of each application.

  Referring now to FIG. 12, according to an exemplary embodiment of the present invention, the recycling system 1000 of FIG. 1 includes a reflective polarizer coupled to the output port 1320 of the light pipe 1110 to provide a polarized output. 1600 is further provided. According to one aspect of the present invention, the reflective input surface 1210 of the light pipe 1100 can increase efficiency by optionally including a wave plate 1230.

  According to an exemplary embodiment of the present invention, as shown in FIG. 13, the recycling system 2000 of FIG. 7 is a reflective polarizer coupled with an output port 2130 of a beam combiner 2100 to provide a polarized output. 1600 is further provided. According to one aspect of the present invention, the reflective input surface 1210 of the light pipe 1100 can optionally include a wave plate 1230 to increase efficiency. The beam combiner 2100 of the recycling system 2000 of FIG. 13 can combine two separate light sources to produce a single polarized light output.

14, 15 (a), and (b), a recycling system 5000 according to an exemplary embodiment of the present invention is shown. The recycling system 5000 includes a tapered polarizing light pipe system 5100 with a recycling process configured to use a DPR lamp or system 4200. The tapered polarizing light pipe 5100 has two common tapered light pipes 1100 (TLP ₁ , TLP) having a common surface that is transparent and preferably filled with index matching adhesive, epoxy, or fluid 5500. ₂ ). Input light entering the tapered light pipe 1100 (TLP ₁ ) is coupled into the tapered light pipe 1100 (TLP ₂ ) and output from the TLP ₂ as a polarized output. A part or a part of the output light is reflected by a reflection port 5300 that is optionally provided. An example of the output reflection port is shown in FIG. 15B, but the shape and size of the transmissive opening 5310 can be changed according to the application. Unused polarized light is reflected by the reflective polarizer 5400 and returned to the DPR lamp 4200. The TLP ₂ 1100 of the tapered polarizing light pipe system 5100 includes a reflective surface 5200 optionally provided with a wave plate 5210 for reflecting a portion of the light back to the reflective polarizer 5400.

  According to an exemplary embodiment of the present invention, the recycling system 6000 of FIG. 16 includes a beam combiner 2100 and at least two tapered polarizing light pipe systems 5100 of FIG. 15 that function as light sources. Since the outputs of the two tapered polarizing light pipe systems 5100 in FIG. 16 are coupled to the beam combiner 2100, the tapered polarizing light pipe system 5100 in FIG. 16 has a reflective polarizer 5400 and an optional reflector 5300. Is not necessary. The output end of the beam combiner 2100 in FIG. 16 includes a reflective polarizer 6100 and optionally a reflective aperture 6200, which includes a reflective polarizer 5400 and a transmissive aperture 5310, optionally reflective aperture. It is the same as 5300. Although not shown in FIG. 16, each of the tapered polarizing light pipe systems 5100 of FIG. 16 can be combined with a DPR lamp 4200 as shown in FIG. The beam combiner 2100 of the recycling system 6000 can combine at least two light sources 5100 to obtain a single polarized output beam. The recycling system 6000 can combine two or more light sources 5100 using one or more beam combiners 2100, similar to the recycling system 300 of FIG.

  LED projection systems are advancing rapidly as LED power increases. A typical LED projection system uses three color LEDs of red, green and blue. The outputs from each LED are combined into one output for multiplexing in time series to produce a color output image. Three-color LEDs are made of different materials and have different temperature dependencies. Feedback control is required to maintain a uniform color on the screen, which makes a typical LED projection system expensive and complex. Conventional illumination using white LEDs has been considered inferior in color because the white LEDs do not contain a sufficient red component.

  The present invention overcomes these limitations by using white LEDs in conventional illumination and projection systems. According to an exemplary embodiment of the present invention, a recycled white LED projector is obtained that emphasizes red. Referring now to FIG. 17, a projector 7000 incorporating a recycling system according to an exemplary embodiment of the present invention is shown. The projector 7000 includes an imager panel 7300, a projection engine 7100, a projection lens 7200, and a relay lens 7400. Projector 7000 uses the light emitted by LED 1400, but a portion of this emitted light is returned to LED 1400 for recycling, and the recycling system 1000 is used to increase brightness. Although FIG. 17 shows a projector 7000 that incorporates a recycling system 1000, it is understood that the projector 7000 can incorporate any of the recycling systems described herein. The output of the tapered light pipe 1100 is coupled into the projection engine 7100 via a relay lens 7400 and a color wheel 7500 to form a sequential color system.

  The LED 1400 may be a white phosphor LED 1400, LED or laser, preferably a white phosphor pumped with blue or ultraviolet (UV) light. It is understood that the LED 1400 is not limited to a white LED, and the present invention can utilize a color LED to provide an LED projector with a color enhancement function as described herein. The LED 1400 is preferably mounted on the heat sink substrate 1410. The output of the LED 1400 is coupled into the light pipe 1100, which may be hollow or solid, or tapered or linear, so that the output is suitable for a particular application. The light pipe 1110 is arranged and arranged at the output part of the LED 1400 so as to obtain the maximum coupling efficiency. A portion of the surface of the output end 1300 of the light pipe 1100 is covered by a reflective coating 1310 or using a mirror or reflector 1310 so that only 1% of the output of the light pipe 1100 passes through the color wheel 7500. To the projection engine 7100. Next, using the relay lens 7400 and the projection engine 7100, the output portion of the light pipe 1110 is projected onto the imaging panel or the imager panel 7300. Next, a final image on the imaging panel 4300 is projected on a screen (not shown) through the projection lens 7200.

  According to an exemplary embodiment of the present invention, the output of light pipe 1110 is coated with an output coating that reflects only selected wavelengths and transmits all remaining wavelengths of light, thereby providing the desired It is possible to emphasize the color. For example, the output end 1300 of the light pipe 1100 can be coated to reflect blue light and transmit all remaining light colors. In other words, the recycling system 1000 emphasizes other colors transmitted to the projection engine 7100 by promoting the recycling of blue light.

  According to an exemplary embodiment of the present invention, the color wheel 7500 includes two or more filters with different color filters such as red, blue, green, or red, green, blue, colorless in a three color system. It has a segment. Therefore, the color projector 7000 uses a sequential color system that continuously displays each color to generate a color image.

  According to an exemplary embodiment of the present invention, the LED 1400 is DC driven. Alternatively, the LED 1400 can be driven with a variable current synchronized with the color wheel 7500. For example, the LED 1400 can have different current values as a function of which color segment of the color wheel 7500 is in front of the light pipe 1100. In certain embodiments, a higher current is added when there is a red segment in front of the light pipe to overcome the red defect with a higher current.

  According to an exemplary embodiment of the present invention, imager panel 7300 may be a digital mirror device (DMD), such as manufactured by Texas Instruments or other manufacturers. According to an exemplary embodiment of the present invention, the imager panel 7300 may be a reflective liquid crystal display (LCOS) panel in which liquid crystal is formed on a silicon substrate. The recycling system 1000 of FIG. 17 can include an optional reflective polarizer 5400 that can reflect the polarization of unwanted light back to the light pipe 1100 for recycling. Arranged at the output end 1300 of the light pipe 1100.

  According to an exemplary embodiment of the present invention, the white phosphor of LED 1400 can be driven by the blue light emitted by LED 1400. In the process of recycling in the recycling system 1000, after the recycled blue light is reabsorbed by the phosphor of the LED 1400, it can be emitted again as green and red light. As a result, the recycled light will have a low blue output and a high red and green output.

  According to an exemplary embodiment of the present invention, for applications requiring higher output power, projector 7000 utilizes a plurality of LEDs 1400 to drive one or more phosphor segments to emit. The emitted light can be coupled into the light pipe 1100 of the recycling system 1000. It is understood that the output from multiple LEDs 1400 can also be combined with a prism, light pipe, or other equivalent optical component that functions as a waveguide, resulting in a higher output on a screen (not shown). The For example, a prism can function as a waveguide when its side surfaces are polished to be reflective to promote TIR.

The advantages of using light from a white phosphor LED are as follows.
1. White phosphor LEDs have shorter wavelengths and larger band gaps, so they can operate at higher junction temperatures and relax the heat sink requirements.
2. Since monochromatic LEDs can be used, it is not necessary to multiplex multi-color LEDs.
3. The color wheel is an excellent component developed and has a very long lifetime.
4). Standard projection engine configurations can be used, and many manufacturers have experience in mass production of such standard projection engines.
5). Many manufacturers produce white phosphor LEDs.
6). By using a plurality of smaller white phosphor LEDs, a wide emission range can be obtained. This emission range is free of voids between LEDs that can reduce recycling efficiency.

  Referring now to FIG. 18, there is shown an LED projector 8000 further comprising a recycling reflector 8100 for recycling light, according to an illustrative embodiment of the invention. The recycle reflector 8100 reflects a part of the LED output and returns it to the LED 1400 to recycle the light. The LED 1400 may be a white or color LED. Preferably, the recycle reflector 8100 is a spherical, annular, elliptical reflector that returns the image of the LED to the LED itself. The opening of the recycle reflector 8100 is used as the output port 1320. According to one embodiment of the present invention, different recycling amounts can be achieved by changing the size of the opening. The light output is combined into a light pipe 1100 after being combined using a condenser lens 7600 or a lens system comprising two or more lenses 7600. This light is homogenized by the light pipe 1100 to generate a uniform light intensity profile at the output of the light pipe 1100. The remaining optical components of the LED projector 8000 are similar to those of the LED projector 7000 of FIG. The color wheel 7500 can be disposed at either the input end or the output end of the light pipe 1100.

  According to an exemplary embodiment of the invention, FIG. 19 shows an LED projector 8000 that utilizes two or more LEDs 1400. The recycle reflector 8100 images one LED on another LED to increase the recycle efficiency of the LED projector 8000. FIG. 20 shows two or four LEDs 1400 mounted on a heat sink substrate 1410 that can be used with an LED projector 8000. In a case where four LEDs are mounted, the recycle reflector 8100 images the first LED on a second LED positioned obliquely with respect to the first LED, for example, LED A is above LED A 'and LED B' Images on LED B. A condenser lens 7600 couples the light output of the LED 1400.

  According to an exemplary embodiment of the present invention, the recycle reflector 8100 may be a solid optical component as shown in FIG. 21, for example, a half-optimized curvature for maximum power efficiency. It may be a piece of glass having a reflective translucent surface. The solid glass 8100 arranged at the output portion of the LED 1400 is arranged so that light can be recycled to the maximum. A part of the output surface of the solid glass 8100 is covered with a reflective coating material so as to be a reflective surface 8110, and the remaining part is transmissive so as to function as an output port 8120. The output port 8120 can be formed from the same continuous surface as the reflecting surface 8120, and can be configured to have different curvatures for optimal coupling.

  Referring now to FIGS. 22-24, an LED projector 8000 is shown configured with the light pipe 1110 omitted to reduce manufacturing costs, according to an illustrative embodiment of the invention. Here, a lenslet array 8200 is used instead of the condenser lens 7600 of the LED projector 8000 of FIG. The lenslet array 8200 may be circular as shown in FIG. 7 or rectangular as shown in FIG. 8, and is composed of two or more lenses or lenslets. The lenslets can be arranged in a standard row or randomly, and can be configured in a specific pattern for maximum efficiency and uniformity. Each lenslet images the LED on plane A (as shown in FIG. 22). It will be appreciated that this point on the plane A is substantially in the same position as the output end or output surface 1300 of the light pipe 1100. Since this point on the plane A is composed of an image formed by each lenslet, the entire intensity profile can be made uniform. This output is then coupled to a projection screen (not shown) via imaging panel 7300, projection engine 7100, and projection lens 7200. According to one aspect of the present invention, the lenslet array 8200 can convert a square LED 1400 into a rectangular output that fits various projected aspect ratio formats. In general, the output pattern can be any size, shape, and intensity profile required.

  In accordance with an exemplary embodiment of the present invention, recycling with a beam splitter / combining (BSC) system 9100 with all surfaces / surfaces polished reflectively to facilitate TIR and two LEDs 1400 A system 9000 is shown in FIG. In accordance with one aspect of the present invention, the BSC 9100 comprises two triangular prisms (all faces / surfaces polished reflectively to promote TIR) that contact at a semi-reflective interface 9120. Yes. The semi-reflective interface 9120 can be created by coating with a semi-reflective coating or by using a surface partially coated with a reflective coating. It will be appreciated that the reflectivity can be controlled by the size of the coated surface area. For example, the semi-reflective interface 9120 may comprise reflective stripes 9125 (not shown) or reflective dots (not shown).

  The output from LED 1400 is coupled into BSC 9100. A part of the light from the LED 1400 is reflected as output to the output end 1300 of the light pipe 1100, a part is sent to another LED 1400, and the remaining part is sent toward the reflective surface of the BSC 9100. It is understood that the BSC 9100 functions as a waveguide because all six sides thereof are polished, preferably reflectively polished, to promote TIR. In general, light emitted from the LED 1400 and not sent as an output to the output end of the light pipe 1100 is recycled and finally output from the light pipe 100 as an output. Depending on the specific application, the output from the BSC 9100 can be used as is or coupled via an output light pipe output (not shown) that can be straight, tapered, hollow or solid. Can be made. The light pipe 1100 and the output light pipe (not shown) may be a standard light pipe or a recycled light pipe with a semi-reflective output surface 1610, and further to LCOS, LCD, or other polarization dependent systems. A reflective polarizer 1600 can be provided at the output end 1300 to provide a polarized output.

  The recycling system 9000 includes a waveguide system with a BSC 9100, two LEDs 1400, and a light pipe 1100, but the recycling system 9000 can be expanded to include a network of waveguides. In accordance with an exemplary embodiment of the present invention, FIG. 26 shows a recycling system 9000 with two LEDs, in which the LEDs are waveguides (light pipe 1100, polished on all sides, Preferably, it is disposed on the same plane as the triangular prism 9200 reflectively polished to promote TIR and BSC 9100) with a reflective surface 9110). FIG. 27 shows a recycling system 9000 with three LEDs, which includes three LEDs 1400, two light pipes 1100, two BSCs 9100 with a reflective surface 9110, and one triangular prism 9200. The recycling system 9000 is not limited to one, two, or three LEDs, but can use a network of waveguides (light pipe 1100, triangular prism 9200, BSC 9100) to recycle multiple LEDs together. It is understood that you can.

According to one exemplary embodiment of the present invention, FIGS. 28 (a)-(f) show variously shaped LEDs or LED chips 1400. The LED or LED chip 1400 with the symbol “C” indicates that the LED chip 1400 is a color chip, and the color may be white, red, green, blue, or any other color LED chip. Depending on the imaging properties of the recycle reflector 8100, each of the paired LEDs is imaged on top of each other and recycled, but is preferably a pair of LEDs of the same color. For example, in FIG. 28C, the imaging pairs C ₁ and C ₁ ′ are the same color, and the imaging pairs C ₂ and C ₂ ′ are the same color. FIG. 28 (e) shows the red (R), green (G), and blue (B) LED versions of FIG. 28 (c), and the imaging pairs in this case are (R, R ′), (B, B ′). ), (G, G ′). FIG. 28D and FIG. 28F show another combination of LED chip arrays. It is understood that other LED chip combinations and structures are possible and are considered to be encompassed by the present invention. It should be noted that the specific LED chip arrangement varies depending on the application of the present recycling system.

  Referring now to FIG. 29, there is shown an RGB sequential projection system or RGB sequential projector 9500 according to an illustrative embodiment of the invention. The RGB sequential projector 9500 includes a projection engine 7100, an imaging panel 7300, a projection lens 7200, a relay lens 7400, a light pipe 1100, a recycle reflector 8100, an RGB LED 1400, and a lenslet array 8200. The RGB sequential projector 9500 can time-multiplex three types of colors and use the imaging panel 7300 for pixel intensity control to generate a color image on a screen (not shown). The output of the RGB LED 1400 is recycled by a recycle reflector 8100 and combined using the lens, lenslet array and / or lens array 8200 described herein. It will be appreciated that the color wheel 7500 is not required since the RGB LED 1400 can be time multiplexed and is therefore not shown in FIG.

  According to an exemplary embodiment of the present invention, as shown in FIG. 30, a light source 9600 can be used for LED 1400 mounted on a heat sink substrate 1410, a recycle reflector 8100, and general purpose lighting. Or any lens system 9650 that can be incorporated into the various projectors described herein. The LED 1400 may be a single color or multi-color LED 1400. The lens system 9650 can be configured to diffuse the light output at a predetermined angle. According to one aspect of the invention, the lens system 9650 can be configured such that the light output is focused into the object, such as the light pipe 1100 of the projector 9500.

  According to an exemplary embodiment of the present invention, the light source 9600 includes a diffuser 9610 that is inserted before or after the lens system 9650 and optionally provided to allow further adjustment of the light output profile. it can. The diffuser plate 9650 may be ground glass, a holographic diffuser plate, or a lens array. According to an exemplary embodiment of the present invention, the recycle reflector 8100, the lens system 9650, and the optional diffuser 9610 can be molded into plastic or glass as a single unit, which facilitates assembly and manufacture. Cost can be reduced.

  According to an exemplary embodiment of the present invention, the lens system 9650 can be configured to collimate the light, so that the light source 9600 can replace a standard lamp with a parabolic reflector. . According to one aspect of the invention, the light source 9600 can replace a standard lamp with an elliptical reflector because the lens system 9650 can be configured to focus light. According to one aspect of the present invention, the lens system 9650 can be configured to diffuse light, so that the light source 9600 can replace a standard lamp for a general purpose spotlight. It will be appreciated that the lens system 9650 can further comprise an optional diffuser 9610, which allows further adjustment of the light output profile and provides optimal results.

  Although the present invention has been described above, those skilled in the art will appreciate that various modifications can be made without departing from the spirit and scope of the present invention. All such modifications are intended to be included within the scope of the claims.

Claims (31)

A device that recycles light to increase the brightness of the light output,
It has a light pipe for recycling with an input end and an output end,
The input end of the recycling light pipe includes an input port for receiving input light from a light source, and a reflective input surface,
The output end of the recycling light pipe reflects an output port for outputting light from the recycling light pipe and a part of the light directed to the output end to the input end of the recycling light pipe. With a reflective output surface,
The input port transmits a portion of the light reflected by the reflective output surface to the light source for recycling, and the reflective input surface reflects the remaining portion of the light to the output end of the recycling light pipe. This increases the brightness of the light emitted from the output port through light recycling,
Further comprising: at least two light sources; at least two recycling light pipes; and a six-sided beam combiner that combines the outputs of the at least two recycling light pipes to generate one output beam;
Each of the six side surfaces of the beam combiner is polished to promote total internal reflection so that the beam combiner can function as a waveguide,
The apparatus wherein the beam combiner comprises a diagonal surface coated to provide a semi-reflective surface. A device that recycles light to increase the brightness of the light output,
It has a light pipe for recycling with an input end and an output end,
The input end of the recycling light pipe includes an input port for receiving input light from a light source, and a reflective input surface,
The output end of the recycling light pipe reflects an output port for outputting light from the recycling light pipe and a part of the light directed to the output end to the input end of the recycling light pipe. With a reflective output surface,
The input port transmits a portion of the light reflected by the reflective output surface to the light source for recycling, and the reflective input surface reflects the remaining portion of the light to the output end of the recycling light pipe. This increases the brightness of the light emitted from the output port through light recycling,
Further comprising at least four light sources, at least four recycling light pipes, and at least two six-sided beam combiners;
The diagonal surface coated to provide the semi-reflective surface of the first beam combiner is oriented to recycle light and the diagonal surface coated to provide the semi-reflective surface of the second beam combiner. An apparatus, wherein a plane is oriented to output light from the apparatus, and the orientation of the diagonal faces of the first and second beam combiners are different from each other. A device that recycles light to increase the brightness of the light output,
It has a light pipe for recycling with an input end and an output end,
The input end of the recycling light pipe includes an input port for receiving input light from a light source, and a reflective input surface,
The output end of the recycling light pipe reflects an output port for outputting light from the recycling light pipe and a part of the light directed to the output end to the input end of the recycling light pipe. With a reflective output surface,
The input port transmits a portion of the light reflected by the reflective output surface to the light source for recycling, and the reflective input surface reflects the remaining portion of the light to the output end of the recycling light pipe. This increases the brightness of the light emitted from the output port through light recycling,
A reflective polarizer at the output end of the recycling light pipe;
The light pipe for recycling includes first and second tapered light pipes having a common surface filled with index matching glue, epoxy, and fluid.
Input light entering the first tapered light pipe is coupled into the second tapered light pipe;
The reflective polarizer increases the brightness of the light output by reflecting unused polarized light back to the light source for recycling. A device that recycles light to increase the brightness of the light output,
It has a light pipe for recycling with an input end and an output end,
The input end of the recycling light pipe includes an input port for receiving input light from a light source, and a reflective input surface,
The output end of the recycling light pipe reflects an output port for outputting light from the recycling light pipe and a part of the light directed to the output end to the input end of the recycling light pipe. With a reflective output surface,
The input port transmits a portion of the light reflected by the reflective output surface to the light source for recycling, and the reflective input surface reflects the remaining portion of the light to the output end of the recycling light pipe. This increases the brightness of the light emitted from the output port through light recycling,
Further comprising at least two light sources and a reflective polarizer at the output end of each recycling light pipe;
Each recycling light pipe includes first and second tapered light pipes having a common surface filled with index matching glue, epoxy, and fluid,
Input light entering the first tapered light pipe is coupled into the second tapered light pipe;
The apparatus wherein the reflective polarizer of each recycling light pipe increases the brightness of the light output by reflecting unused polarized light and returning it to the corresponding light source for recycling. A device that recycles light to increase the brightness of the light output,
It has a light pipe for recycling with an input end and an output end,
The input end of the recycling light pipe includes an input port for receiving input light from a light source, and a reflective input surface,
The output end of the recycling light pipe reflects an output port for outputting light from the recycling light pipe and a part of the light directed to the output end to the input end of the recycling light pipe. With a reflective output surface,
The input port transmits a portion of the light reflected by the reflective output surface to the light source for recycling, and the reflective input surface reflects the remaining portion of the light to the output end of the recycling light pipe. This increases the brightness of the light emitted from the output port through light recycling,
At least two light sources each of which is an LED;
A six-sided beam splitter / combiner (BSC) system that provides a reflective surface and that is reflectively polished on all sides to facilitate total internal reflection (TIR) so that it can function as a waveguide. ,
The BSC system reflects a first portion of light from each LED as an output to the output end of the recycling light pipe and a second portion of light from each LED to another LED for recycling. And further directing other portions of the light from each LED toward the reflective surface of the BSC system.   2. The recycling light pipe according to claim 1, wherein the recycling light pipe is one of a hollow straight light pipe, a hollow taper light pipe, a solid straight light pipe, and a solid taper light pipe. Equipment.   The apparatus according to claim 1, wherein the shape of the input port is a rectangle or a circle, and the shape of the output port is a rectangle or a circle having an aspect ratio of 6: 9 or 4: 3.   The apparatus of claim 1, wherein at least one of the reflective input surface and the reflective output surface of the recycling light pipe comprises a wave plate.   The light source may be a dual parabolic reflector (DPR) lamp coupled to a light pipe, a white LED, a color LED, an output from a light pipe, an output from an LED or laser excited phosphor, or an LED or laser. The apparatus of claim 1, wherein the output is any one of outputs from pumped up-converting materials.   The apparatus of claim 1, wherein the diagonal surface of the beam combiner comprises a spatially reflective portion to provide the semi-reflective surface.   The apparatus of claim 1, further comprising a gap or low index glue between each recycling light pipe and the beam combiner.   The apparatus of claim 1, wherein the beam combiner comprises a reflective polarizer to provide a single polarized output beam.   Each of the at least two light sources is a dual parabolic reflector (DPR) lamp coupled to an input end of a light pipe, and an output end of the light pipe is coupled to the input port of the recycling light pipe. The apparatus of claim 1.   The apparatus of claim 13, wherein the beam combiner comprises a reflective output surface for reflecting light and an output port for outputting light.   An apparatus comprising at least three light sources and at least three recycling light pipes, wherein the beam combiner combines the outputs of the recycling light pipes to provide the one output beam. Item 2. The apparatus according to Item 1. With dual paraboloid reflector (DPR) lamp as a light source, the reflective polarizer by recycled back to the DPR lamp reflects light polarized unused, increasing the brightness of the light output The apparatus according to claim 3. The light source is a white LED coupled to an input port of the recycling light pipe, and further includes a projection engine, a display panel, a projection lens, a relay lens, and a color wheel.
The projection engine is an optical component that functions as a waveguide;
The output of the recycling light pipe is coupled into the projection engine via the relay lens, the display panel, and the color wheel, so that a continuous color image for projection onto the screen by the projection lens is obtained. An LED projector incorporating the apparatus of claim 1, 2, 4, or 5 provided.   18. The LED projector according to claim 17, wherein the display panel is a digital mirror device (DMD) or a reflective liquid crystal display (LCOS) panel in which liquid crystal is formed on a silicon substrate. Further comprising a recycle reflector that recycles light by reflecting a portion of the light emitted by the LED back to the LED;
The LED projector according to claim 17, wherein the recycle reflector includes an output port for outputting light. The LED comprises a plurality of single color LEDs or multi-color LEDs,
The LED projector according to claim 19, wherein the recycling reflector increases light recycling efficiency by reflecting light from one LED onto another LED.   The LED projector according to claim 19, further comprising a condensing lens for aligning light emitted from the output port of the recycling reflector in the recycling light pipe. The light source is an RGB LED, and the projection engine, the display panel, the projection lens, the relay lens, the lenslet array, and a part of the light emitted from the RGB LED are reflected and returned to the RGB LED. And a recycle reflector for recycling
The projection engine is an optical component that functions as a waveguide;
The recycle reflector includes an output port for outputting light coupled to the lenslet array;
In order to time-multiplex light of three colors and provide a color image that the projection lens projects on a screen, the output of the recycling light pipe includes the relay lens, the display panel, and the lenslet array. An LED projector incorporating the apparatus of claim 1, 2, 4, or 5 coupled into the projection engine via The recycle reflector is a solid optical component with an output surface,
A portion of the output surface of the recycled reflector is coated with a reflective coating to provide a reflective surface, and the remaining portion of the output surface of the recycled reflector is transmissive to provide the output port. The LED projector according to claim 19, wherein   The light source includes a plurality of LEDs, a lens system, and a recycle reflector coupled to the lens system to reflect a portion of the light from each LED back to the plurality of LEDs and output the remaining portion of the light. The apparatus of claim 1, comprising:   25. The apparatus of claim 24, wherein the lens system is configured to output light to diffuse at a predetermined angle.   25. The light source of claim 24, wherein the light source comprises a diffuser positioned to receive the remainder of the light from the recycle reflector, or positioned to receive light output from the lens system. apparatus.   The apparatus of claim 5, wherein the BSC system comprises a diagonal interface that is partially reflective.   The apparatus of claim 5, further comprising a reflective polarizer at the output end of the recycling light pipe to provide a polarized light output.   6. The apparatus of claim 5, further comprising a plurality of BSC systems, a plurality of LEDs, and a triangular prism that has all its surfaces polished reflectively to promote TIR. An LED that provides input light as the light source , a projection engine, a projection lens, a display panel, a lenslet array, a color wheel, a relay lens, and a part of the input light to the lenslet array An LED projector comprising a recycle reflector for outputting and recycling the remaining portion of the input light back to the LED for recycling;
The projection engine is an optical component that functions as a waveguide;
Light as an output of the recycling light pipe via the lenslet array is coupled at an appropriate timing by the projection engine via the color wheel, the relay lens, and the display panel, and thereby the projection. 6. An LED projector incorporating an apparatus according to claim 1, 2, 4, or 5, wherein a continuous color image is provided that the lens projects onto a screen.   The LED projector according to claim 30, wherein the lenslet array is arranged in a circular or rectangular array.

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