MXPA06009105A - Reshaping light source modules and illumination systems using the same - Google Patents

Abstract

Light source modules are disclosed, which include an emitter (72, 72’, 72’’) having a light-emitting surface and a pyramid collector (12) mounted onto the emitter over the emitting surface. Also disclosed are illumination systems, including a plurality of light source modules, each light source module comprising an emitter having a light-emitting surface and a pyramid collector mounted onto the emitter over the emitting surface. The illumination systems further include an illumination target (17) and a system of optical elements (14, 18, 16, 19) disposed between the at least one light source module and the illumination target.

Description

MODULE OF CONFORMATION LIGHT SOURCES AND LIGHTING SYSTEM USED THEMSELVES FIELD OF THE INVENTION The present invention relates to shaping light modules and to lighting systems that use them, which can be used in projection systems. More specifically, the description relates to light source modules that include pyramidal collectors and lighting systems that use at least one such light source module. BACKGROUND OF THE INVENTION Lighting systems have a variety of applications, including projection screens, backlighting for liquid crystal displays (LCDs) and others. Projection systems typically include a light source, light optics, an image forming device, projection optics and a projection screen. The light optics collect light from a light source and direct it to one or more image forming devices in a predetermined manner. The image-forming device (s), controlled by means of an electronically conditioned and processed digital video signal, produces an image corresponding to the video signal. The projection optics then amplifies the image and projects it onto the projection screen. The sources of Ref .: 175071 white light, such as arc lamps, together with color wheels have been used and are still predominantly used as light sources for projection screen systems. However, recently, light-emitting diodes (LEDs) were introduced as an alternative. Some advantages of LED light sources include longer life time, greater efficiency and superior thermal characteristics. An example of an image forming device frequently used in digital light processing systems is a digital micromirror device (DMD). The main characteristic of a DMD is a rectangular arrangement of rotating micromirrors. The tilt of each mirror is controlled independently by the data loaded in the memory cell associated with each mirror, to orient the reflected light and spatially represent a pixel of video data to a pixel on a projection screen. The light reflected by a mirror in an ON state passes through the projection optics and is projected onto the screen to create a luminous field. On the other hand, the light reflected by a mirror in a OFF state loses the projection optics, which results in a dark field. A color image may also be produced using a DMD, for example, using color sequencing, or alternatively, using three DMDs, one for each primary color. Other examples of imaging devices include liquid crystal panels, such as liquid crystal silicon (LCOS) devices, which are typically rectangular. In the liquid crystal panels, the alignment of the liquid crystal material is incrementally controlled (pixel by pixel) according to the data corresponding to a video signal. Depending on the alignment of the liquid crystal material, the polarization of the incident light can be altered by the liquid crystal structure. Therefore, with the proper use of polarization beam polarizers or splitters, dark and light regions can be created, which corresponds to the input video data. The color images have been formed using liquid crystal panels similar to the DMD. The performance of optical systems, such as the lighting optics of a lighting system, can be characterized by a number of parameters, one of them being optical efficiency. The optical efficiency, e, can be calculated using the following formula: £ • = A * O = p * A * sin2? = p * A * NA 2 where O is the solid emission or acceptance angle (in steradians); A is the area of the receiver or emitter,? is the emission or acceptance angle, and NA is the numerical aperture. If the optical efficiency of a certain element of an optical system is less than the optical efficiency of an upstream optical element, the mismatch can result in loss of light, which reduces the efficiency of the optical system. Therefore the performance of an optical system is usually limited by the element that has the smallest optical efficiency. Techniques typically employed to reduce the degradation of optical efficiency in an optical system include increasing the efficiency of the system (lm / w), reducing the size of the source, decreasing the solid angle of the beam and preventing the introduction of additional aperture diaphragms. . The traditional optics used in lighting systems have included several configurations, but their off-axis performance has been satisfactory only within narrowly adjusted ranges. In addition, optics in traditional lighting systems have shown insufficient collection characteristics. In particular, if a significant part of a light source output emerges at angles that are far from the optical axis, which is the case for most LEDs, conventional lighting systems fail to capture a substantial part of said light. . In addition, although some traditional reflective collimators have acceptable picking characteristics, for example, elliptical and parabolic reflectors, such reflectors are typically characterized by a rotationally symmetric displacement. Such displacement generally results in rounding of the resulting image, as well as in a lack of global correspondence between a point in the light source and a point in the other objective plane, thus causing loss of order and degradation of optical efficiency. These and other drawbacks resulted in complicated designs of optical elements and systems, which included, for example, the use of complicated aspherical surfaces and complex combinations of numerous elements. BRIEF DESCRIPTION OF THE INVENTION The present description is directed to a light source module, which includes an emitter having a light emitting surface and a pyramidal collector mounted on the emitter on the emitting surface. The proximal end of the pyramidal collector is oriented towards the emitting surface, while the distal end of the pyramidal collector is oriented away from the emitting surface. In the appropriate exemplary embodiments of the present disclosure, the proximal end of the pyramidal collector is in contact with the light emitting surface. The dimensions and shape of the proximal end of the pyramidal collector may be approximately the same as the dimensions and shape of the emitting surface. For example, the proximal and distal ends may both have a generally square shape or the proximal end may have a generally square shape while the distal end has a generally rectangular shape. In some exemplary embodiments, the proximal end of the pyramidal collector is mounted around the emitting surface. Also, in some embodiments, the distal end of the pyramidal collector has a generally pincushion configuration. In accordance with the present disclosure, the pyramidal collector can be configured to collect at least about 70 percent of the light emitted by the emitter. The distance between the proximal and distal ends of the pyramidal collectors constructed in accordance with some example embodiments of the present disclosure is typically about 3 to 5 times greater than a larger diagonal of the distal end of the collector. In some embodiments, the pyramidal collector has tapering sides from about 2 to about 6 degrees from the distal end of the distal to proximal end. In some example modalities, the pyramidal collector has sides that taper no more than about 10 degrees from the distal end to the proximal end. The light source modules constructed in accordance with the present disclosure may further include a rectangular straight tube section disposed adjacent the distal end of the pyramidal collector. Where both the straight tube section and the dome potion are included, the straight tube portion may be disposed between the dome portion and the pyramidal collector. Optionally, the pyramidal collector includes a flange with a generally disc shape disposed between the dome portion and the pyramidal collector. The present disclosure is also directed to lighting systems that include two or more light source modules, a lighting objective and a system of optical elements disposed between the at least one light source module and the lighting objective. Each light source module includes an emitter having a light emitting surface and a pyramidal collector mounted on the emitter on the emitting surface. Each pyramidal collector has a proximal end facing the emitting surface and a distal end oriented away from the emitting surface. The light source modules can be arranged in an array within an aperture that is not radially symmetric. Wherein the illumination target is an image forming device arranged to be illuminated at an angle and has a plurality of rotating mirrors about a pivot axis, the aperture that is not radially symmetric has a long dimension and a short dimension and it is oriented in such a way that the long dimension is aligned with the pivot axis of the mirrors of the image forming device. Optionally, the light source modules and the optical element system can be configured to form a plurality of channels directed substantially toward the illumination target. In such exemplary lighting systems, the light source modules may be disposed tangentially with respect to and along a spherical surface. In accordance with some exemplary embodiments of the present disclosure, the proximal and distal ends of each pyramidal collector can both have a generally square shape while the distal end of each collector has a generally rectangular shape. The optical element system can be configured to reflect the distal end of each pyramidal collector on the illumination target. In such exemplary lighting systems, the emitting images can substantially overlap to form a lighting spot, which can substantially fill or overfill the lighting objective. Alternatively, the images of the light emitting surfaces may be closely packed or they may overlap to form a lighting spot. The shape of at least one of the distal ends of the pyramidal collectors may substantially coincide with the shape of the illumination objective. The lighting objective, for example, can be substantially square or substantially rectangular. These and other aspects of the light source modules and the lighting systems of the subject invention will be readily apparent to those of ordinary skill in the art from the following detailed description along with the drawings. BRIEF DESCRIPTION OF THE FIGURES For those with experience in the art to which the subject invention is directed will more readily understand how to make and use the subject invention, the embodiments thereof will be described in detail below with reference to the figures, wherein : Figure 1 is a schematic cross-sectional view of a lighting system constructed in accordance with an exemplary embodiment of the present description; Figure 2A is a schematic side view of a light source module constructed in accordance with an exemplary embodiment of the present disclosure; Figure 2B is a schematic front view of the exemplary light source module shown in Figure 2A; Figure 2C is a schematic top view of the exemplary light source module shown in Figures 2A and 2B; Figure 3A is a schematic side view of a light source module constructed in accordance with another exemplary embodiment of the present disclosure; Figure 3B is a schematic front view of the exemplary light source module shown in Figure 3A; Figure 3C is a schematic top view of the exemplary light source module shown in Figures 3A and 3B; Fig. 4 represents a ray tracing schematically illustrating the collection of light in a light source module similar to the example light source modules depicted and described with reference to Figs. 3A-3C; Fig. 5 is a schematic representation of a test configuration for determining the shape of the existing light source modules of illumination in accordance with exemplary embodiments of the present disclosure; Figure 6 represents the output irradiation of a light source module shown and described with reference to Figures 3A-3C, when tested using the system of Figure 5; Figure 7 is a schematic view of a light source module constructed in accordance with another exemplary embodiment of the present disclosure, illustrating a pincushion configuration; Figure 8 represents a ray tracing that schematically illustrates light collection in a light source module similar to the example light source modules depicted and described with reference to "Figures 3A-3C and 7; presents the output irradiation of a light source module shown and described with reference to Figures 3A-3C and 7, when tested using the system of Figure 5, Figure 10A is a schematic side view of a source module of example light constructed in accordance with another embodiment of the present disclosure: Figure 10B is a schematic front view of the light source module shown in Figure 10A, Figure 10C is a schematic top view of the light source module of Figure 10A; example shown in Figures 10A and 10B, Figure 11 depicts a test configuration and a ray tracing that schematically illustrates the collection of light in a similar light source module to the one depicted and described with reference to Figures 10A-lOC- Figure 12 depicts the output irradiation of a light source module shown and described with reference to Figures 10A-10C, when tested using the system of Figure 11; Figure 13 is a schematic representation of an exemplary configuration of a set of light source modules constructed in accordance with exemplary embodiments of the present disclosure, illustrating the placement of the set of light source modules to substantially approximate a opening that is not radially symmetric; and Figure 14 is a schematic cross-sectional view of a lighting system constructed in accordance with another exemplary embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION Referring now to the figures, in which like reference numerals designate similar elements, FIG. 1 schematically shows an example embodiment of lighting systems of the present description, which can be used for projection applications. The lighting system 10 shown in Figure 1 includes a set of light module 12, illustrated by the light source modules 72, 72 and 72", and a system of optical elements 15. One or more light modules. Light sources may include an LED light source Those of ordinary skill in the art will appreciate that as LEDs are developed and perfected with greater efficiency and output, said LEDs will advantageously be used in exemplary embodiments of the present disclosure, since they are preferred. LED with a high maximum output Alternatively, organic light emitting diodes (OLED) can be used, vertical cavity surface light emitting lasers (VCSEL) or other suitable light emitting devices. The light source modules 12 can be configured as an array, such as a linear, Cartesian or hexagonal array. The light source modules, such as 72, 72 '. 72", can be mounted on one or more substrates, together or individually, in such a way that the heat generated by the light source modules can be quickly dissipated by the material of the substrates or by other means. Examples of suitable substrates for mounting the light source modules include printed circuit boards, such as metal core printed circuit boards, flexible circuits, such as polyimide film with traces of copper, ceramic substrates, and others. Those of ordinary skill in the art will appreciate that many configurations of the set of light source modules 12 and individual light source modules, such as 72, 72Y 72", are within the scope of the present disclosure. number and type of light source modules may vary depending on the application, desired system configuration, system dimensions, and output brightness of the system.In the exemplary embodiments illustrated in Figure 1, the optical element system 15 includes a set of lenses 14, exemplified by the lenses 74, 74A 74", a capacitor 18, a field lens 16 and other optical elements 19, such as a TIR prism. Similar to the number of light source modules, the number of lenses in the assembly 14 may vary depending on the application, the desired system configuration and the desired system dimensions. In the appropriate embodiments of the present disclosure, each light source module has an optical element or elements associated therewith in order to facilitate the collection of light and to achieve the desired image rendering characteristics. A light source module and the optics associated therewith will be collectively referred to herein as "channel". For example, in the example embodiments illustrated in Figure 1, the lens 74 is associated with the light source module 72, the lens 74 'is associated with the light source module 72 and the lens 74"is associated with the light source module 72. the light source module 72". The lenses of the assembly 14 are preferably plano-convex, and the convex surface can be made aspherical in order to reduce aberrations and to avoid the resulting loss of light. However, those skilled in the art will readily appreciate that the overall shape and size of the lenses may vary depending on the specific application, the system configuration, the size of the system and cost considerations. The material of the lenses is preferably acrylic, but polycarbonate, polystyrene, glass or any other suitable material can also be used. In general, materials with higher refractive indexes are preferred, but finally the choice will be made depending on factors that are important for a particular application, such as cost, moldability, ease of matching the refractive index with glues or epoxies, etc. In the appropriate embodiments of the present disclosure, the lens assembly 14 can all be omitted from the system of optical elements 15, such that the light source modules would share the same optics. In some exemplary embodiments, the optical element system may include the capacitor 18, which may be or may include a plano-convex lens. Alternatively, the capacitor may be or may include a meniscus lens for the purpose of reducing aberrations, or any other type of lens or lenses depending on the desired characteristics of the exit light. The optical element system 15 can include other components in addition to or instead of the capacitor 18, since it may be useful for a particular application, for example it may include dichroic mirrors to separate or combine light beams of different colors, or other separators or combiners. With further reference to Figure 1, the nature of the lighting objective 17 will vary depending on the specific application. For example, the lighting objective 17 can be an entrance to a light tunnel. Light tunnels suitable for use with the appropriate exemplary embodiments of the present disclosure are described, for example, in U.S. Patent Nos. 5,625,738 and 6,332,688, the disclosures of which are incorporated herein by reference to the extent to which they are not inconsistent with the present description. A light tunnel would serve to homogenize the output of the light emitting modules, such as 72, 72 ', 72", and can be a mirror tunnel, normally rectangular, solid or hollow, or an elongated tunnel composed of a bar solid glass that depends on the total internal reflection to transfer light through it Those of ordinary skill in the art will appreciate that numerous combinations of shapes are possible for the entrance and exit ends of the light tunnels. , the lighting objective 17 can be an image forming device, for example, a DMD or LCOS.

Figures 2A-2C schematically show an exemplary configuration of a light source module for use in the appropriate embodiments of the present disclosure.

In particular, Figures 2A-2C show a light source module 172, with Figure 2A being a side view, Figure 2B is a front view, and Figure 2C is a top view. The light source module 172 includes an emitter 722 having a emitting surface 724 and a short pyramidal collector 727 mounted on the emitter on the emitting surface 724. The short pyramidal collector 727 is preferably a substantially optically transparent article, for example made of acrylic, polycarbonate or other suitable material, whose sides operate as simple reflectors for light emanating from one or more emitting surfaces at angles that are large enough to result in a total internal reflection of such light within the pyramidal collector. Those skilled in the art will readily appreciate that the light collection efficiency will be improved for pyramidal collectors made of materials with higher refractive indexes. The emitting surface 724 may be or may include a surface or emitting surfaces of an LED, a phosphor layer, or any other emitter material. Those of ordinary skill in the art will understand that the term "emitting surface" may be used to refer to any light emitting surface of a light source module, such as any surface portion of a light emitting semiconductor layer or chip encapsulated within a substantially optically transparent material. If the emitting surface 724 is an emitting surface of an LED (which may include several emitting strips) the pyramidal collector 727 is preferably placed on the emitting surface (s) and joined to the LED by means of a suitable substantially and optically transparent binder material or It molds directly on it, in such a way that it is in contact with and covers the entire emitting surface or the multiple emitting surfaces of the LED. The minimization or removal of an air space between the emitting surface of an LED and the pyramidal collector typically improves the collection efficiency. The refractive index of the binder material should be selected depending on the refractive index of the pyramidal collector material. If the refractive index of the binder material is greater than the refractive index of the pyramidal collector material, a significant part of the emitted light may be lost due to reflections at its interface. Therefore, preferably, the refractive index of the binder material substantially matches or is slightly less than the refractive index of the pyramidal collector, in order to facilitate more efficient light collection. As shown in Figures 2A-2C, the pyramidal collector 7627 of this exemplary embodiment has a generally square proximal end 725 facing the emitting surface 724 and a generally rectangular distal end 729 oriented away from the emitting surface 724. For a emitter with a generally square external shape of the emitting surface, with a side of about 1 mm, such as the active surface of an InGaN LED, an example of suitable dimensions of the pyramidal collector 727 includes a generally square proximal end 727 with the side of about 1 mm, a generally rectangular distal end 729 of about 4.3 mm by about 2.4 mm, and the height of the pyramidal collector (the distance between the proximal and distal ends) of about 5 to about 15 mm. The shape of the distal end, including the aspect ratio, preferably coincides with the shape of the illumination objective 17, shown in Figure 1. At least a portion of the incident light on the sides of the pyramidal collector 727 can be internally reflected in full or it can be reflected internally by means of a reflector 723 provided on the sides of the pyramidal collector 727. Preferably, the reflector 723 surrounds at least a portion of the pyramidal collector 727. The reflector 723 may or may not extend over the entire length of the pyramidal collector 727. For example, the reflectors 723 may be provided on the sides near the emitting surface 724, as it is shown in Figures 2A-2C, where there is a great possibility that light is incident at an angle greater than the critical angle of the material used to make the element. In such exemplary embodiments, the sides of the pyramidal collector 727 may depend on the total internal reflection closest to the distal end 729 of the pyramidal collector 727, since the chance of light being incident at an angle greater than the critical angle may be reduced. . The reflectors 723 can use reflective coatings or can be mounted to a suitable part of the emitter 722. In some exemplary embodiments, the reflectors 723 can be silvered or aluminized mirrors. The reflector 723 can be formed from a molded part, or it can be made as a thin metal surface that is shaped to the desired shape. Optionally, the light source module 172 may include a rectangular tube section 730 added together with the pyramidal collector 727. The tube section 730 may be molded from acrylic, polycarbonate or other suitable plastic material. The cross-sectional dimensions of the tube 730 preferably coincide substantially with the dimensions of the distal end 729 of the pyramidal collector 727, while the suitable length of the tube section 730 is approximately 1 to approximately 2 mm, or in some exemplary embodiments even up to half the total length of the light source module 172. Generally, the length of the tube section would be selected based on the desired degree of homogeneity of the exit illumination, the dimensions of the pyramidal collector and other factors, such as the desired total length of the light source module. For example, in an exemplary embodiment that includes tube section 730, the generally square proximal end 725 of pyramidal manifold 727 is approximately 1.0 x 1.0 mm in size to match a similarly sized emitting surface, the distal end 729 is generally rectangular with the size of about 4.3 by about 2.5 ram, the distance between the proximal and distal ends of the pyramidal collector 727 is about 5 mm, and the length of the rectangular tube section 730 is about 2 mm. Figures 3A-3C schematically show another exemplary light source module configuration suitable for use in the appropriate embodiments of the present disclosure. The light source module 272 includes an emitter 722 having a emitting surface 724 and a pyramidal collector 727 mounted on the emitter 722 on the emitting surface 72. If the emitting surface 724 is an emitting surface of an LED (which may include several emitting strips) the pyramidal collector 727 is preferably placed on the emitting surface or surfaces and joined to the emitter 722 by means of a suitable substantially transparent and optically transparent binder material. or molded directly thereon, in such a manner as to cover the entire emitting surface 724 or the multiple emitting surfaces of the emitter 722. Similarly to the light source module 172 shown in FIGS. 2A-2C, the pyramidal collector 727 of the source module Example light has a generally square proximal end 725 facing the emitting surface 724 and a generally rectangular distal end 729 oriented away from the emitting surface 724. Optionally, the light source module 272 may also include a straight rectangular tube section 730 added to the pyramidal collector 727. The dimensions of the light source module 272 are typically approximately the same as the example dimensions of the light source modules described with reference to Figures 2A-2C. In some exemplary embodiments, the pyramidal collector 727 may include a reflector 723, as described with reference to FIGS. 2A-2C. In addition, the example light source module shown in Figures 3A-3C includes a dome portion 750, convex surface cure, for example, is a generally spherical surface with the radius of curvature of about 4 to about 5 mm. The portion of the dome 750 helps compress the output of the preceding structures in a narrower range of angles. Depending on whether the light source module includes the rectangular tube section 730 after the pyramidal collector 727, the dome portion 750 can be attached to the distal end 729 of the pyramidal collector 727 or to the rectangular tube section 730. The dome portion may be truncated or substantially approximate to the dimensions of the element to which it is attached, or excess material may be left beyond the collection path to form a mounting flange 752. The passive elements of the light source modules, such as the pyramidal collector with the dome, the pyramidal collector with the straight tube and the dome, or the pyramidal collector with the straight tube, can be molded as a unit or they can be manufactured separately and subsequently assembled together. Figure 4 represents a ray tracing that schematically illustrates the collection of light in a light source module similar to that depicted and described with reference to Figures 3A-3C. Here, light is collected from an InGaN LED with a generally square emitting surface. Generally, in the appropriate embodiments of the present description, the picking efficiency of the near lambertian emitting surface of an LED will be relatively high, because a large part of the light is reflected by means of total internal reflection and maintained in the pyramidal collector. However, a small portion of light will evade collection, including rays that are nearly perpendicular to the optical axis "and some rays that are reflected back to the emitter, as a result, as much as approximately 70%, or in some embodiments approximately 82% or more, the output of the emitter is collected in the pyramidal collector 727 and associated elements, such as the tube section 730 and the dome portion 750, and the result is illumination with a substantially uniform rectangular cross-section, with a relatively narrow angular extent and relatively high collection efficiency Figure 5 represents a computer simulated test configuration for determining the form of illumination exiting a light source module 72. The test configuration includes image forming optics 16 to focus the illumination coming out of the light source module 72 on a detect Array 84 arranged in the plane of the lighting objective. Figure 6 represents the simulated output image produced by the detector 84, showing the output irradiation of the light source module 272 when tested using the system of Figure 5. The light source modules can be combined and their outputs can be overlap to increase the output illuminance with a commensurate increase in an angular extent. Although the example configurations described with reference to Figures 2A-2C and 3A-3C work well for most applications and may be preferred in view of various considerations, such as low cost of some modalities, it can be seen from the Figure 6, that although the simulated image of the light source module 272 is generally rectangular, the image optic 16 depends on the image with some distortion in the barrel. Such distortion can cause the illumination spot to fill underneath the corners of a rectangular lighting objective. To counteract the distortion in skipjack, the pyramidal collector with generally flat walls, such as the pyramidal collector 172 or 272 (Figures 2A-3C), can be shaped to obtain a pincushion shape, such as the shape shown in Figure 7. Figure 7 schematically illustrates a collector pyramidal 737 having a generally square proximal end 735 and a distal pincushion end 739. The sides 737a, 737b, 737c and 737d of the pyramidal collector 737 are shaped as cylindrical or generally conical surfaces. The pyramidal collector 737 can be molded from acrylic, polycarbonate or any other suitable material, in the manner shown in Figure 7. Alternatively, appropriately shaped cuts can be made in a pyramidal collector initially fabricated with straight walls. The distal end 739 of the pyramidal collector 737, for example, has the aspect ratio of approximately 16: 9. Other example dimensions of the pyramidal collector include approximately 1.0 x 1.0 mm of the proximal end square, approximately 4.3 x 2.4 of the distal end, and approximately 4 mm of distance between the proximal and distal ends. Exemplary parameters of the substantially cylindrical surfaces include a radius of about 3 mm on the longer sides and a radius of about 1.1 mm on the shorter sides. Substantially conical surfaces with approximately the same radii can also be used. The pyramidal collector 737 is mounted on the emitter on its emitting surface (s). For example, the pyramidal collector can be molded or bonded on an emitting surface of an LED by means of an adhesive, substantially and optically transparent, epoxy or any other suitable material with a suitably chosen refractive index. As shown schematically in Figure 8, the example light source module 372, which includes the pyramidal collector 737 for collecting light from the emitter 722, also includes a dome portion 760, whose convex surface, for example, is a a generally spherical surface that has a radius of approximately 5 mm. The dome portion helps compress the output of the preceding structures in a narrower range of angles. The dome portion 760 may be attached to the distal end 739 of the pyramidal manifold 737 or integrally molded therewith, and may be truncated or substantially approximate to the dimensions of the element to which it is attached.

Alternatively, excess material can be left beyond the collection path to form a mounting flange 762. Preferably the passive elements of the light source modules, such as the pyramidal collector with the dome, are molded as a unit to avoid need for optical coupling. Figure 8 also represents a ray tracing that schematically illustrates the collection of light in a light source module similar to that depicted and described with reference to Figures 3A-3C. Here, light is collected from an InGaN LED with a generally square emitting surface. As mentioned above, in the appropriate embodiments of the present description, the picking efficiency of the near lambertian emitting surface of an LED will be relatively high, because a large part of the light emitted by the emitter is reflected by means of the total internal reflection and maintained in the pyramidal collector. A small portion of light evades collection, including rays that are nearly perpendicular to the optical axis and some rays that are reflected back to the emitter. As a result, as much as about 78% of the output of the emitter is collected in the pyramidal collector 737 and the 760 dome, and they fall in a specific area. The resulting illumination is a cross section of approximately rectangular shape substantially uniform with. a relatively narrow angle extension and a relatively high collection efficiency. Figure 9 depicts the simulated output image produced by the detector 84 when the light source module 372 is tested using the simulated test configuration of Figure 5. The light source modules can be combined and their outputs can be superimposed to increase the output illuminance with a commensurate increase in an angular extent. For example, five to ten light source modules, such as the light source module 737, can be combined to overfill the allowable optical efficiency for a typical micro-screen projection system. Figures 10A-10C schematically show another exemplary configuration of a light source module suitable for use in the appropriate embodiments of the present disclosure. In particular, Figures 10A-10C show a light source module 182, Figure 10A being a side view, Figure 10B being a front view, and Figure 10C being a top view. The light source module 182 includes an emitter 822 having a emitting surface 824 and a pyramidal collector 827 mounted on the emitter 822 on the emitting surface 824. The pyramidal collector 827 is preferably a substantially optically transparent article, for example made from acrylic, polycarbonate, glass or other suitable material, whose sides operate as simple reflectors for the light emanating from the emitting surfaces or at angles that are large enough to result in a total internal reflection of said light in the pyramidal collector. As in other exemplary embodiments of the present disclosure, the emitting surface 824 may be or may include a surface or emitting surfaces of an LED, a phosphor layer, or any other emitter material. If the emitting surface 824 is a surface emitting an LED (which includes several emission strips) the pyramidal collector 827 is preferably disposed on the emitting surface or surfaces and is attached to the emitter 822 by means of a binder material or molded directly thereon, such that it covers the entire emitting surface 824 or the multiple emitting surfaces 822. As explained above , the refractive index of the binder material should be selected depending on the refractive index of the pyramidal collector material. As shown in Figures 10A-10C, the pyramidal collector 827 of the present exemplary embodiment has a generally square proximal end 825 facing the emitting surface 824 and a generally rectangular distal end 829 oriented away from the emitting surface 824. For an emitter with the generally square external shape of the emitting surface, with a side of about 1 mm, such as the active surface of an InGaN LED, the preferred dimensions of the pyramidal collector 827 include a generally square proximal end 825 with the side of about 1 mm, a generally rectangular distal end 829 of about 3.4 mm by approximately 2 mm, and the height of the pyramidal collector (the distance between the proximal and distal ends) of approximately 12 mm. The shape of the distal end, including the aspect ratio, preferably coincides with the shape of the aspect ratio of the lighting objective 17, shown in Figure 1. Optionally, the light source module, may include a shaped flange. disc 830 added on the pyramidal collector 827. The flange 830 can be molded of acrylic or polycarbonate or any other optical plastic material.

In some example modalities that include the flange 830, the outer diameter of the flange is approximately 12 mm and its thickness is approximately 1.5 mm. Additionally, the light source module 182 includes a dome portion 850, whose convex surface, for example, is spherical with the radius of about 5 mm and the outer diameter of about 10 mm. Depending on whether the light source module includes the flange 830, the dome portion 850 may be attached to the distal end 829 of the pyramidal collector 827 or to the flange 830. The dome portion may be truncated or approximate to the dimensions of the element to which it is attached. is attached, or excess material can be left beyond the collection path to form a mounting flange 852. Preferably, the passive elements of the light source modules, such as the pyramidal collector with the dome or the pyramidal collector with The flange and dome are molded as a unit, so there is no need for optical coupling. Figure 11 depicts a ray tracing that schematically illustrates the collection of light in a light source module similar to that depicted and described with reference to Figures 10A-10C. Here, light is collected from an InGaN LED with a generally square emitting surface. As mentioned above, in the appropriate embodiments of the present description, the picking efficiency of the near lambertian emitting surface of an LED will be relatively high, because a large part of the light is reflected by means of total internal reflection and maintained in the pyramidal collector. A small portion of light evades collection, including rays that are nearly perpendicular to the optical axis and some rays that are reflected back to the emitter. As a result, as much as about 80% of the output of the emitter is collected in the pyramidal collector 827. The resulting illumination has a substantially uniform rectangular cross-section with a relatively narrow angular extent and a relatively high collection efficiency. Fig. 12 represents the simulated output image produced by the detector 94 (see Fig. 11), when the light source module 182 is tested using the simulated test configuration of Fig. 11, using a focus lens 26. Focus lens 26 transmits light emanating from light source module 182 on detector 94 arranged in the objective plane of illumination. In some embodiments of the present disclosure, the external dimensions and the shape of the distal end, for example 725, 735 or 835, preferably substantially coincide with the dimensions and shape of the emitter and fit substantially around the emitting surface or surfaces of the emitter. However, in some embodiments, the dimensions of the proximal ends of the pyramidal collectors according to the present disclosure may be larger and have different shapes of the emitting surfaces. For example, the proximal end may have a generally circular shape that fits substantially around a generally square emitting surface. The distal end, such as 729, 739 or 829, is preferably a larger rectangle, for example with - the aspect ratio of approximately 16: 9 (which is particularly useful for HDTV applications), 4: 3 or other ratio Aspect. Alternatively, the distal end may have a generally square shape. In other exemplary embodiments, the distal end may have a generally elliptical shape. For most of the applications contemplated by the present disclosure, the distance between the proximal and distal ends of the pyramidal collectors constructed in accordance with the present disclosure would be about 3 to 5 times longer than a longer diagonal of their distal end., and the sides of the pyramidal collector would be tapered at no more than 10 degrees from the distal and proximal ends, more commonly from about 2 to about 6 degrees. Also within the scope of the present description are larger angles, but such larger angles would typically require a more careful balance of the desired degree of light that is mixed in the pyramidal collector against the total length of the collector. Those of ordinary skill in the art will readily appreciate a variety of other dimensions and suitable configurations of the pyramidal collectors are within the scope of the present disclosure, depending on the dimensions, shape and uniformity of the emitting surface, the dimensions and shape of the collection optics and other relevant parameters of the system. For example, in some embodiments, the taper angle may be selected depending on the total desired collector length, the degree of light mixing in the collector, the collection efficiency and other relevant factors. The use of a pyramidal collector, such as pyramidal collectors 727, 737 or 827, is particularly advantageous where the emitting surface is an emitting surface of an LED that does not appear sufficiently uniform and / or where a square emitting surface needs to conform, for example to match a rectangular lighting objective. In addition, the pyramidal collectors of the present invention can collect a relatively large portion of the emitter output and redirect it in such a way that it would exit the pyramidal collector in a smaller range of angles with respect to the optical axis and therefore may be easier to collect by the optical elements downstream. In addition, the far field output of the example light source modules including pyramidal collectors can form a pattern that can be tightly packed (with some overlap, if desired) with others to form a combined illumination spot, which is particularly useful in projection and backlight applications. Therefore, the advantages of using the exemplary embodiments of the present disclosure include improved output lighting uniformity, ability to shape the emitting surface from any form of a set of shapes to a desired shape, while decreasing the range of exit angles without degradation of optical efficiency, and maintaining a relatively high collection efficiency. In accordance with another aspect of the present disclosure, an example configuration of the set of light source modules is shown in FIG. 13, which shows a theoretical circular input pupil 2 of a lighting system and an aperture that is not radially symmetrical 4, representing the entrance pupil formed by the appropriate placement of the set of light source modules 12 '. This and similar configurations are particularly advantageous in projection systems that use one or more DMDs illuminated at an angle and without a light tunnel (described below) interposing between the light source and the image forming device. Generally, in such systems there is a strong dependence between the angle of illumination and the amount of light scattered in a projection pupil by reflection of the mirror box, below the DMD mirrors in OFF states, and of the mirrors in flat states or in transition. The increase in the angle of illumination increases the contrast, but also causes a misalignment of the illumination pupil with respect to the projection pupil, introducing a degradation, if the numerical aperture of the projection optics does not increase correspondingly. However, if the aperture of the projection optics is increased to prevent degradation, it can collect more plane or transition state reflections (neither ON or OFF) and diffuse light from around the DMD and passes it to the screen, potentially overcoming the initial attempt to improve the contrast. In traditional lighting systems using arc lamps, this problem was addressed by placing a truncated aperture diaphragm in the illumination pupil to block at least a portion of the flat state reflections that overlap with the state reflections ON. However, recently, it has been shown that the contrast of the DMD projection systems can be improved with asymmetric aperture diaphragms. U.S. Patent No. 5,442,414, the disclosure of which is incorporated herein by reference to the extent that it is not inconsistent with the present disclosure, discloses asymmetric openings that enhance contrast, with long and short dimensions, the long dimension aligning with the axis of pivot of the mirrors. Therefore, in the appropriate exemplary embodiments of the present disclosure, the configuration of the set of light source modules 12 'may be selected such that the light source modules are disposed substantially within the area of the pupil having the highest contrast, illustrated as the aperture that is not radially symmetric 4, thereby conserving the lighting energy and reducing the number of the used light source modules. The configuration of the set of optical elements 13, associated with the light source modules, can be selected correspondingly, and preferably, it will follow the configuration of the set of the light source modules 12 ', in such a way that the latter would have the general shape substantially close to an aperture that is not radially symmetrical, as illustrated in Figure 13. Other configurations of the light source module assemblies and the optical element assemblies, for example the lens assembly 14 shown in Figure 1 , are also within the scope of the present disclosure, such arrangements have a generally rectangular or square shape, depending on the specific application and other considerations, such as the shape and size of the system, as well as its cost. With further reference to Figures 1, 2A-2C, 3A-3C and 10A-10C, in some exemplary embodiments of the present disclosure, the system of optical elements 15 represents the image of one or more of the distal ends of the collectors. pyramidal, for example, the distal end 729, 739 or 829, on the illumination target 17. Such an imaging approach provides improved energy transfer from the light source modules to the illumination objective. The representation of the image of a pyramidal collector allows the emitting surface to retain its original shape, such as a square or a set of commercially available typical LED strips. The pyramidal collector will effectively create a rectangular pattern of light that can then be displayed on a rectangular lighting target without the need to homogenize and shape it by means of additional optics. In addition, this configuration helps conserve optical efficiency, because the angles of illumination are reduced proportionally with the increase of the area from the proximal end to the distal of the pyramidal collector. If the emitting surface is represented on an entrance to a light tunnel, an accurate representation would not be necessary. On the other hand, in the modalities where light tunnels are not used, a more accurate representation of images may be desired. Furthermore, such modalities, if used, for example, in projection systems using one or more DMDs, would be beneficial in arranging the light source modules to substantially approximate the shape of the asymmetric contrast enhancement aperture, illustrated in FIG. Figure 13. With further reference to Figure 1, the system of optical elements 15 can be designed and configured to appropriately amplify the images of the distal end of the pyramidal collectors. The performance of a typical projection screen would normally benefit from, or in some cases would still require, a certain amount of overfill of the illumination objective by the illumination spot, which in these example modalities would be formed by superimposed images of one or more of the distal ends of the pyramidal collectors. For example, for an image display device of approximately 20.0 x 12.0 mm, the illumination spot may be approximately 10% larger on each axis, or approximately 22.0 x 13.4 mm. In some embodiments, it is desirable to cause the amount to overfill substantially equally on all sides, for example, to accommodate mechanical misalignments. In such cases, one or more of the distal ends of the pyramidal collectors can be made slightly different in aspect ratio of the illumination target, in order to produce an image of the desired shape. Also, when desired, illumination of emitters having "different" colors, such as red, green and blue, or other primary colors, may be combined or superimposed with dichroic combiners as would be known to those of ordinary skill in the art. Another group of exemplary embodiments of the lighting systems of the present disclosure is illustrated in Figure 14. In such exemplary embodiments, the configurations of the optical element systems are such that the capacitor 18 used in the illustrated embodiments may be omitted. in Figure 1. Instead, the modalities illustrated in Figure 14 use one or more focused channels in a more individual and directed manner, including one or more optical elements associated with each light source module, such as one or more lenses, which direct and focus a portion of the emission of one or more modules of light sources on a lighting objective, preferent in such a way that they overlap the lighting target to form a lighting spot. For example, Figure 14 is a schematic representation of a lighting system 20 including a set of light source modules 22, such as light source modules 72, 72 ', 72", and a system of optical elements. 25. The set of light source modules 22 is configured in such a way that a portion of the emission of each light source module points substantially towards the lighting target 27. This can be achieved, for example by arranging the set of modules of light source. light sources 22, such as 72, 72 ', 72", tangentially with and along a spherical surface centered on the illumination target. With further reference to Figure 14, in some exemplary embodiments of the present disclosure, the system of optical elements 25, exemplified by the lenses 75, 75 ', 75", etc., may be configured to represent the image of one or more distal ends of the pyramidal collectors on the illumination objective 27. As explained above, the nature of the illumination objective 27 will vary depending on the specific application. Those of ordinary skill in the art will readily appreciate that the number and type of modules of Light sources and the optical elements associated with each light source module, thus forming individual directed channels, may vary depending on the application, the desired system configuration and the dimensions of the system.

The exemplary embodiments of the present disclosure, wherein the light from one or more light source modules is focused on the same lighting objective pointing towards the individual channels in the objective may employ fewer parts, may have lower cost, may be more efficient, and in some modes can result in brighter outputs than the modes using shared capacitors. However, exemplary embodiments using capacitors allow more flexibility, since a capacitor can be used to adjust the beam angle of the output light, the back focal length and the amplification. In addition, in the exemplary embodiments illustrated in Figure 14, the light source modules are non-coplanar, which is a disadvantage for the mounting of printed circuit boards. On the other hand, if the light source modules are mounted on the same substrate, such as the printed circuit board itself, the associated optical elements arranged around the periphery of the system can be directed or tilted, for example as described in FIG. US application entitled "Illumination System", Proxy Control Number 59373US002, filed together with the present and incorporated herein by reference to the extent that it is not inconsistent with the present disclosure. The inclination of the optical elements can result in a lower illuminance compared, for example, with the system in which the light source modules point towards the center of a sphere and are mounted tangentially thereto. Each of the exemplary embodiments described herein can be particularly advantageous for a specific application. A specific modality can be selected for a particular application based on its optical performance, such as lighting, manufacturing facility and low cost (molded plastic components), the existing and desired degree of emitting surface uniformity, the amount of reduction of exit angles, and the susceptibility to modules overlap. The performance of the lighting system is also usually improved by increasing the number of light source modules, as well as by the use of the directed configuration as compared to the example modes using shared capacitors. The approach of the present description simplifies the design of lighting systems for a variety of specific applications and allows many different configurations of light source modules, image rendering optics and lighting objectives. Exemplary embodiments of the present disclosure are capable of collecting light from Lambertian type emitters, such as LEDs, more effectively than traditional systems while preserving optical efficiency. Therefore, more light can be transmitted to the lighting objective resulting in better overall efficiency. Furthermore, the present description allows the creation of lighting systems that use fewer components, which are compact, versatile, and easier and less expensive to manufacture. Although the lighting systems of the present disclosure have been described with reference to specific exemplary embodiments, those of ordinary skill in the art will readily appreciate that changes and modifications can be made thereto without departing from the spirit and scope of the invention. present description. For example, the shape and dimensions of the light source modules may vary. In particular, the light source modules may have additional sections included therein as may be desired for a particular application or for assembly convenience. On the other hand, the dimensions and configurations of the optical element systems that are used in various embodiments of the present description may vary depending on the specific application and the nature and dimensions of the lighting objective. further, the exemplary embodiments of the present disclosure may incorporate optical elements, components and systems described in the US application entitled "Lighting Systems", Control No., Proxy 59373US002, and the US application entitled "Lighting System Light Collector" "Proxy Control number 59516US002, filed in conjunction with the present disclosure, the descriptions of which are hereby incorporated by reference to the extent to which they are not inconsistent with the present disclosure. Furthermore, the present disclosure contemplates the inclusion of additional optical elements in exemplary embodiments of lighting systems constructed in accordance with the present disclosure, as would be known to those skilled in the art. Those skilled in the art will also readily appreciate that the embodiments of the present disclosure can be used with a variety of light sources, including white LEDs and colored LEDs (e.g., red, blue, green or other colors). REGB LEDs will typically achieve the best color performance, but white LEDs are acceptable for many applications. It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention.

Claims (49)

1. CLAIMS Having described the invention as above, the content of the following claims is claimed as property: 1. A light source module characterized in that it comprises an emitter having a light emitting surface and a pyramidal collector mounted on the emitter on the emitting surface , the pyramidal collector has a proximal end facing the emitting surface and a distal end oriented away from the emitting surface.
2. 2. The light source module according to claim 1, characterized in that the proximal end of the pyramidal collector is in contact with the light emitting surface.
3. 3. The light source module according to claim 1, characterized in that the proximal end of the pyramidal collector has dimensions and shape that approximate the same dimensions and shape of the emitting surface.
4. 4. The light source module according to claim 1, characterized in that the proximal end has a generally square shape and a distal end has a generally square shape.
5. The light source module according to claim 1, characterized in that the proximal end has a generally square shape and the distal end has a generally rectangular shape.
6. The light source module according to claim 1, characterized in that the proximal end of the pyramidal collector is mounted around the emitting surface.
7. The light source module according to claim 1, characterized in that it additionally comprises a section of straight rectangular tube disposed adjacent the distal end of the pyramidal collector.
8. 8. The light source module according to claim 1, characterized in that it additionally comprises a dome portion.
9. The light source module according to claim 8, characterized in that it additionally comprises a portion of straight tube disposed between the dome portion and the pyramidal collector.
10. 10. The light source module according to claim 8, characterized in that it additionally comprises a flange with a generally disc shape disposed between the dome portion and the pyramidal collector.
11. The light source module according to claim 1, characterized in that the distal end of the pyramidal collector has a generally pincushion configuration.
12. The light source module according to claim 1, characterized in that the pyramidal collector collects at least about 70 percent of the light emitted by the emitter.
13. The light source module according to claim 1, characterized in that a distance between the proximal and distal ends of the pyramidal collector is about 3 to 5 times longer than a longer diagonal of its distal end.
14. The light source module according to claim 1, characterized in that the pyramidal collector has sides tapering from about 2 to about 6 degrees from the distal end to the proximal end.
15. The light source module according to claim 1, characterized in that the pyramidal collector has sides that taper no more than about 10 degrees from the distal end to the proximal end.
16. 16. A lighting system, characterized in that it comprises: a plurality of light source modules, each of the light source modules comprises an emitter having a light emitting surface and a pyramidal collector mounted on the emitter on the surface emitter, each pyramidal collector has a proximal end facing the emitting surface and a distal end oriented away from the emitting surface; a lighting objective; and a system of optical elements arranged between the at least one light source module and the lighting objective.
17. 17. The lighting system according to claim 16, characterized in that the plurality of the light source modules is arranged in an array in an aperture that is not radially symmetric.
18. The lighting system according to claim 17, characterized in that the illumination target is an image forming device arranged to be illuminated at an angle and having a plurality of mirrors capable of rotating about a pivot axis, and wherein the opening that is not radially symmetric has a long dimension and a short dimension and is oriented such that the long dimension is aligned with the pivot axis of the mirrors of the image forming device.
19. 19. The lighting system according to claim 16, characterized in that the light source modules and the optical element system are configured to form a plurality of channels directed substantially towathe illumination target.
20. 20. The lighting system according to claim 19, characterized in that the light source modules are disposed tangentially and along a spherical surface.
21. 21. The lighting system according to claim 16, characterized in that the proximal end of each pyramidal collector is in contact with the emitting surface of the emitter on which the pyramidal collector is mounted.
22. 22. The lighting system according to claim 16, characterized in that the proximal end of each pyramidal collector has dimensions and shape that approximate the same dimensions and shape of the emitting surface of the emitter on which the pyramidal collector is mounted.
23. The lighting system according to claim 21, characterized in that the proximal end of each pyramidal collector has a generally square shape and a distal end has a generally square shape. 2 .
24. The lighting system according to claim 21, characterized in that the proximal end of each pyramidal collector has a generally square shape and the distal end has a generally rectangular shape.
25. 25. The lighting system according to claim 16, characterized in that the proximal end of each pyramidal collector is mounted around the emitting surface of the light source module on which the pyramidal collector is mounted.
26. 26. The lighting system according to claim 16, characterized in that each light source module further comprises a section of straight rectangular tube disposed adjacent the distal end of each pyramidal collector.
27. 27. The lighting system according to claim 16, characterized in that the light source module additionally comprises a dome portion.
28. The lighting system according to claim 27, characterized in that each light source module additionally comprises a portion of straight tube disposed between the dome portion and the pyramidal collector.
29. 29. The lighting system according to claim 27, characterized in that each light source module further comprises a generally disc-shaped rim disposed between the dome portion and the pyramidal collector.
30. 30. The lighting system according to claim 16, characterized in that the distal end of each pyramidal collector has a generally pincushion configuration.
31. 31. The lighting system according to claim 16, characterized in that each pyramidal collector collects at least about 70 percent of light emitted by the emitter on which the pyramidal collector is mounted.
32. 32. The lighting system according to claim 16, characterized in that a distance between the proximal and distal ends of each pyramidal collector is about 3 to 5 times longer than the larger diagonal of the distal end of the pyramidal collector.
33. 33. The lighting system according to claim 16, characterized in that each pyramidal collector has sides that taper from about 2 to about 6 degrees from the distal end to the proximal of that pyramidal collector.
34. 34. The lighting system according to claim 16, characterized in that each pyramidal collector has sides that taper no more than about 10 degrees from the distal end to the proximal of that pyramidal collector.
35. 35. The lighting system according to claim 16, characterized in that the proximal end of each pyramidal collector has a generally square shape and the distal end of each pyramidal collector has a generally square shape.
36. 36. The lighting system according to claim 16, characterized in that the proximal end of each pyramidal collector has a generally square shape and the distal end of each collector has a generally rectangular shape
37. 37. The lighting system in accordance with claim 16, characterized in that the optical element system is configured to represent the image of the distal end of each pyramidal collector on the illumination target.
38. 38. The lighting system according to claim 37, characterized in that the images of the emitting surfaces are substantially superimposed to form a lighting spot, filling that illumination spot with the lighting objective.
39. 39. The lighting system according to claim 37, characterized in that the images of the emitting surfaces are packed tightly to form a lighting spot, filling that illumination spot substantially to the lighting target.
40. 40. The lighting system according to claim 37, characterized in that the images of the emitting surfaces overlap to form a lighting spot, filling that lighting spot with the lighting objective.
41. 41. The lighting system according to claim 16, characterized in that a shape of at least one of the ends of the pyramidal collectors substantially coincides with a shape of the lighting target.
42. 42. The lighting system according to claim 41, characterized in that the shape of the lighting objective is substantially square.
43. 43. The lighting system according to claim 41, characterized in that the shape of the lighting objective is substantially rectangular.
44. 44. The light source module according to claim 1, characterized in that it additionally comprises a reflector that surrounds at least a portion of the pyramidal collector.
45. 45. The light source module according to claim 44, characterized in that the reflector is arranged close to the emitting surface.
46. 46. The light source module according to claim 44, characterized in that the reflector comprises a reflective coating, a metallic surface or a molded part.
47. 47. The lighting system according to claim 16, characterized in that each light source module additionally comprises a reflector that surrounds at least a portion of each pyramidal collector.
48. 48. The lighting system according to claim 47, characterized in that each reflector is arranged close to a emitting surface.
49. 49. The lighting system according to claim 47, characterized in that each reflector comprises a reflective coating, a metal surface or a molded part.