Abstract: Collection optics are used with one or more light emitting diodes to produce, e.g., collimated light. The collection optics are produced in multiple pieces including a small reflective ring that surrounds the one or more light emitting diodes. The reflective ring may be positioned relative to the LEDs, using a mesa upon which the LEDs are mounted, as a lateral positioning guide. A separate upper reflector uses the reflective ring as a lateral positioning guide during assembly. The reflective ring and the upper reflector include reflective sidewalls that are approximately continuous when the reflective ring and upper reflector are assembled.

Abstract: For mixing different light colors from different LEDs or energized phosphors, an elongated mixing tunnel is used having a reflective inner surface. LEDs of different colors are optically coupled along the length of the mixing tunnel and at a first end of the tunnel. Light coupled along the length of the tunnel is reflected by an angled dichroic mirror that selectively reflects the incoming color light towards a single output port of the mixing tunnel. The dichroic mirror passes all other colors of light being transmitted towards the output port of the tunnel. Two, three, or more colors of LEDs can be used. Efficient and compact ways to energize phosphors are also described. Other optical techniques are also described.

Abstract: A device includes a light emitting semiconductor device bonded to an optical element. In some embodiments, the optical element may be elongated or shaped to direct a portion of light emitted by the active region in a direction substantially perpendicular to a central axis of the semiconductor light emitting device and the optical element. In some embodiments, the semiconductor light emitting device and optical element are positioned in a reflector or adjacent to a light guide. The optical element may be bonded to the first semiconductor light emitting device by a bond at an interface disposed between the optical element and the semiconductor light emitting device. In some embodiments, the bond is substantially free of organic-based adhesives.

Abstract: Various optical techniques are described for obtaining a specified light output from an LED source. One technique uses a parabolic reflector surrounding an LED or LED array to create a collimated beam, and the light exit opening of the parabolic reflector is defined by a reflective disc with an opening of the desired size. Any generated light that is outside of the opening is reflected back into the parabolic reflector and re-reflected until the light exits the opening. For mixing different light colors from different LEDs or energized phosphors, a mixing tunnel is used. The mixing tunnel includes angled dichroic mirrors or angled polarizer mirrors that selectively reflect and pass selected colors or polarizations of light to a single output port of the mixing tunnel. Efficient and compact ways to energize phosphors are also described. Other optical techniques are also described.

Abstract: Collection optics are used with one or more light emitting diodes to produce, e.g., collimated light. The collection optics are produced in multiple pieces including a small reflective ring that surrounds the one or more light emitting diodes. The reflective ring may be positioned relative to the LEDs, using a mesa upon which the LEDs are mounted, as a lateral positioning guide. A separate upper reflector uses the reflective ring as a lateral positioning guide during assembly. The reflective ring and the upper reflector include reflective sidewalls that are approximately continuous when the reflective ring and upper reflector are assembled.

Abstract: Various optical techniques are described for obtaining a specified light output from an LED source. One technique uses a parabolic reflector surrounding an LED or LED array to create a collimated beam, and the light exit opening of the parabolic reflector is defined by a reflective disc with an opening of the desired size. Any generated light that is outside of the opening is reflected back into the parabolic reflector and re-reflected until the light exits the opening. For mixing different light colors from different LEDs or energized phosphors, a mixing tunnel is used. The mixing tunnel includes angled dichroic mirrors or angled polarizer mirrors that selectively reflect and pass selected colors or polarizations of light to a single output port of the mixing tunnel. Efficient and compact ways to energize phosphors are also described. Other optical techniques are also described.

Abstract: A device includes a light emitting semiconductor device bonded to an optical element. In some embodiments, the optical element may be elongated or shaped to direct a portion of light emitted by the active region in a direction substantially perpendicular to a central axis of the semiconductor light emitting device and the optical element. In some embodiments, the semiconductor light emitting device and optical element are positioned in a reflector or adjacent to a light guide. The optical element may be bonded to the first semiconductor light emitting device by a bond at an interface disposed between the optical element and the semiconductor light emitting device. In some embodiments, the bond is substantially free of organic-based adhesives.

Abstract: An illumination device uses a wavelength converting element, such as a phosphor layer, that is physically separated from a light source, such as one or more light emitting diodes, a Xenon lamp or a Mercury lamp. The wavelength converting element is optically separated from the light source, so that the converted light emitted by the wavelength converting element is prevented from being incident on the light source. Accordingly, the temperature limitations of the wavelength converting element are removed, thereby permitting the light source to be driven with an increased current to produce a higher radiance. Moreover, by optically separating the wavelength converting element from the light source, the conversion and recycling efficiency of the device is improved, which also increases radiance.

Abstract: A compact backlight system for illuminating a display device (12) has a light-emitting panel (1) with a front wall (2) and an opposed rear wall (3) and with edge surfaces (4, 5). At least one of the edge surfaces (4) is light-transmitting. The backlight system has a light source (6) comprising a limited number of LEDs. Light from the light source (6) is coupled into the light-emitting panel (1) via the edge surface that is light-transmitting. According to the invention, the light-emitting panel (1) is wedge-shaped, and the surface area Si of the light-transmitting edge surface (4) and the surface area Sr of the opposite edge surface (5) fulfill the relation: 1<(Sr/Si)<10, preferably 1.5<(Sr/Si)<5. Light travelling for the first time from the light-transmitting edge surface through the light-emitting panel (1) towards the opposite edge surface (5) cannot be coupled out of the light emitting panel (1).

Abstract: A light emitting device includes a light emitting diode (LED), a concentrator element, such as a compound parabolic concentrator, and a wavelength converting material, such as a phosphor. The concentrator element receives light from the LED and emits the light from an exit surface, which is smaller than the entrance surface. The wavelength converting material is, e.g., disposed over the exit surface. The radiance of the light emitting diode is preserved or increased despite the isotropic re-emitted light by the wavelength converting material. In one embodiment, the polarized light from a polarized LED is provided to a polarized optical system, such as a microdisplay. In another embodiment, the orthogonally polarized light from two polarized LEDs is combined, e.g., via a polarizing beamsplitter, and is provided to non-polarized optical system, such as a microdisplay. If desired, a concentrator element may be disposed between the beamsplitter and the microdisplay.

Abstract: A compact illumination system that is suitable for, e.g., projection systems, includes a plurality of light emitting diodes that are aligned along the same axis. The illumination system includes mirrors and a filter system for combining the light emitted by the different light emitting diodes. The light emitting diodes may be mounted within the same plane, e.g., on the same heatsink, which simplifies assembly and alignment of the system. Moreover, a collimator system with integrally formed refractive and/or reflective collimators, may be used. The use of an integrally formed collimator system advantageously reduces the number of piece parts and simplifies assembly.

Abstract: The luminance of a system that includes a light emitting diode (LED), such as a projection system, may be increased by using an LED chip that has a light emitting surface that emits light directly into any medium with a refractive index of less than or equal to approximately 1.25. For example, the LED chip may emit light directly into the ambient environment, such as air or gas, instead of into an encapsulant. The low refractive index decreases the étendue of the LED, which increases luminance. Moreover, without an encapsulant, a collimating optical element, such as a lens, can be positioned close to the light emitting surface of the LED chip, which advantageously permits the capture of light emitted at large angles. A secondary collimating optical element may be used to assist in focusing the light on a target, such as a micro-display.

Abstract: The amount of usefully captured light in an optical system is increased by concentrating light in a region where it can be collected by the optical system. In one embodiment, a light emitting diode is disposed on a first surface of a transparent member, which includes an exit surface. The transparent member includes a reflective element on a second surface and is shaped such that light emitted from the light emitting diode is directed toward the exit surface. A portion of the first surface of the transparent member between the first light emitting diode and the exit surface of the transparent member first surface is coated with a reflective coating. The portion of the first surface with the reflective coating may be larger than the width of the light emitting diode. In one embodiment, the transparent member is formed from two separate transparent elements.

Abstract: A compact backlight system for illuminating a display device has a front wall and a rear wall situated opposite thereto. At least one light source comprising a light-emitting diode is provided with a translucent lens shaped cover. The system has at least one light input structure for coupling light from the light source into the light-emitting panel. During operation, light originating from the light source is incident on the light input structure and distributes itself in the light-emitting panel. According to the invention the light input structure is conically or frustoconically shaped towards the light source. The thickness dp of the light-emitting panel is smaller than the diameter dc of the translucent lens-shaped cover of the light source. Preferably, the light input structure is of prismatic or pyramidal shape.

Abstract: A device includes a light emitting semiconductor device bonded to an optical element. In some embodiments, the optical element may be elongated or shaped to direct a portion of light emitted by the active region in a direction substantially perpendicular to a central axis of the semiconductor light emitting device and the optical element. In some embodiments, the semiconductor light emitting device and optical element are positioned in a reflector or adjacent to a light guide. The optical element may be bonded to the first semiconductor light emitting device by a bond at an interface disposed between the optical element and the semiconductor light emitting device. In some embodiments, the bond is substantially free of organic-based adhesives.