Abstract: An array of pixels in a display may be illuminated by a backlight having an array of light-emitting diodes in an array of respective cells. A reflector is used to reflect light from the light-emitting diodes through the array of pixels. Within the cells, the reflector has cross-sectional profiles that help distribute light emitted from the light-emitting diodes toward edges of the cells. A light diffuser layer for the backlight may have a partially reflective layer such as a thin-film interference filter with an angularly dependent transmission. Within each cell, the reflector may have cross-sectional profiles with portions that are parabolic or elliptical.

Abstract: A display may have a pixel array such as a liquid crystal pixel array. The pixel array may be illuminated by a backlight unit that includes an array of light-emitting diodes. A backlight brightness selection circuit may select brightness values for the light-emitting diodes. The backlight brightness selection circuit may select the brightness values based on image data, based on brightness values used in previous image frames, based on device information, and/or based on sensor information. The backlight brightness selection circuit may select the backlight brightness levels to mitigate visible artifacts such as flickering and halo. The backlight levels selected by the backlight brightness selection may be modified by a power consumption compensation circuit. The power consumption compensation circuit may estimate the amount of power consumption required to operate the backlight using the target brightness levels and may modify the target brightness levels to meet maximum power consumption requirements.

Abstract: An array of pixels in a display may be illuminated by a backlight having an array of light-emitting diodes in an array of respective cells. A reflector is used to reflect light from the light-emitting diodes through the array of pixels. Within the cells, the reflector has cross-sectional profiles that help distribute light emitted from the light-emitting diodes toward edges of the cells. A light diffuser layer for the backlight may have a partially reflective layer such as a thin-film interference filter with an angularly dependent transmission. Within each cell, the reflector may have cross-sectional profiles with portions that are parabolic or elliptical.

Abstract: A display such as a liquid crystal display may have an array of pixels that is illuminated using backlight illumination from a backlight. The backlight may have a light guide plate that distributes light from light-emitting diodes across the display. The light-emitting diodes may be overlapped by the light guide plate and may emit light into portions of the light guide plate that have ramped profiles. Light-emitting diodes for the backlight may have multiple light-emitting diode dies mounted on common package substrates. Reflective walls may be formed between the light-emitting diode dies on a substrate. Phosphor may cover the dies. The light-emitting diodes may contain four light-emitting diode dies that emit light in four different directions. Two or more of the dies may emit light of different colors. Light may be emitted into the corners of rectangular light distribution regions of a light guide plate.

Abstract: An electrodeless plasma lamp having a lamp body and a power source configured to provide radio-frequency (RF) power via a feed to the lamp body is provided. The lamp includes a first conductive element and a second conductive element. The first conductive element has a first side with a first protrusion. The second conductive element has a second side with a second protrusion. The first side and second side face each other and spaced apart by a first distance and configured to couple the RF power via an electric field to a fill to form at least one plasma arc. The first protrusion and the second protrusion extend towards each other and are spaced apart by a second distance that is less than the first distance. The first and second protrusions may provide localized enhancement of the electric field at the first side and the second side.

Abstract: An electrodeless plasma lamp is described that employs acoustic resonance. The plasma lamp includes a metal enclosure having a conductive boundary forming a resonant structure, and a radio frequency (RF) feed to couple RF power from an RF power source into the resonant cavity. A bulb is received at least partially within an opening in the metal enclosure. The bulb contains a fill that forms a light emitting plasma when the power is coupled to the fill. The RF power source includes a controller to modulate the RF power to induce acoustic resonance in the plasma.

Abstract: An electrodeless plasma lamp and a method of generating light are described. The lamp may comprise a lamp body including a dielectric material. The bulb is positioned proximate the lamp body and contains a fill that forms a plasma when radio frequency (RF) power is coupled to the fill. The conductive element is located within the lamp body and configured to enhance coupling of the RF power to the fill. The lamp may include a feed coupled to the RF power source and configured to radiate power into the lamp body. The at least one conductive element is configured to enhance the coupling of radiated power from the feed to the fill. In an example, two spaced apart conductive elements may be located within the lamp body. The bulb may be an elongated bulb having opposed ends, each opposed end of the bulb being proximate a corresponding conductive element.

Abstract: An electrodeless plasma lamp and method of generating light are described. The lamp may comprise a lamp body, a source of radio frequency (RF) power and a bulb. The lamp body may comprise a solid dielectric material and at least one conductive element within the solid dielectric material. The source of RF power is configured to provide RF power and an RF feed configured to radiate the RF power from the RF source into the lamp body. The bulb is positioned proximate the lamp body and contains a fill that forms a plasma when the RF power is coupled to the fill from the lamp body. The at least one conductive element is configured to concentrate an electric field proximate the bulb.

Abstract: An electrodeless plasma lamp and method of forming a seal on an electrodeless bulb for use in the plasma lamp are described. The method may include providing a section of tube, cutting the tube to length, and sealing a first point on one end of the tube in a rounded fashion to form a first end of the electrodeless bulb. The cross-sectional diameter of an opposite end of the tube is reduced to form a tail on the electrodeless bulb. The tail is open to an interior portion of the bulb where the interior portion forms a cavity. One or more fill gases are injected into the cavity of the bulb. A first portion along the tail of the bulb is sealed thereby forming a truncated tail. A second point on the tail, intermediate between a terminal portion of the tail and a portion of the bulb containing the cavity, is sealed. The second point is sealed with a plasma torch by using an inert-gas element with a minimum of hydrogen gas.

Abstract: A lamp and methods of forming are shown. In one example, a dielectric layer is formed over a gap between conductors in a plasma lamp. Electric arcing is reduced or eliminated, thus allowing tighter gaps and/or higher voltages. In one example a glass frit method is used to apply the dielectric layer. A lamp is shown with a barrier layer that prevents tarnish such as tarnish from sulfur exposure. The barrier layer reduces or prevents degradation of the lamp due to conversion of a conductor material to non-conductive tarnish material.

Abstract: An electrodeless plasma lamp and method of generating light are described. The lamp may comprise a lamp body, a source of radio frequency (RF) power and a bulb. The lamp body may comprise a solid dielectric material and at least one conductive element within the solid dielectric material. The source of RF power is configured to provide RF power and an RF feed configured to radiate the RF power from the RF source into the lamp body. The bulb is positioned proximate the lamp body and contains a fill that forms a plasma when the RF power is coupled to the fill from the lamp body. The at least one conductive element is configured to concentrate an electric field proximate the bulb.

Abstract: An electrodeless plasma lamp and method of generating light are described. The lamp may comprise a lamp body, a source of radio frequency (RF) power and a bulb. The lamp body may comprise a solid dielectric material and at least one conductive element within the solid dielectric material. The source of RF power is configured to provide RF power and an RF feed configured to radiate the RF power from the RF source into the lamp body. One or more tuning mechanisms allow tuning of the lamp body to a given resonant frequency. The bulb is positioned proximate the lamp body and contains a fill that forms a plasma when the RF power is coupled to the fill from the lamp body. The at least one conductive element is configured to concentrate an electric field proximate the bulb.

Abstract: A lamp and methods of forming are shown. In one example, a dielectric layer is formed over a gap between conductors in a plasma lamp. Electric arcing is reduced or eliminated, thus allowing tighter gaps and/or higher voltages. In one example a glass frit method is used to apply the dielectric layer. A lamp is shown with a barrier layer that prevents tarnish such as tarnish from sulfur exposure. The barrier layer reduces or prevents degradation of the lamp due to conversion of a conductor material to non-conductive tarnish material.

Abstract: An electrodeless plasma lamp and method of generating light are described. The lamp may comprise a lamp body, a source of radio frequency (RF) power and a bulb. The lamp body may comprise a solid dielectric material and at least one conductive element within the solid dielectric material. The source of RF power is configured to provide RF power and an RF feed configured to radiate the RF power from the RF source into the lamp body. The bulb is positioned proximate the lamp body and contains a fill that forms a plasma when the RF power is coupled to the fill from the lamp body. The at least one conductive element is configured to concentrate an electric field proximate the bulb.

Abstract: A lamp and methods of forming are shown. In one example, a dielectric layer is formed over a gap between conductors in a plasma lamp. Electric arcing is reduced or eliminated, thus allowing tighter gaps and/or higher voltages. In one example a glass frit method is used to apply the dielectric layer. A lamp is shown with a barrier layer that prevents tarnish such as tarnish from sulfur exposure. The barrier layer reduces or prevents degradation of the lamp due to conversion of a conductor material to non-conductive tarnish material.

Abstract: An electrodeless plasma lamp and method of generating light are described. The lamp may comprise a lamp body, a source of radio frequency (RF) power and a bulb. The lamp body may comprise a solid dielectric material and at least one conductive element within the solid dielectric material. The source of RF power is configured to provide RF power and an RF feed configured to radiate the RF power from the RF source into the lamp body. One or more tuning mechanisms allow tuning of the lamp body to a given resonant frequency. The bulb is positioned proximate the lamp body and contains a fill that forms a plasma when the RF power is coupled to the fill from the lamp body. The at least one conductive element is configured to concentrate an electric field proximate the bulb.

Abstract: An electrodeless plasma lamp and method of generating light are described. The lamp may comprise a lamp body, a source of radio frequency (RF) power and a bulb. The lamp body may comprise a solid dielectric material and at least one conductive element within the solid dielectric material. The source of RF power is configured to provide RF power and an RF feed configured to radiate the RF power from the RF source into the lamp body. One or more tuning mechanisms allow tuning of the lamp body to a given resonant frequency. The bulb is positioned proximate the lamp body and contains a fill that forms a plasma when the RF power is coupled to the fill from the lamp body. The at least one conductive element is configured to concentrate an electric field proximate the bulb.

Abstract: Electrodeless plasma lamp and fill is described. Power may be over coupled to the lamp during startup and a significant percentage of the power is reflected. In some examples, 40-80% of the power may be initially reflected and less than 100 watts of forward power may be provided to the lamp. A high pressure fill is used to increase resistance and coupling of power during startup. In one example, a fill of noble gas, Mercury and metal halide is used and the high pressure decreases the warm up time required to vaporize the Mercury and metal halide. In some embodiments, the pressure may be between 200 Torr to 3000 Torr. A combination of metal halides may be used to provide desired characteristics. For example, Aluminum Halide, Indium Halide and/or Thallium Halide may be combined with one or more metal halides having a metal from the Lanthanide series.

Abstract: An electrodeless plasma lamp and a method of generating light are described. The lamp may comprise a lamp body including a dielectric material. The bulb is positioned proximate the lamp body and contains a fill that forms a plasma when radio frequency (RF) power is coupled to the fill. The conductive element is located within the lamp body and configured to enhance coupling of the RF power to the fill. The lamp may include a feed coupled to the RF power source and configured to radiate power into the lamp body. The at least one conductive element is configured to enhance the coupling of radiated power from the feed to the fill. In an example, two spaced apart conductive elements may be located within the lamp body. The bulb may be an elongated bulb having opposed ends, each opposed end of the bulb being proximate a corresponding conductive element.

Abstract: An electrodeless plasma lamp comprising a lamp housing and a lamp body releasably received with the lamp housing. The lamp housing includes a first electrical connector operatively coupled a power source to provide radio frequency (RF) power. The lamp body includes a second electrical connector to releasably engage with the first electrical connector of the lamp housing. The lamp body includes a dielectric material having a relative permittivity greater than 2. RF power is coupled by the lamp body to a bulb containing a fill that forms a light emitting plasma. In an example embodiment, the plasma lamp includes a retaining arrangement releasably to retain the lamp body at least partially within the lamp housing.