3205 results about "Color temperature" patented technology

A method and system allow a lighting device having light sources with multiple color temperatures to vary a color temperature of the lighting device in response to changing dimming levels. The light sources are non-incandescent light sources, such as light emitting diodes and/or gas-discharge lights. A dimmer circuit provides a dimming signal that indicates a selected dimming level. The lighting device includes a light source driver and a light source driver controller that cooperate to vary drive currents to the light sources in response to the selected dimming level. By varying the drive currents in different relative amounts, the color temperature of the lighting device changes in response to dimming level changes. In at least one embodiment, changes in the color temperature of the lighting device in response to the dimming level changes simulates the color temperature changes of an incandescent light source.

A light emitting device having an encapsulant with scattering features to tailor the spatial emission pattern and color temperature uniformity of the output profile. The encapsulant is formed with materials having light scattering properties. The concentration of these light scatterers is varied spatially within the encapsulant and/or on the surface of the encapsulant. The regions having a high density of scatterers are arranged in the encapsulant to interact with light entering the encapsulant over a desired range of source emission angles. By increasing the probability that light from a particular range of emission angles will experience at least one scattering event, both the intensity and color temperature profiles of the output light beam can be tuned.

Methods and apparatus for generating and modulating white light illumination conditions. Examples of applications in which such methods and apparatus may be implemented include retail environments (e.g., food, clothing, jewelry, paint, furniture, fabrics, etc.) or service environments (e.g., cosmetics, hair and beauty salons and spas, photography, etc.) where visible aspects of the products/services being offered are significant in attracting sales of the products/services. Other applications include theatre and cinema, medical and dental implementations, as well as vehicle-based (automotive) implementations. In another example, a personal grooming apparatus includes one or more light sources disposed in proximity to a mirror and configured to generate variable color light, including essentially white light, whose color temperature may be controlled by a user.

A method of controlling brightness, colour, hue, colour temperature, gamma response or contrast of at least one image for display on a multi-layer display device characterized by carrying out the steps of: receiving said at least one image(s) to be displayed, detecting the brightness, colour, hue, colour temperature, gamma response or contrast of said image(s) to be displayed, determining the transmissivity of each layer of the multi layer display device in the localized area of said image(s) to achieve the brightness, colour, hue, colour temperature, gamma response and/or contrast detected or received, communicating the determined transmissivity of each layer of the multi layer display device in the localized area of said image(s) to a display device or storage device. A software device designed to do the same and a display device which can be utilized to controlling brightness, colour, hue, colour temperature, gamma response or contrast of at least one image.

Illumination devices and related systems and methods are closed that can be used for LCD (Liquid Crystal Display) backlights, LED lamps, or other applications. The illumination devices can include a photo detector, such as a photodiode or an LED or other light detecting device, and one or more LEDs of different colors. A related method can be implemented using these illumination devices to maintain precise color produced by the blended emissions from such LEDs. One application for the illumination devices is backlighting for FSC (Field Sequential Color) LCDs (Liquid Crystal Displays). FSC LCDs temporally mix the colors in an image by sequentially loading the red, green, and blue pixel data of an image in the panel and flashing the different colors of an RGB backlight. Precise and uniform color temperature across such a display can be advantageously maintained by continually monitoring ratios of photodiode currents induced by the different colored LEDs in each illumination device as each color is flashed.

Provided herein are methods and systems for illuminating environments, including aircraft environments. The methods and systems include facilities for providing both white and non-white illumination, with color and color temperature control, in programmed response to inputs. Methods and systems are also provided for improving the addressing of light systems in a network lighting configuration.

Embodiments of the invention provide lighting assemblies for installation in lighting fixtures. Lighting assemblies include at least one light source, at least one heat sink, and at least one reflector. Other embodiments of the lighting assembly may also include an outer surface of the reflector comprising a heat sink. In some embodiments, it may be desirable to direct light toward a wall. In those situations, a wall wash trim may be included. The lighting assemblies disclosed herein may be modular and thus replaced without having to uninstall the entire fixture. In some embodiments, a circuit board containing at least one light emitting diode in an existing lighting assembly may be replaced with another circuit board containing light emitting diodes of a different color temperature or a different color.

A white light LED is described that uses an LED die that emits visible blue light in a wavelength range of about 450-470 nm. A red phosphor or quantum dot material converts some of the blue light to a visible red light having a peak wavelength between about 605-625 nm with a full-width-half-maximum (FWHM) less than 80 nm. A green phosphor or quantum dot material converts some of the blue light to a green light having a FWHM greater than 40 nm, wherein the combination of the blue light, red light, and green light produces a white light providing a color rendering of R_a,8>90 and a color temperature of between 2500K-5000K. Preferably, the red and green converting material do not saturate with an LED die output of 100 W/cm² and can reliably operate with an LED die junction temperature over 100 degrees C.

A white point adjusting apparatus is provided to adjust an achromatic color level for an input video signal including a plurality of color signals, and display an adjusted image on a liquid crystal module. This adjusting apparatus comprises: a first table for setting a white point by deciding an offset quantity of at least one color signal from a highest gray level for each color temperature; a second table for setting an offset quantity of the color signal to converge a halftone white point for each color temperature set by the first table; and a white point adjusting unit for adding the offset quantities set by the first and second tables and to the input video signal.

A backlight module is provided, comprising a light emitting diode (LED), a light guide plate and a fluorescence material. The fluorescence material is disposed in a transmission path of a first light or within the light guide plate. Then the fluorescence material is excited by the first light to generate one or more second lights. The first light and the second light are mixed or the second lights with different wavelengths are mixed to form a white light to generate a plane light source with a desired color temperature.

A system and related techniques generate and present a set of linked, dynamically interactive image processing controls for image editing and optimization tasks. In embodiments a user interface may present a set of global editing modes such as color manipulation, exposure correction or others. Each mode may contain a hierarchical set of basic, intermediate and advanced controls such as one-button automatic fixes, color or saturation sliders or editable histograms or other curves. When a user wishes, for instance, to achieve a warmer color balance or perform other color-correction tasks, the system may automatically detect adjustments in one or more parameters, such as CMYK values, and automatically adjust the values of other parameters to enhance the intended correction or action. For instance when the magenta content on a CMYK slider is increased, the color saturation may be slightly increased or color temperature may be slightly raised, to create a warmer appearance in the color cast of the image. Other combinations of image parameters may be linked. According to embodiments, a set of editable curves such as histograms or gamma curves may be dragged or otherwise adjusted or manipulated by users, and saved for re-application to other images or at other times.

A color/color temperature tunable light emitting device comprises: an excitation source (LED) operable to generate light of a first wavelength range and a wavelength converting component comprising a phosphor material which is operable to convert at least a part of the light into light of a second wavelength range. Light emitted by the device comprises the combined light of the first and second wavelength ranges. The wavelength converting component has a wavelength converting property (phosphor material concentration per unit area) that varies spatially. The color of light generated by the source is tunable by relative movement of the wavelength converting component and excitation source such that the light of the first wavelength range is incident on a different part of the wavelength converting component and the generated light comprises different relative proportions of light of the first and second wavelength ranges.

LED calibration systems and related methods are disclosed that use the photo-sensitivity of LEDs to correct for variations between LEDs during initial production and over the lifetime of systems using LEDs. The disclosed systems and methods include methods to set the color or color temperature produced by a group of LEDs during the manufacturing of a device such as a lamp, an LED display, or an LCD backlight, and maintaining such color or color temperature over the operating life of such a device. The methods involve measuring the intensity and/or wavelength of light produced by each LED within a group of LEDs and adjusting an amount of light generated by the LEDs to produce precise color and intensity from the group of LEDs. Two methods that operate some of the LEDs in photovoltaic or photoconductive mode to measure the light intensity produced by other LEDs in the group are presented. The first method uses an additional light source as a reference and determines the light intensity emitted from each LED relative to such reference, while the second method determines the light intensity emitted from each LED relative to each other.

A device and method for automatically adjusting an image condition in a display is, disclosed. The present device and method optimizes the image condition of a display according to individual preferences by taking into account the brightness and color temperature set initially by a user. Particularly, the present invention includes a photo sensor to detect the environmental illumination and a micro processor utilizing the detected data to appropriately adjust the image condition with respect to a user <CUSTOM-CHARACTER FILE="US06292228-20010918-P00001.TIF" ID="CUSTOM-CHARACTER-00001"> preference.

Lighting control system includes lighting fixture having identification information, controller for setting lighting condition for dimming level and color temperature of illumination light of lighting fixture, and dimmer for outputting dimming signal to lighting fixture. Lighting fixture includes dimmer for modulating illumination light to superpose thereon information signal containing identification information and lighting information of lighting fixture. Controller includes wireless communication unit for outputting control signal to dimmer, display unit with touch panel, for displaying image of lighting fixture, and visible light receiver for reading identification information and lighting information from information signal superposed on illumination light. Display unit is configured to associate identification information read through visible light receiver with image of lighting fixture to display image so as to reflect lighting information.

The present invention provides a light emitting device comprising a first light emitting portion that emits white light at a color temperature of 6000K or more and a second light emitting portion that emits white light at a color temperature of 3000K or less, which include light emitting diode chips and phosphors and are independently driven. The present invention has an advantage in that a light emitting device can be diversely applied in a desired atmosphere and use by realizing white light with different light spectrums and color temperatures. Particularly, the present invention has the effect on health by adjusting the wavelength of light or the color temperature according to the circadian rhythm of humans.

An electric lamp includes a first light source and a second light source and power circuitry configured to selectively energize the first light source and the second light source. The first light source is configured to produce light that is substantially free of wavelengths below about 530 nanometers, and the second light source is configured to product light having wavelengths of less than about 530 nanometers. The electric lamp is configured to produce white or near-white light in a variety of color temperatures, while retaining good color rendering index.

An illumination apparatus having adjustable color temperature and a method for adjusting the color temperature. The apparatus and the method can adjust the color temperature for different purposes. The illumination apparatus comprises: a blue-light source; a transparent filter lens set on the top of the blue-light source; a fluorescence layer of cerium-doped yttrium aluminum garnet (YAG) phosphor is spread onto the transparent filter lens. Replacing the yttrium and the aluminum in the cerium-doped yttrium aluminum garnet phosphor with gadolinium (Gd) and gallium (Ga) respectively can produce yellow lights of different wavelengths. Different yellow lights can then be mixed with the blue light to produce white lights of different color temperature.

A white-light electro-luminescent lamp having an adjustable spectral power distribution, including a first light-emitting element which emits light within each of three wavelength bands, 1) between 440 and 520 nm, 2) between 520 and 600 nm, and 3) between 600 and 680 nm. A second light-emitting element emits light within each of three wavelength bands, 1) between 440 and 520 nm, 2) between 520 and 600 nm, and 3) between 600 and 680 nm. A controller modulates the integrated spectral power of the light produced by the first and the second light-emitting elements such that the spectral power distribution of the light formed by combining the light produced by the modulated first and second light-emitting elements is substantially equal to a CIE standard daylight spectral power distribution for correlated color temperatures between 4000K-9500K.

A digital camera (10) includes a face detecting section (74), a color temperature detecting section (76) and a flash device (86) having an LED array in which RGB LEDs are regularly arranged as a light source. When a shutter button (18) is pressed halfway, the face detecting section (74) reads out image data of a through image from a memory (60) and detects a person's face in the image. A CPU (64) identifies a scene based on brightness values of face and surrounding areas as, for example, a backlit scene, and specifies a face peripheral area according to an exposure pattern corresponding to the backlit scene. When the shutter button (18) is fully pressed, the CPU (64) sends a flash projection command to an LED control circuit (87), thereby illuminating the LEDs corresponding to the face peripheral area. By controlling illumination of the RGB LEDs, the LED control circuit (87) directs to project the flash light having color temperature that corrects the person's face color into an appropriate skin color.

To provide a light emitting device having a phosphor mixture and a light emitting part, the phosphor mixture including a red phosphor and more than one kind of phosphor having an emission spectrum with a peak in a wavelength range from 500 nm to 630 nm, and emitting light having a sufficient luminance and excellent in color rendering properties not only in a white light with high correlated color temperature, but also in a warm white light with low correlated color temperature. CaAlSiN₃:Eu manufactured as a red phosphor and and CaAl₂Si₄N₈:Eu manufactured as an orange phosphor, and for example, commercial YAG:Ce as a yellow-green phosphor, are prepared, and emission spectra of these phosphors are measured when excited by excitation light in the wavelength range from 430 nm to 500 nm. Further, the emission spectrum of the light used as an excitation light are measured, by simulation using their emission spectra, a mixing ratio of each phosphor, by which the correlated color temperature of the phosphor mixture becomes a target color temperature, is obtained. And based on the result of the simulation, each phosphor is measured nad mixed, thus obtaining the phosphor mixture.

There is provided a light-emitting apparatus with favorable radiation light intensity, which is excellent in light extraction efficiency, color temperature and color rendering property. The light-emitting apparatus includes a light-emitting element, a base body having, on its top surface, a placement portion for emplacing thereon the light-emitting element, a frame body attached to the top surface of the base body so as to surround the placement portion, a light transmitting member disposed inside the frame body so as to cover the light-emitting element, and phosphors contained in the light transmitting member, which performs wavelength conversion on the light emitted from the light-emitting element. The light transmitting member has a pre-cured viscosity ranging from 0.4 to 50 Pa.s.

A method and system allow a lighting device having light sources with multiple color temperatures to vary a color temperature of the lighting device in response to changing dimming levels. The light sources are non-incandescent light sources, such as light emitting diodes and/or gas-discharge lights. A dimmer circuit provides a dimming signal that indicates a selected dimming level. The lighting device includes a light source driver and a light source driver controller that cooperate to vary drive currents to the light sources in response to the selected dimming level. By varying the drive currents in different relative amounts, the color temperature of the lighting device changes in response to dimming level changes. In at least one embodiment, changes in the color temperature of the lighting device in response to the dimming level changes simulates the color temperature changes of an incandescent light source.

Automatic white balancing and/or autoexposure as useful in a digital camera extracts color channel gains from comparisons of image colors with reference colors under various color temperature illuminants and/or extracts exposure settings from illuminance mean, illuminance variance, illuminance minimum, and illuminance maximum in areas of an image with a trained neural network.

A light emitting device capable of emitting light having various color temperatures is disclosed. The light emitting device includes a first light emitting part emitting a daylight color having a color temperature of 6000 K or more, a second light emitting part emitting white light having a color temperature less than 6000 K, and a third light emitting part emitting light in a visible range of 580 nm or more. The second and third light emitting parts are operable independently of the first light emitting part, and realize a warm white color having a color temperature of 3000 K or less with the white light emitted from the second light emitting part and the light emitted from the third light emitting part. The light emitting device realizes white light of various spectra and color temperatures corresponding to desired mood and utility. The light emitting device is controlled to emit light having a suitable wavelength or a suitable color temperature depending on the circadian rhythm of human, thereby enabling improvement of the user's health.

A light source for categorical color perception has major light emitting bands in ranges from 530 to 580 and from 600 to 650, with correlated color temperature of the lamp light color in a range from 1700 to 6500 and with DUV (distance from perfect radiator locus on UV coordinates) in a range from 0 to 70, and allows categorical perception of at least red, green, blue, yellow and white of surface colors of an illuminated object.

To provide a phosphor mixture realizing a light emitting device having a phosphor and a light emission element, by which light emission is performed, with a small color shift due to a feeding current and having an excellent color rendering properties. CaAlSin3:Eu as a red phosphor and YAG:Ce as a yellow phosphor are manufactured, and emission spectra thereof are obtained. Meanwhile, the emission spectrum of an excitation light emitted by a light emitting part is obtained. From the emission spectra thus obtained, a relative mixing ratio of each phosphor is obtained by simulation, so that a correlated color temperature of the light emitting device becomes a target temperature. Then, based on the relative mixing ratio thus obtained, each phosphor is measured and mixed, and a phosphor mixture is thereby obtained.

An LED device and an LED lighting apparatus using the same can include a casing including a cavity and at least one pair of LED chips including a first and second LED chips. The LED chips can be adjacently located in the cavity, and an encapsulating resin including a phosphor can be disposed in the cavity so as to encapsulate the LED chips. A light-emitting surface of the first LED chip can be covered with a transparent resin, and therefore color temperatures of light emitted from the first and second LED chips can be located on a substantially black body due to a difference between their distances to the encapsulating resin. Thus, the LED lighting apparatus using the LED device can selectively emit white light having a preferable color temperature that is close to a natural color between the color temperatures by adjusting current applied to the LED chips.

An embodiment of a collimating downlight has front-mounted blue LED chips facing upwards, having a heat sink on the back of the LED chips exposed in ambient air. The LED chips are mounted in a collimator that sends their blue light to a remote phosphor situated near the top of the downlight can. Surrounding the remote phosphor is a downward-facing reflector that forms a beam from its stimulated emission and reflected blue light. The phosphor thickness and composition can be adjusted to give a desired color temperature.

A hybrid light source comprises a high-efficiency lamp, for example, a fluorescent lamp, and a low-efficiency lamp, for example, a halogen lamp. A control circuit individually controls the amount of power delivered to each of the high-efficiency lamp and the low-efficiency lamp, such that a total light output of the hybrid light source ranges throughout a dimming range from a minimum total intensity to a maximum total intensity. The high-efficiency lamp is turned off and the low-efficiency lamp produces all of the total light intensity of the hybrid light source when the total light intensity is below a transition intensity. The low-efficiency lamp is controlled such that the correlated color temperature of the hybrid light source decreases as the total light intensity is decreased below the transition intensity. The hybrid light source is characterized by a low impedance throughout the dimming range.