3242 results about "Photoluminescence" patented technology

A coated nanocrystal capable of light emission includes a substantially monodisperse nanoparticle selected from the group consisting of CdX, where x=S, Se, Te and an overcoating of ZnY, where Y=S, Se, uniformly deposited thereon, said coated nanoparticle characterized in that when irradiated the particles exhibit photoluminescence in a narrow spectral range of no greater than about 60 nm, and most preferably 40 nm, at full width half max (FWHM). The particle size of the nanocrystallite core is in the range of about 20 Å to about 125 Å, with a deviation of less than 10% in the core. The coated nanocrystal exhibits photoluminescence having quantum yields of greater than 30%.

A process for producing any photoluminescent printed polychromatic image (8), and the image obtained thereby. At least one set of at least three monochromatic filtered images (6a, 6b, 6c) is prepared from any original polychromatic image (1) visible in visible light which is filtered with a spectral pass-band below or equal to 15 nm, according to at least three wavelengths of fundamental colors equal to the wavelengths of the luminescent pigments used, with the corresponding monochromatic filtered images (6a, 6b, 6c), in order to print separately, one above the other, three monochromatic printed images (8a, 8b, 8c). The invention concerns the image obtained, a protective device and a document carrying such an image.

A photoluminescence color display comprises a display panel that displays red, green and blue pixel areas, an excitation source operable to generate excitation radiation for operating the display, and a photoluminescence color-element plate. The color-element plate comprises at least one photoluminescence material, such as a phosphor material or quantum dots, that is operable to emit light corresponding to red, green and blue pixel areas of the display in response to said excitation radiation. Additionally, the photo-luminescence color display comprises a wavelength selective filter that is provided between the color-element plate and the excitation source. The filter has a transmission characteristic that allows the passage of excitation radiation from the excitation source to excite the at least one photoluminescence material whilst preventing the passage of photoluminescence light back to the excitation source thereby prevent cross contamination of light among the different pixel areas of the display.

A photoluminescent capsule illuminator for a sighting device. The photoluminescent illuminator includes an elongated phosphor housing having sidewalls and a base. The photoluminescent illuminator includes phosphors in a granular form disposed inside the phosphor housing. The photoluminescent illuminator includes a cap sealing the phosphors in the phosphor housing. The phosphor housing is disposed in relation to a body of the sighting device such that photoluminescent light emitted from the phosphors exits the phosphor housing and identifies a location of a sight on the sighting device.

An optical manifold for efficiently combining a plurality of blue LED outputs to illuminate a phosphor for a single, substantially homogeneous output, in a small, cost-effective package. Embodiments are disclosed that use a single or multiple LEDs and a remote phosphor, and an intermediate wavelength-selective filter arranged so that backscattered photoluminescence is recycled to boost the luminance and flux of the output aperture. A further aperture mask is used to boost phosphor luminance with only modest loss of luminosity. Alternative non-recycling embodiments provide blue and yellow light in collimated beams, either separately or combined into white.

An electronic device comprising a population of quantum dots embedded in a host matrix and a primary light source which causes the dots to emit secondary light of a selected color, and a method of making such a device. The size distribution of the quantum dots is chosen to allow light of a particular color to be emitted therefrom. The light emitted from the device may be of either a pure (monochromatic) color, or a mixed (polychromatic) color, and may consist solely of light emitted from the dots themselves, or of a mixture of light emitted from the dots and light emitted from the primary source. The dots desirably are composed of an undoped semiconductor such as CdSe, and may optionally be overcoated to increase photoluminescence.

A preform is attached to a solid state light emitting die. One or more optical elements, such as a photoluminescent element, a refracting element, a filtering element, a scattering element, a diffusing element or a reflecting element, is included in and/or on the preform. For example, the preform may be a glass preform with phosphor particles suspended therein. The preform may be fabricated using microelectronic manufacturing techniques, and may be placed on the solid state light emitting die using pick and place techniques.

Exemplary systems and methods for obtaining information associated with at least one portion of a sample can be provided. For example, a first radiation can be received and at least one second radiation and at least one third radiation can be provided as a function of the first radiation. Respective intensities of the second and third radiations can be modulated, whereas the second and third radiations may have different modulation frequencies, and the modulated second and third radiations can be directed toward the portion. The photoluminescence radiation can be received from the portion based on the modulated second and third radiations to generate a resultant signal. The signal can be processed to obtain the information which is/are photoluminescence lifetime characteristics and/or a polarization anisotropy of the portion. According to another exemplary embodiment, the photoluminescence radiation can be received and the photoluminescence radiation may be based on wavelengths thereof.

A device for supporting chromophore elements suitable for emitting fluorescence in response to light excitation, the device comprising a substrate having a surface layer carrying the chromophore elements, forming a planar waveguide, and containing photoluminescent constituents which emit guided luminescence at the excitation wavelength(s) of the chromophore elements when they are excited by primary excitation light illuminating the surface layer. The invention is particularly applicable to biochip type devices.

A solar cell is disclosed to include a single crystal silicon chip, an electrode system, a glass plate cover, a polymer film set between the single crystal silicon chip and the glass plate cover, and a spectrum converter containing an inorganic phosphor, which absorbs radiation in purple, blue and green light of the Sun's solar radiation and converts the absorption into a photoluminescent light in yellow, orange-yellow and infrared area in the electromagnetic spectrum. The architecture characteristic of the solar cell increases the efficiency by about 20%.

The present invention provides new compositions containing colloidal nanocrystals with high photoluminescence quantum yields, new synthetic methods for the preparation of highly luminescent colloidal nanocrystals, as well as methods to control the photoluminescent properties of colloidal nanocrystals. The new synthetic methods disclosed herein allow photoemission brightness (quantum yield) to be correlated with certain adjustable nanocrystal growth parameters associated with a given synthetic scheme.

A color wheel comprises: a rotatable disc having a light reflective face and a region of photoluminescence material deposited on the light reflective face. The region of photoluminescence material comprises a substantially uniform thickness layer of a mixture of particles of the photoluminescence material that is deposited on the light reflective face of the disc by screen printing. The photoluminescence materials can comprise blue light or UV excitable photoluminescence materials such as phosphor materials or quantum dots. Color modulated light sources and a method of manufacturing a color wheel are also disclosed.

The present invention is a method for obtaining a better color rendering with a photoluminescence plate, and the better color rendering is obtained by using UV radiating on the photoluminescence plate stacked with a red photoluminescence plate, a green photoluminescence plate and a blue photoluminescence plate. Therefore, the color rendering is above 90% and close to the solar light. The photoluminescence plate can be made from directly coated with photoluminescence layers of three colors or with fully mixed fluorescent materials of three colors. Consequently, a white light relied on the present invention is more uniform than the conventional techniques with a color mixing performance based on tricolor LEDs.

A light emissive display having a specular waveguide that propagates short wavelength light and photoluminescent features adjacent to the waveguide that fluoresce, for example, in visible red, green, blue, and mixed colors when selectively coupled with the short wavelength light. The photoluminescent layers emit light primarily and, therefore, efficiently in the direction of an observer only. This light emissive display may be utilized as a planar light source, as patterned information signage, or as a re-configurable information display containing intensity modulated pixels. The light emissive display may be enhanced optically such that only a small portion of ambient light is reflected from the display while preserving the majority of emitted display luminance.