Abstract: Wavelength conversion elements formed from phosphors and dielectric interference particles dispersed in a host material, either in a single layer or in separate layers, are disclosed. Optical light conversion devices having such wavelength conversion elements, methods of making such wavelength conversion elements, and methods of using such wavelength conversion elements are also disclosed.

Abstract: An interference filter includes a layers stack comprising a plurality of layers of at least: layers of amorphous hydrogenated silicon with added nitrogen (a-Si:H,N) and layers of one or more dielectric materials, such as SiO2, SiOx, SiOxNy, a dielectric material with a higher refractive index in the range 1.9 to 2.7 inclusive, or so forth. The interference filter is designed to have a passband center wavelength in the range 750-1000 nm inclusive. Added nitrogen in the a-Si:H,N layers provides improved transmission in the passband without a large decrease in refractive index observed in a-Si:H with comparable transmission. Layers of a dielectric material with a higher refractive index in the range 1.9 to 2.7 inclusive provide a smaller angle shift compared with a similar interference filter using SiO2 as the low index layers.

Abstract: In a method of manufacturing a one-dimensionally varying optical filter, a substrate is coated to form a stack of layers of two or more different types. The coating may, for example, employ sputtering, electron-beam evaporation, or thermal evaporation. During the coating, the time-averaged deposition rate is varied along an optical gradient direction by generating reciprocation between a shadow mask and the substrate in a reciprocation direction that is transverse to the optical gradient direction. In some approaches, the shadow mask is periodic with a mask period defined along the direction of reciprocation, and the generated reciprocation has a stroke equal to or greater than the mask period along the direction of reciprocation. The substrate and the shadow mask may also be rotated together as a unit during the coating. Also disclosed are one-dimensionally varying optical filters, such as linear variable filters, made by such methods.

Abstract: An interference filter includes a layers stack comprising a plurality of layers of at least: layers of amorphous hydrogenated silicon with added nitrogen (a-Si:H,N) and layers of one or more dielectric materials, such as SiO2, SiOx, SiOxNy, a dielectric material with a higher refractive index in the range 1.9 to 2.7 inclusive, or so forth. The interference filter is designed to have a passband center wavelength in the range 750-1000 nm inclusive. Added nitrogen in the a-Si:H,N layers provides improved transmission in the passband without a large decrease in refractive index observed in a-Si:H with comparable transmission. Layers of a dielectric material with a higher refractive index in the range 1.9 to 2.7 inclusive provide a smaller angle shift compared with a similar interference filter using SiO2 as the low index layers.

Abstract: In a method of manufacturing a one-dimensionally varying optical filter, a substrate is coated to form a stack of layers of two or more different types. The coating may, for example, employ sputtering, electron-beam evaporation, or thermal evaporation. During the coating, the time-averaged deposition rate is varied along an optical gradient direction by generating reciprocation between a shadow mask and the substrate in a reciprocation direction that is transverse to the optical gradient direction. In some approaches, the shadow mask is periodic with a mask period defined along the direction of reciprocation, and the generated reciprocation has a stroke equal to or greater than the mask period along the direction of reciprocation. The substrate and the shadow mask may also be rotated together as a unit during the coating. Also disclosed are one-dimensionally varying optical filters, such as linear variable filters, made by such methods.

Abstract: Wavelength conversion elements formed from phosphors and dielectric interference particles dispersed in a host material, either in a single layer or in separate layers, are disclosed. Optical light conversion devices having such wavelength conversion elements, methods of making such wavelength conversion elements, and methods of using such wavelength conversion elements are also disclosed.

Abstract: Phosphor elements comprising phosphors in a host material having a phosphorescence-emitting surface with surface nanostructures are disclosed. Phosphor wheels having such phosphor elements, methods of making such phosphor elements, and methods of using such phosphor elements are also disclosed.

Abstract: In a method of manufacturing a one-dimensionally varying optical filter, a substrate is coated to form a stack of layers of two or more different types. The coating may, for example, employ sputtering, electron-beam evaporation, or thermal evaporation. During the coating, the time-averaged deposition rate is varied along an optical gradient direction by generating reciprocation between a shadow mask and the substrate in a reciprocation direction that is transverse to the optical gradient direction. In some approaches, the shadow mask is periodic with a mask period defined along the direction of reciprocation, and the generated reciprocation has a stroke equal to or greater than the mask period along the direction of reciprocation. The substrate and the shadow mask may also be rotated together as a unit during the coating. Also disclosed are one-dimensionally varying optical filters, such as linear variable filters, made by such methods.

Abstract: The present invention is directed to an electrophoretic fluid which comprises additive particles. The concentration of the additive particles in the electrophoretic fluid does not exceed 25% by weight and the additive particles are not seen at the viewing side during operation of the display. The resulting fluid can improve optical performance of a display device, such as image stability and contrast ratio. The present invention is also directed to an electrophoretic display comprising the electrophoretic fluid.

Abstract: A method for driving a display having a plurality of pixels, where each pixel is capable of displaying a first color or a second color and is sandwiched between a first electrode and a pixel electrode, the method including applying a driving sequence which includes: (a) for a first time period, applying a first voltage potential between the first electrode and each of the pixel electrodes of a first group of pixels, and applying no voltage potential between the first electrode and each of the pixel electrodes of a second group of pixels of the second color, thereby causing the display device to display an image of the first color with a background of the second color; and (b) for a second time period, applying no voltage potential between the first electrode and each of the pixel electrodes of the first group of pixels, and applying a second voltage potential to each of the pixel electrodes corresponding to the second group of pixels, to clear the onetime image created in step (a).

Abstract: Phosphor elements comprising phosphors in a host material having a phosphorescence-emitting surface with surface nanostructures are disclosed. Phosphor wheels having such phosphor elements, methods of making such phosphor elements, and methods of using such phosphor elements are also disclosed.

Abstract: In a method of manufacturing a one-dimensionally varying optical filter, a substrate is coated to form a stack of layers of two or more different types. The coating may, for example, employ sputtering, electron-beam evaporation, or thermal evaporation. During the coating, the time-averaged deposition rate is varied along an optical gradient direction by generating reciprocation between a shadow mask and the substrate in a reciprocation direction that is transverse to the optical gradient direction. In some approaches, the shadow mask is periodic with a mask period defined along the direction of reciprocation, and the generated reciprocation has a stroke equal to or greater than the mask period along the direction of reciprocation. The substrate and the shadow mask may also be rotated together as a unit during the coating. Also disclosed are one-dimensionally varying optical filters, such as linear variable filters, made by such methods.

Abstract: Phosphor elements comprising phosphors in a host material having a phosphorescence-emitting surface with surface nanostructures are disclosed. Phosphor wheels having such phosphor elements, methods of making such phosphor elements, and methods of using such phosphor elements are also disclosed.

Abstract: An interference filter includes a layers stack comprising a plurality of layers of at least: layers of amorphous hydrogenated silicon with added nitrogen (a-Si:H,N) and layers of one or more dielectric materials, such as SiO2, SiOx, SiOxNy, a dielectric material with a higher refractive index in the range 1.9 to 2.7 inclusive, or so forth. The interference filter is designed to have a passband center wavelength in the range 750-1000 nm inclusive. Added nitrogen in the a-Si:H,N layers provides improved transmission in the passband without a large decrease in refractive index observed in a-Si:H with comparable transmission. Layers of a dielectric material with a higher refractive index in the range 1.9 to 2.7 inclusive provide a smaller angle shift compared with a similar interference filter using SiO2 as the low index layers.

Abstract: The present invention is directed to an electrophoretic dispersion comprising charged pigment particles, in particular, an electrophoretic dispersion including both uncharged or lightly charged neutral buoyancy particles and uncharged or lightly charged additive particles. The combination improves the performance of an electrophoretic display, in particular the color state stability over time.

Abstract: A method for driving a display having a plurality of pixels, where each pixel is capable of displaying a first color or a second color and is sandwiched between a first electrode and a pixel electrode, the method including applying a driving sequence which includes: (a) for a first time period, applying a first voltage potential between the first electrode and each of the pixel electrodes of a first group of pixels, and applying no voltage potential between the first electrode and each of the pixel electrodes of a second group of pixels of the second color, thereby causing the display device to display an image of the first color with a background of the second color; and (b) for a second time period, applying no voltage potential between the first electrode and each of the pixel electrodes of the first group of pixels, and applying a second voltage potential to each of the pixel electrodes corresponding to the second group of pixels, to clear the onetime image created in step (a).

Abstract: The disclosure is directed toward driving methods and a driving circuit which are particularly suitable for bi-stable displays. In certain embodiments, methods provide the fastest and most pleasing appearance to the desired image while maintaining the optimal image quality over the life expectancy of an electrophoretic display device.

Abstract: An interference filter includes a layers stack comprising a plurality of layers of at least: layers of amorphous hydrogenated silicon with added nitrogen (a-Si:H,N) and layers of one or more dielectric materials, such as SiO2, SiOx, SiOxNy, a dielectric material with a higher refractive index in the range 1.9 to 2.7 inclusive, or so forth. The interference filter is designed to have a passband center wavelength in the range 750-1000 nm inclusive. Layers of a dielectric material with a higher refractive index in the range 1.9 to 2.7 inclusive provide a smaller angle shift compared with a similar interference filter using SiO2 as the low index layers.

Abstract: Devices and methods are disclosed for characterizing point flaws (including pinholes and point defects) of an optical filter. A passband test is performed, including: illuminating the optical filter with passband illumination whose spectral range at least overlaps a passband of the optical filter; acquiring a passband map of the optical filter using a two-dimensional array of photodetectors while illuminating the optical filter with the passband illumination; and identifying point defects of the optical filter as low intensity locations of the passband map. A stopband test is performed, including: illuminating the optical filter with stopband illumination whose spectral range lies entirely outside of the passband of the optical filter; acquiring a stopband map of the optical filter using the two-dimensional array of photodetectors while illuminating the optical filter with the stopband illumination; and identifying pinholes of the optical filter as high intensity locations of the stopband map.

Abstract: The present invention is directed to an electrophoretic dispersion comprising charged pigment particles, in particular, an electrophoretic dispersion including both uncharged or lightly charged neutral buoyancy particles and uncharged or lightly charged additive particles. The combination improves the performance of an electrophoretic display, in particular the color state stability over time.