Directional diffuser
AssigneeAztec Systems, Inc.
InventorsJames Cowan, Kenneth A. Haines
Life of this patent
Estimating the term…
Abstract
A diffuser is disclosed which transmits or reflects incident light into a specific range of angles. In a preferred embodiment, this light is uniformly scattered throughout a cone of angles. The diffuser consists of two parts. The first part diffracts or reflects light into a specific offset angle. The second part, in the preferred embodiment, uniformly scatters the light through a range of angles, which is centered on the offset angle. The diffusers have utility in applications such as screens for wrist watches, computers, calculators, and cell phones.
Claims3
A method for making a directional reflector for reflecting an amount of incident light, the directional reflector having a reflective surface, wherein the reflective surface has a periodicity on the order of a wavelength of the incident light and wherein the reflective surface further includes a coarse periodicity having an asymmetrical blazed profile and a fine periodicity, comprising the steps of:
- creating the coarse periodicity having an asymmetrical blazed profile by prism coupling and recording into a layer of photoresist using more than one beam, wherein each beam is separated by a small angle and wherein each beam is incident at a large oblique angle;
- and
- creating the fine periodicity by reflecting a single beam from the layer of photoresist using prism coupling.
A method for obtaining white light using a directional reflector having a reflective surface, wherein the reflective surface has a periodicity on the order of a wavelength of incident light and wherein the reflective surface further includes a coarse periodicity having an asymmetrical blazed profile and a fine periodicity, comprising the steps of:
- creating the coarse periodicity having an asymmetrical blazed profile by prism coupling and recording into a layer of photoresist using more than one beam, wherein each beam is separated by a small angle and wherein each beam is incident at a large oblique angle;
- creating the fine periodicity by reflecting a single beam from the layer of photoresist using prism coupling;
- and
- recording the fine periodicity in adjacent narrow parallel stripes, wherein each stripe reflects a different color.
Dependencies are inferred from the claim text.