Directional diffuser
OwnerJames Cowan, Kenneth A. Hainesinventors
Life of this patent
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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.
Claims12
A directional reflector having a surface, the surface comprising:
- a first periodic surface component having a periodic wedge-shape, the periodic wedge-shape having a first period, and
- a second periodic surface component having a second period,
- wherein the combination of the first periodic surface component and the second periodic surface component causes an oblique light ray, which is incident on the surface, to be reflected or transmitted throughout a range of angles.
An apparatus having a surface, the surface having periodic surface elements comprising:
- a first surface component in a first surface direction comprising two contiguous pieces, wherein a first surface piece is described by a parabolic function, and the second surface piece is described by an identical but inverted parabolic function;
- a second surface component in a second surface direction, the second surface direction being orthogonal to the first surface direction, comprising two contiguous pieces wherein a third surface piece is described by an offset parabolic function, and a fourth surface piece is described by an identical but inverted offset parabolic function thereby creating a surface which is capable of transmitting or reflecting oblique incident light into a bundle of rays which are uniformly distributed about a normal to its surface.
Dependencies are inferred from the claim text.