Variable focal-length lens assembly
AssigneeThe Arizona Carbon Foil Company, Inc.
InventorJohn O. Stoner, Jr.
Life of this patent
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Abstract
Switchable optical devices are made of transparent optical elements having surfaces separated by small distances, typically less than a few hundred micrometers. The transparent elements contain roughness, kinoforms, Fresnel-lens, or other relief structures with predetermined optical properties that affect the passage of light through the optical elements by refraction and/or diffraction. By introducing a liquid with a refractive index matching that of the transparent elements' material into the space between the surfaces, the effects of the surface structures disappear almost completely, thereby changing the optical characteristics of the device. This effect is used advantageously to change the focal properties, scattering properties, or light directing properties of different kinds of optical devices.
Claims17
A switchable optical device comprising, in combination:
- (a) a first optical component having a first surface including a relief structure with predetermined optical properties that affect passage of electromagnetic radiation;
- (b) a second optical component having a second surface opposite to said first surface and separated by a gap;
- and
- (c) means for reversibly applying a film of fluid over said relief structure in the gap between the opposite surfaces;
- wherein the fluid and the relief structure have a substantially equal index of refraction, such that said optical properties are reversibly modified by the fluid when the fluid is applied over the relief structure.
A method for altering the passage of electromagnetic radiation in an optical device, comprising the following steps:
- (a) providing a first optical component having a first surface including a relief structure with predetermined optical properties that affect passage of electromagnetic radiation;
- (b) providing a second optical component having a second surface opposite to said first surface and separated by a gap;
- and
- (c) reversibly applying a film of fluid over said relief structure in the gap between the opposite surfaces, the fluid and the relief structure having a substantially equal index of refraction;
- whereby substantially cancelling said predetermined optical properties of the relief structure.
Dependencies are inferred from the claim text.