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US 7,127,141 B2Granted
Non-imaging optical corner turner
AssigneeNellcor Puritan Bennett LLC
InventorMichael E. Fein
Life of this patent
Estimating the term…
Abstract
The present invention provides a device and method to efficiently turn light from an optical fiber around a corner while avoiding the frustrated-TIR loss that would occur if the fiber were bent. The invention uses non-imaging optics which efficiently deal with beam divergence half-angles less than 90°. By recognizing that most light from a fiber optic source will have a divergence half-angle of less than 90 degrees, a practical solution is achieved using non-imaging optics.
Claims10
An apparatus for deflecting light from an optical fiber around a corner, comprising:
- a light guide configured to transmit light;
- a corner turning optical structure coupled to the light guide at an interface, wherein the corner turning optical structure includes a surface angled with respect to the interface such that axial light rays that pass through the interface from the light guide are reflected by the surface into a window of the corner turning optical structure at an angle substantially normal to the window, and wherein the interface is configured for total internal reflection of light rays which strike the interface from the corner turner at an angle of incidence that is greater than a defined critical angle, wherein the critical angle is 69 degrees or more.
An apparatus for deflecting light around a corner, comprising:
- an optical light guide configured to transmit a beam of light at a maximum divergence half-angle less than 90 degrees;
- and
- an optical corner-turning structure adjoining the optical light guide to form an interface, wherein the corner-turning structure is adapted to reflect axial light from the optical light guide off of a surface of the corner-turning structure, the surface arranged to direct the axial light into a window of the optical corner-turning structure at a substantially normal incidence to the window, wherein the surface is configured to reflect light entering the corner-turning structure from the interface at an angle that is a defined degree away from normal to the interface back toward the interface, and wherein the interface is configured for total internal reflection of light striking the interface from within the corner-turning structure at an angle greater than a defined critical angle, wherein the critical angle is 69 degrees or greater.
Dependencies are inferred from the claim text.