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US 4,233,501 AGranted
Interference suppression for imaging optical systems
AssigneeRCA Corporation
InventorJohn A. Strother
Life of this patent
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AssigneeRCA Corporation
InventorJohn A. Strother
Estimating the term…
Apparatus for sun-interference suppression in optical imaging systems reduces the light flux density in the image of the sun in comparison to the light flux density of the scene image, thereby reducing the area of the scene image that is dominated by the sun. An illustrative reduction of 27:1 of the light flux density of the image of the sun compared to the light flux density of the image of the scene is accomplished by three filters formed of photochromic material positioned along the optical axis of the sun-interferences suppression apparatus behind an image-forming lens. The lens focuses the sunlight into a converging cone; the convergence of the cone of sunlight between photochromic filters provides intensification which enhances the darkening of subsequent photochromic filters. The positioning of the photochromic filters allows only the scene image within two (2) degrees of the center of the sun to be affected by the darkened photochromic glass.
An optical imaging apparatus for selectively reducing by a predetermined amount the flux density of radiation in the visible, near-ultraviolet and near-infrared portions of the electromagnetic spectrum from a relatively small very bright object within a larger scene that is less bright, comprising:
A method for selectively reducing by a predetermined amount the flux density of radiation in the visible, near-ultraviolet and near-infrared portions of the electromagnetic spectrum from a relatively small very bright object within a larger scene that is less bright, in an optical imaging apparatus having a lens with an exit pupil, radiation detecting means positioned at the image plane of said lens, comprising the steps of:
Dependencies are inferred from the claim text.