Compact panoramic camera: optical system, apparatus, image forming method

Abstract

An optical system, apparatus, and method for sensing 360-degree horizontal and wide vertical field of view are shown. Powerful optics creates high resolution decompressed images on an image sensor. The compact panoramic camera includes two major optical components: (i) an axially symmetric convex aspheric reflector incorporated into a catadioptric optical element capable of providing a virtual curved image of a 360-degree panoramic scene with a specific image compression and (ii) a decompression lens with hardware aperture. The decompression lens is comprised of three single lens elements and accepts the virtual curved and compressed image and projects it onto the image sensor with high optical resolution and desirable image decompression to achieve a high digital resolution at the same time. Another version of decompression lens is comprised only of a single lens element and projects high resolution decompressed images onto an image sensor.

What is claimed is: 
     
         1 . A system for a compact panoramic camera having an image sensor, comprising:
 a convex reflector having an axially symmetric aspheric surface that provides a virtual curved and compressed image of a panoramic scene with a non-parabolic image compression; and   a decompression lens positioned to receive the virtual curved and compressed image, the decompression lens configured to:
 decompress the virtual curved and compressed image into a real image with a high optical resolution and a parabolic image decompression; and 
 project the real image onto the image sensor. 
   
     
     
         2 . The system of  claim 1 , wherein the axially symmetric aspheric surface of the convex reflector is of a hyperbolic structure. 
     
     
         3 . The system of  claim 1 , wherein the non-parabolic image compression of the virtual curved and compressed image is in the same format as the structure of the axially symmetric aspheric surface. 
     
     
         4 . The system of  claim 1 , wherein the high optical resolution includes the system having a polychromatic diffraction modulation transfer function of 30% or more for 150 cy/mm. 
     
     
         5 . The system of  claim 1 , further comprising a catadioptric optical element configured to create the virtual curved and compressed image, wherein the catadioptric optical element includes the convex reflector. 
     
     
         6 . The system of  claim 5 , wherein the catadioptric optical element further includes a first refractive surface positioned to receive light rays from the panoramic scene and a second refractive surface positioned to receive light rays reflected by the convex reflector. 
     
     
         7 . The system of  claim 1 , wherein the decompression lens is comprised of one or more lens elements having a total of one or more aspheric surfaces. 
     
     
         8 . The system of  claim 7 , wherein at least one of the one or more aspheric surfaces has a diffractive optical structure disposed along the at least one of the one or more aspheric surfaces. 
     
     
         9 . The system of  claim 7 , wherein the decompression lens includes a first negative lens element having a negative optical power, a second negative lens element having a negative optical power, and a positive lens element having a positive optical power and positioned between the first negative lens element and the second negative lens element. 
     
     
         10 . The system of  claim 9 , wherein a first surface of the first negative lens element is coated with a thin film coating capable of cutting off infrared radiation starting from approximately 680 nanometers and up. 
     
     
         11 . The system of  claim 9 , wherein at least one of the first negative lens element, the second negative lens element, and the positive lens element have one or more aspheric surfaces. 
     
     
         12 . The system of  claim 1 , further comprising a hardware aperture configured to filter out light rays other than those reflected directly from the convex reflector, wherein the hardware aperture is positioned a distance from the convex reflector at or in a vicinity of a geometrical focus of the convex reflector, and wherein the decompression lens is positioned to receive the virtual curved and compressed image filtered by the hardware aperture. 
     
     
         13 . A method for compressing and decompressing an image with high resolution, comprising:
 receiving, by a catadioptric optical element, light ray bundles from a scene;   compressing, by the catadioptric optical element, the light ray bundles into a virtual curved and compressed image with a non-parabolic compression;   reflecting, by the catadioptric optical element, the virtual curved and compressed image onto a hardware aperture;   filtering out, by the hardware aperture, light rays other than those reflected by the catadioptric optical element;   receiving, by a decompression lens, the virtual curved and compressed image from the hardware aperture;   decompressing, by the decompression lens, the virtual curved and compressed image into a real image; and   projecting, by the decompression lens, the real image onto an image sensor.   
     
     
         14 . The method of  claim 13 , wherein the non-parabolic compression of the virtual curved and compressed image is of a hyperbolic structure, and wherein the real image is in a parabolic decompression format with a high optical resolution. 
     
     
         15 . The method of  claim 13 , wherein the method for compressing and decompressing the light ray bundles is done by optic means without digital image processing. 
     
     
         16 . A decompression lens for use with a non-parabolic mirror and an image sensor in a catadioptric optical system, comprising:
 at least one lens element positioned to receive a virtual curved and compressed image in a non-parabolic compression format from the non-parabolic mirror;   wherein the at least one lens element is configured to decompress the virtual curved and compressed image into a real image with a high optical resolution and a parabolic type of decompression, and project the real image onto the image sensor.   
     
     
         17 . The decompression lens of  claim 16 , wherein the at least one lens element includes a first negative lens element that has at least one aspheric surface, the first negative lens element structured to at least one of have a negative optical power, expand bundles of light rays, and partially correct field aberrations using the at least one aspheric surface. 
     
     
         18 . The decompression lens of  claim 17 , wherein the at least one lens element includes a second negative lens element that has aspheric surfaces and is positioned in close proximity to the image sensor, the second negative lens element is structured to at least one of have a negative optical power, correct image compression, correct field curvature, and correct residual field aberrations using the aspheric surfaces. 
     
     
         19 . The decompression lens of  claim 18 , wherein the at least one lens element includes a positive lens element that has aspheric surfaces, wherein the positive lens element is structured to at least one of have a positive optical power, converge bundles of light rays, and partially correct field aberrations by using the aspheric surfaces, and wherein the positive lens element positioned between the first negative lens element and the second negative lens element. 
     
     
         20 . The decompression lens of  claim 19 , wherein the first negative lens element and the second negative lens element are made from high dispersion plastic materials including at least one of Polystyrene, Polycarbonate, and Rexolite, and wherein the positive lens element is made from low dispersion optical plastic materials including at least one of Acrylic, PMMA, and Zeonex.