Synchronized rotating prism and CCD electrical readout color camera

Abstract

A video camera system combining a charge coupled device (CCD) with a rotating prism optical element is disclosed. The rotating prism optical element moves an optical image on the transducer surface of the CCD array in precise synchronism with a CCD array clock which is transferring charge between transducer sites of the array. Since charge transfer occurs in synchronism with image movement, the exposure of transducer sites to image blurring or smearing additional optical energy is eliminated. The disclosed apparatus is particularly useful for high-speed, high-resolution, military, possibly airborne, camera systems. The invention also contemplates resolution of color images, with the use of color selective filters over adjacent columns of the CCD imaging array. The invention additionally contemplates utilizing a rotating prism optical element with other types of detectors.

What is claimed is: 
     
       1. The method for producing electrical signals representing an optical input image comprising the steps of: focusing said optical input image onto a photosensitive retina of a charge coupled device array, said photosensitive retina comprising a plurality of columns of optical to electrical signal transducer sites;   moving said focused image along a lengthwise total dimension of said columns of transducer sites toward an electrical signal readout site portion for each said column, said moving step including rotating homogeneous optical prism deflecting of said focused image between successive transducer sites from a first site to said readout site in each of said columns;   transferring translated optical signal generated quantums of electrical charge, representing pixels of said optical input image, between illuminated lengthwise adjacent transducer sites in said columns, said transferring progressing toward said electrical signal readout site in synchronism with said image moving;   reading said electrical signals from said readout sites in each said column in predetermined order; and   processing said readout electrical signals into a predetermined output signal format.   
     
     
       2. The method of claim 1 wherein said transferring step includes generating a transducer site to transducer site transferring clock signal in response to sensed instantaneous positions of said rotating optical prism. 
     
     
       3. The method of claim 2 wherein said reading step includes shifting said electrical charge signals from said electrical signal readout sites located in a plurality of said columns in a shifting clock accessed serial group of signal charge packets. 
     
     
       4. The method of claim 3 further including the steps of: reading electrical signal from a final transducer site in each said column in a row organized readout; and   optically shielding said final transducer sites from row readout attending additional optical signal input smearing.   
     
     
       5. The method of claim 4 wherein said focusing step also includes transmitting said optical input image through a plurality of color selective filters disposed over predetermined columns of sites in said photosensitive portion. 
     
     
       6. The method of claim 4 wherein said focusing step includes transmitting said optical input image through an optical beamsplitter element and an adjacent color selective filter. 
     
     
       7. Video camera apparatus comprising the combination of: a charge coupled device semiconductor array having a plurality of predetermined orientation aligned columns of optical photon to electrical charge signal transducing pixel points dispersed over an image reception surface portion thereof;   optical means for focusing a camera input optical image on an image reception surface portion of said charge coupled device semiconductor array;   optical displacement means located intermediate said optical means for focusing and said image reception surface for moving said focused camera input optical image along the lengthwise extent of said column pixel points and toward a predetermined electrical signal readout location therein;   electrical shifting means synchronized with said optical displacement means for transferring electrical charge signals representing said camera input optical image between illuminated successive pixel points in each said column of said image reception surface toward said predetermined electrical signal readout location; and   means for communicating said column charge signals from said readout location into a video signal utilizing apparatus.   
     
     
       8. The video camera apparatus of claim 7 wherein said optical displacement means comprises a homogeneous optical prism rotating about a cross sectional centroid thereof. 
     
     
       9. The video camera apparatus of claim 8 wherein said optical prism is rotated at a predetermined fixed rate of revolution. 
     
     
       10. The video camera apparatus of claim 9 wherein said electrical shifting means includes electrical clock pulse signal generator means for generating a shifting clock signal synchronized with said optical prism movement. 
     
     
       11. The video camera apparatus of claim 10 further including means for determining said rate of revolution and said shifting clock rate in response to a selected image frame rate. 
     
     
       12. The video camera apparatus of claim 7 further including optical filtering means of predetermined color signal response characteristics for segregating optical signals received in adjacent columns of said pixel points according to color. 
     
     
       13. The video camera apparatus of claim 7 further including a charge signal storage pixel location for each said column of pixel points and wherein said charge signal storage pixel location for each said column comprises an additional of said pixel points located in each said column of pixel points and shielded from smear generating optical signal input energy in a row readout sequence. 
     
     
       14. The video camera apparatus of claim 7 wherein: said optical means for focusing includes optical lens means for focusing said optical image through said optical prism onto said image reception surface; and   said charge coupled device is a full frame charge coupled device.   
     
     
       15. Video camera apparatus comprising the combination of: a semiconductor detector member having a parallel columns of elements disposed optical photon to electrical signal transducing image reception surface;   optical means for focusing a camera input optical image on said detector member image reception surface;   rotationally driven homogeneous prism optical image displacement means located intermediate said optical means for focusing and said image reception surface for continuously moving said focused camera input optical image over column lengths of said image reception surface toward a predetermined region of electrical readout located therein; and   means for transferring, in synchronism with said image moving, an electrical signal responsive to successive portions of said optical image into successive later scanned column portions of said detector member and thence into a video signal utilizing apparatus.   
     
     
       16. The camera apparatus of claim 15 wherein: said detector member column elements comprise a plurality of optical photon to electrical charge signal transducing pixel points; and   said homogeneous prism optical image moving includes electrical signal charge readout during illumination of said transducing pixel points by said focused camera input optical image.   
     
     
       17. The camera apparatus of claim 15 wherein said detector member comprises a surface acoustic wave device having an optical photon to electric charge conversion characteristic.