Scanning Light Field Camera

Abstract

A light field camera device comprising an array of light field camera elements, each camera element comprising: a scanner for scanning an input beam across a two-dimensional angular field; an input focus modulator for modulating the focus of the input beam; a radiance sensor for sensing the radiance of the input beam over time; and a radiance sampler for sampling the radiance of the input beam at discrete times.

1 . A light field camera device comprising an array of light field camera elements populating a camera surface, each camera element comprising:
 (a) a scanner for scanning an input beam across a two-dimensional angular field;   (b) an input focus modulator for modulating the focus of the input beam over time;   (c) a radiance sensor for sensing the radiance of the input beam over time; and   (d) a radiance sampler for sampling the radiance of the input beam at discrete times.   
     
     
         2 . The device of  claim 1 , wherein the scanner is selected from the group comprising: an electromechanical scanning mirror; an addressable deflector stack; an acousto-optic scanner; and an electro-optic scanner. 
     
     
         3 . The device of  claim 1 , wherein the scanner comprises a biaxial electromechanical scanning mirror with at least one drive mechanism selected from the group comprising: an electrostatic drive mechanism; a magnetic drive mechanism; and a capacitive drive mechanism. 
     
     
         4 . The device of  claim 1 , wherein the scanner comprises a first scanner for scanning the input beam in a first direction and a second scanner for simultaneously scanning the input beam in a second direction, the second direction substantially orthogonal to the first. 
     
     
         5 . The device of  claim 4 , wherein the first and second scanners are selected from the group comprising: an electromechanical scanning mirror; an addressable deflector stack; an acousto-optic scanner; and an electro-optic scanner. 
     
     
         6 . The device of  claim 1 , wherein the input focus modulator is selected from the group comprising: a liquid crystal lens; a liquid lens; a deformable membrane mirror; a deformable-membrane liquid-filled lens; an addressable lens stack; and an electro-optic lens. 
     
     
         7 . The device of  claim 1 , wherein the radiance sensor is selected from the group comprising: a monochromatic radiance sensor; and a polychromatic radiance sensor. 
     
     
         8 . The device of  claim 1 , wherein the radiance sensor comprises at least one photodetector selected from the group comprising: a photodiode operating in photoconductive mode; a photodiode operating in photovoltaic mode; a phototransistor; and a photoresistor. 
     
     
         9 . The device of  claim 1 , wherein the radiance sensor comprises a plurality of photodetectors, each photodetector adapted to have a different spectral response. 
     
     
         10 . The device of  claim 1 , wherein the radiance sampler comprises at least one analog-to-digital converter (ADC). 
     
     
         11 . The device of  claim 1 , wherein the radiance sampler comprises at least one programmable gain amplifier (PGA). 
     
     
         12 . The device of  claim 1 , further comprising at least one actuator for oscillating the camera surface between at least two positions. 
     
     
         13 . The device of  claim 12 , wherein the oscillation is resonant. 
     
     
         14 . A method for capturing a light field, the method comprising, for each of a set of positions on a camera surface, the steps of:
 (a) scanning an input beam across a two-dimensional angular field;   (b) modulating the focus of the input beam over time;   (c) sensing the radiance of the input beam over time; and   (d) sampling the radiance of the input beam at discrete times.   
     
     
         15 . The method of  claim 14 , wherein the focus-modulating step comprises modulating the focus of the input beam in accordance with a specified depth value corresponding to the position on the camera surface and the instantaneous direction of the scanned input beam within the angular field. 
     
     
         16 . The method of  claim 15 , wherein the specified depth is selected from the group comprising: a scene depth; and a fixation depth of a viewer. 
     
     
         17 . The method of  claim 14 , further comprising oscillating the camera surface between at least two positions.