Image sensor using single photon jots and processor to create pixels

1. An imaging system comprising:

an imaging array comprising a plurality of binary pixels, each binary pixel responding to photons in a first wavelength band that impinge substantially only upon an area on the imaging array smaller than a 3.7 μm airy disk diameter, each binary pixel configured for controllable reset and selective readout, and configured to provide, upon readout, a single-bit binary sample indicative of whether at least a threshold number of charge carriers have been collected by that binary pixel since that binary pixel was last reset; and

a readout circuit in electrical communication with the imaging array and configured to facilitate the formation of an image having a plurality of multilevel digital samples corresponding to the first wavelength band by operating the reset and readout of the binary pixels to produce, for use in formation of the image, at least forty binary samples corresponding to each of the multilevel digital samples and all read out from an area on the imaging array smaller than the 3.7 μm air disk diameter, the forty binary samples corresponding to each of the multilevel digital samples comprising a plurality of temporal samplings of one or more of the binary pixels.

2. The imaging system as recited in claim 1 , wherein the at least forty binary samples corresponding to one of the multilevel digital samples are sampled from a selected one of the binary pixels.

3. The imaging system as recited in claim 1 , wherein the at least forty binary samples corresponding to one of the multilevel digital samples are sampled from at least forty different binary pixels in a neighborhood.

4. The imaging system as recited in claim 1 , wherein at least two of the plurality of multilevel digital samples are formed based on different numbers of binary samples, and wherein all of the binary pixels contributing to each of the two multilevel digital samples are fully operational.

5. The imaging system as recited in claim 1 , wherein the number of binary samples used to form each of the multilevel digital samples is variable.

6. The imaging system as recited in claim 1 , wherein the threshold number of charge carriers is representative of a single photon of light received by one of the binary pixels.

7. The imaging system as recited in claim 1 , wherein each binary pixel can be read out as a logical “1” or a logical “0”, depending upon whether or not at least one photon has been received by the binary pixel.

8. The imaging system as recited in claim 1 , wherein the imaging array comprises color filters corresponding to the first wavelength band and covering a plurality of the binary pixels so as to facilitate color imaging therewith, the imaging array further comprising a second plurality of binary pixels, and second color filters corresponding to the second wavelength band of interest and covering the second plurality of binary pixels.

9. The imaging system as recited in claim 1 , further comprising a digital processor configured to generate the image, wherein the digital processor is integrated on the same chip as the imaging array.

10. The imaging system as recited in claim 1 , further comprising a processor configured to use an algorithm to form the image from a binary pixel pattern, wherein the algorithm is dynamically varied so as to trade spatial resolution for light sensitivity.

11. The imaging system as recited in claim 1 , further comprising a processor configured to use plural readouts of the imaging array to form a single image.

12. The imaging system as recited in claim 1 wherein the binary pixels each comprise an integrating silicon photodetector, an amplifier, a reset circuit, and a selection switch for reading out the binary pixel.

13. The imaging system as recited in claim 1 , wherein the imaging array is made using a CMOS-compatible process.

14. The imaging system as recited in claim 1 , wherein each of the binary pixels occupies a total area of the imaging array surface that is less than 1 square micron.

15. The imaging system as recited in claim 1 , wherein the threshold number of charge carriers for each binary pixel corresponds to receiving a number of photons greater than one.

16. The imaging system as recited in claim 1 , wherein for the at least forty binary samples corresponding to a first one of the multilevel digital sample, a fraction, D, of the at least forty binary samples indicate that a threshold number of charge carriers have been collected, and the light in the first wavelength band impinging upon the one or more binary pixels used to collect the at least forty binary samples at the time those binary pixels are exposed for the respective readouts forming the at least forty binary samples exhibits an intensity, H, and the binary samples exhibit a D versus log H exposure characteristic.

17. The imaging system as recited in claim 1 , wherein the readout circuit provides the binary samples to a memory for storage.