Masked pixel arrays
An optical sensor includes an array of pixels configured to convert photons into electrons for forming an image or to measure spectral content without forming an image. A filter assembly is operatively associated with the array of pixels for passing predetermined bandwidths of photons to the array of pixels. A mask is operatively associated with the array of pixels and the filter assembly. The mask includes a plurality of apertures each for limiting photons passing through the filter assembly to a respective pixel in the array of pixels.
1. An optical sensor comprising:
an array of pixels configured to convert photons into electrons for forming an image;
a filter assembly operatively associated with the array of pixels for passing predetermined bandwidths of photons to the array of pixels; and
a mask operatively associated with the array of pixels and the filter assembly, wherein the mask includes a plurality of apertures each for limiting photons passing through the filter assembly to a respective pixel in the array of pixels,
wherein the filter assembly includes at least one SWIR filter for passing SWIR photons to a respective pixel in the array of pixels,
wherein one of the apertures limits photons passing through the SWIR filter and has dimensions such that signal to noise ratio for the respective pixel is the same as the other pixels on the array of pixels to within 30%,
wherein the filter assembly includes at least one filter for passing visible light photons to the array of pixels,
wherein one of the apertures limits photons passing through the visible light filter and has dimensions such that signal to noise ratio for the respective pixel is the same as the other pixels on the array of pixels to within 30%,
wherein the filter assembly includes at least one filter for passing NIR photons to the array of pixels,
wherein one of the apertures limits photons passing through the NIR filter and has dimensions of such that signal to noise ratio for the respective pixel is the same as the other pixels on the array of pixels to within 30%, and
wherein the array of pixels includes four pixels, wherein the filter assembly includes a SWIR filter for passing SWIR photons to a first one of the four pixels, a NIR filter for passing NIR photons to a second one of the four pixels, a red filter for passing red photons to a third one of the four pixels, and a green filter for passing green photons to a fourth one of the four pixels.
2. An optical sensor as recited in claim 1 , wherein the four pixels are arranged in a two by two pixel array, wherein the red and green pixels are diagonal from one another across the array.
3. An optical sensor as recited in claim 1 , wherein the array of pixels includes five pixels, wherein the filter assembly includes a SWIR filter for passing SWIR photons to a first one of the five pixels, a NIR filter for passing NIR photons to a second one of the five pixels, a red filter for passing red photons to a third one of the five pixels, a green filter for passing green photons to a fourth one of the five pixels, and a blue filter for passing blue photons to a fifth one of the five pixels.
4. An optical sensor as recited in claim 3 , wherein the SWIR filter, NIR filter, red filter, green filter, and blue filter are aligned in a row with one another.