Polarization filter for autofocus pixel structures having symmetric apertures

An imaging system, comprising:

• an image sensor including a plurality of photodiodes arranged as a photodiode array, the plurality of photodiodes disposed on a substrate to form a plurality of polarization pixels, including:
• a symmetric polarization filter, comprising:
• a first polarizer defining a first plurality of apertures;
• and
• a second polarizer, adjacent with the first polarizer, defining a second plurality of apertures,
• wherein the first plurality of apertures is mirror symmetrical with the second plurality of apertures about a lateral axis of the symmetric polarization filter between the first polarizer and the second polarizer, wherein the lateral axis is defined as an axis of symmetry of the symmetric polarization filter, wherein the axis of symmetry is:
• in plane with the first polarizer and the second polarizer, and configured through a center point of the entire symmetric polarization filter,
• wherein the center point is configured at an equal distance from opposite edges of the symmetric polarization filter,
• and wherein the lateral axis is the axis of symmetry common to the mirror symmetry between the pluralities of apertures of the laterally adjacent polarizers across the axis of symmetry of the symmetric polarization filter for all polarizers of the filter.

An image sensor, comprising a plurality of image pixels, each image pixel comprising a plurality of subpixels and one or more groups of polarization pixels, wherein:

• the plurality of subpixels comprising at least one blue subpixel, at least one green subpixel, and at least one red subpixel,
• each subpixel of the plurality of subpixels being laterally or diagonally adjacent to one group of the one or more groups of polarization pixels, and
• each group of the one or more groups of polarization pixels comprises:
• a first polarization pixel and a second polarization pixel, and
• a symmetric polarization filter, comprising:
• a first polarizer defining a first plurality of apertures, the first polarizer being disposed over the first polarization pixel;
• and
• a second polarizer, laterally adjacent with the first polarizer, defining a second plurality of apertures, the second polarizer being disposed over the second polarization pixel,
• wherein the first plurality of apertures is mirror symmetrical with the second plurality of apertures about a lateral axis of the symmetric polarization filter between the first polarizer and the second polarizer, wherein the lateral axis is defined as an axis of symmetry of the symmetric polarization filter, wherein the axis of symmetry is in plane with the first polarizer and the second polarizer and is configured through a center point of the entire symmetric polarization filter, wherein the center point is configured at an equal distance from opposite edges of the symmetric polarization filter,
• and wherein the lateral axis is the axis of symmetry common to the mirror symmetry between the pluralities of apertures of the laterally adjacent polarizers across the axis of symmetry of the symmetric polarization filter for all polarizers of the filter.