Omnivision Proposes Dual-PD-Size Dual-Exposure Pixel

Omnivision's patent application US20140246561 "High dynamic range pixel having a plurality of photodiodes with a single implant" by Gang Chen, Dajiang Yang, Jin Li, Duli Mao, Hsin-Chih Tai proposes a dual-PD-size pixel where each PD exposure can be independently controlled. This approach is known, "however, one challenge with manufacturing HDR image sensors using this approach is that additional photo masking and implantation steps are required during manufacture, which add to the overall complexity and cost of implementing the HDR image sensors." So, Omnivision proposes to use the same PD implant and masking layer:

Some other possibilities of the large PD implant layouts: