Apple Just Patented an Image Sensor with 20 Stops of Dynamic Range

Article note: Neat. It's leaning into the design space where you get a small sensel (For fill factor and resolution), and stacked dies mean you can pack quite a bit of readout circuity behind the photsensitive layer. Their sensel is basically a photodiode pumping a pair of (MOS) capacitors in vague-power-of-10 sizes attached, with a more sophisticated readout circuit that will separately read the charge on the diode junction capacitance and the caps to get three simultaneous ranges out of one sensel, for post-exposure auto-ranging. A little noise modeling on top and it's a good idea. We've got an undergrad in the lab I'm working in this summer working on a hand-made 4x4 LED array as a sensor to validate a different readout regime, but the same basic LED leakage charging the junction capacitance + noise model sensing mechanism.