Stacking layers of silicon is all the rage these days, and Sony is getting in on the party with a new image sensor for smartphones at the ISSCC conference. The company is using 3D fabrication to layer a 125MB DRAM cache in between a conventional backside-illuminated image sensor and the accompanying processing circuitry. That DRAM buffer solves some annoying problems with smartphone image capture and lets the sensor capture more frames per second of slow-motion video.
Those who have already used a device with an electronic shutter will be familiar with the "rolling shutter" effect, wherein the line-by-line readout of data from the sensor causes fast-moving objects to appear tilted or otherwise distorted. Sony says the DRAM buffer built into this sensor can read out the entire 19.3MP raw image in 1/120 of a second. That's four times faster than the company's own IMX318 sensor, and it does appear to have a major positive effect on action photos.
Putting a DRAM cache in close proximity to the sensor also lets the device capture slow-motion 1920×1080 video at up to 1000 frames per second. Most of today's phones can only capture 1920×1080 slow motion at around 120 FPS, so that improvement could offer a whole new window into fast action. The company demonstrated this new sensor's prowess with an impressive demo reel:
Sony didn't offer any information on commercial implementations of this technology, but given the popularity of its Exmor image sensors in high-end smartphones, we'd expect handsets with much-improved action and slow-mo capture to begin appearing on the market relatively soon.