At the 2016 IEEE International Electron Devices Meeting 03 Dec – 07 Dec 2016, Canon will be discussing their breakthrough Temporal Noise Over 90dB Dynamic Range 4k2k Super 35mm Format Seamless Global Shutter CMOS Image Sensor with Multiple-Accumulation Shutter Technology.
Large-Format CMOS Imager with Global Shutter for High-Performance Cameras:
Canon researchers will discuss high-resolution, large-format CMOS imaging technology for use in high-performance cameras large enough to take photographs and videos at ultra-high-definition resolution.
Most CMOS imagers use a rolling shutter, which captures an image at slightly different times at different areas of the imager. This can lead to image artifacts, especially for moving targets, because the image is taken while the subject is in different positions in the field. Imagers with global shutters capture light from each pixel in the imager at the same time, eliminating these artifacts. However, a global shutter usually leads to less dynamic range and higher noise and dark current, and thus to inferior photographs.
The Canon researchers developed a new architecture that enables the readouts of multiple pixels to be accumulated and stored in memory, and then processed all at once. This technique enabled the implementation of a global shutter while also delivering excellent noise and dark current performance and high dynamic range (92dB at a standard 30fps frame rate).
The images of a vibrating ukulele were taken at the same shutter speed (1/5000 sec.). In the global shutter mode (a) distortion is successfully suppressed, while (b) shows distortion from a rolling shutter. The bottom images show the difference between (a) quadruple charge accumulation with the global shutter and (b) single charge accumulation, both at a 1/90 sec. shutter speed.
(Paper #8.6, “A 1.8e- Temporal Noise Over 90dB Dynamic Range 4k2k Super 35mm Format Seamless Global Shutter CMOS Image Sensor with Multiple-Accumulation Shutter Technology,” K. Kawabata et al, Canon, Inc.)