Cameras with on-chip memory CMOS image sensors

In this article we give an overview of ultra high-speed (UHS) CMOS image sensors with on-chip analog memories placed on the periphery of pixel array and high speed cameras with the UHS CMOS image sensors for the visualization of UHS phenomena. The developed image sensors consist of 400^H × 256^V pixels and 128 memories/pixel, and the readout speed of 1 T pixel/s is obtained, leading to 10 Mfps full resolution video capturing with consecutive 128 frames, and 20 Mfps half resolution video capturing with consecutive 256 frames. The first development chip was employed in the high-speed video camera and put in practical use in 2012. By the development of dedicated process technologies, photosensitivity improvement and power consumption reduction were simultaneously achieved, and the performance- improved chip has been utilized in the commercialized high-speed video camera since 2015 offering 10 Mfps with ISO 16000 photosensitivity. Due to the improved photosensitivity, clear images can be captured and analyzed even under low light condition, such as under a microscope, and capturing of UHS light emission phenomena.