Evolution of Ultra-High-Speed CCD Imagers

This paper reviews the high-speed video cameras developed by the authors. A video camera operating at 4,500 frames per second (fps) was developed in 1991. The partial and parallel readout scheme combined with fully digital memory with overwriting function enabled the world fastest imaging at the time. The basic configuration of the camera later became a de facto standard of high-speed video cameras. A video camera mounting an innovative image sensor achieved 1,000,000 fps in 2001. In-situ storage with more than 100 CCD memory elements is installed in each pixel of the sensor, which is capable of recording image signals in all pixels in parallel. Therefore, the sensor was named ISIS, the in-situ storage image sensor. The ultimate parallel recording operation promises the theoretical maximum frame rate. A sequence of more than one hundred consecutive images reproduces a smoothly moving image at 10 fps for more than 10 seconds. Currently, an image sensor with ultrahigh sensitivity is being developed in addition to the ultra-high frame rate, named PC-ISIS, the photon-counting ISIS, for microscopic biological observation. Some other technologies supporting the ultra-high-speed imaging developed are also presented.