Three-intensified-sensor color high-speed camera

In 1991, the authors developed a high-speed video camera with a frame rate of 4,500 pps, which was the world's fastest at that time and is currently marketed by a third party. An MCP-type image intensifier is attached directly to the image sensor to realize both very high light sensitivity and frame rate. Three intensified image sensors are combined with a cubic three-way beam splitter prism and three optical filter holders to form this high-speed video/ultra-high- speed triple-framing camera. The camera can capture fast- moving images under the following conditions: (1) 4,500-pps continuous color imaging with R, G & B filters and perfect synchronization of the three images for a full 256 X 256 X 3-pixel frame, or faster color imaging of up to 40,500 pps at a reduced resolution of 64 X 64 X 3 pixels. (2) Triple-speed continuous monochrome imaging without filters and delayed synchronization, i.e. 13,500 pps for a full 256 X 256-pixel frame or up to 121,500 pps for a reduced 64 X 64-pixel frame. (3) Ultra-fast three-frame capture at a speed of 1/50,000,000 s by delayed gating of the image intensifiers. The cubic prism is also convertible, enabling simultaneous image capture by three monochromatic light sources of different wavelengths with no loss of incident light energy. This is in contrast with the large energy loss caused by a cubic prism using metalized half-mirrors, which reduced light transmission to one quarter, coupled with the losses associated with the three optical filters, reducing the light energy incident on each individual sensor still further.