US Patent 7830442 Compact economical lidar system

A lidar pulse is time resolved in ways that avoid costly, fragile, bulky, high-voltage vacuum devices—and also costly, awkward optical remappers or pushbroom layouts—to provide preferably 3D volumetric imaging from a single pulse, or full-3D volumetric movies. Delay lines or programmed circuits generate time-resolution sweep signals, ideally digital. Preferably, discrete 2D photodiode and transimpedance-amplifier arrays replace a continuous 1D streak-tube cathode. For each pixel a memory-element array forms range bins. An intermediate optical buffer with low, well-controlled capacitance avoids corruption of input signal by these memories.