A 256×256 14k range maps/s 3-D range-finding image sensor using row-parallel embedded binary

Abstract

These days, 3-D information technology is being developed rapidly and has been applied to various fields. Moreover, ultra-fast 3-D range-finding makes way for the possibilities of additional applications such as drop tests, observation of a high-speed moving target, and automated controls in robot vision. While 3-D range-finding image sensors using time-of-flight (TOF) don't achieve high-speed 3-D range finding [1,2], several high-speed and high-accuracy 3-D range-finding image sensors employing the light-section method have been reported [3–6]. Column-parallel search of a pixel activated by the reflection of a projected sheet beam is repeated the same number of times as the number of rows [3,4]. Row-parallel search of an activated pixel in each row at the same time is suitable for the light-section method when the light-section method uses a sheet beam as a horizontal scanner. Previous work [5,6] employs row-parallel search and realizes high-speed detection of the pixel; however, the methods require long address encoding paths and additional clock cycles (O(log N), N: the # of pixels in a row) whenever they acquire column addresses of detected pixels.