Patent ID: 7230685
Filing Date: 2007-06-12
Classification: G01C,G01S,H01L

Abstract:
1. An apparatus for generating range-image-data, the apparatus comprising: a light-emitting means for emitting pulsed light within a preset measuring range, the pulsed light having a rise period, a flat period, and a fall period; an imaging means for photographing an object existing in the measuring range, the imaging means including a photosensor comprised of a two-dimensional array of charge integration type photoelectric conversion elements, the photosensor adapted to be exposed adjustably; an image-data-obtaining means for obtaining image data by controlling the emission period or the emission-start timing for the light-emitting means and the exposure period or the exposure-start timing for the imaging means, the image data being such that a value of each pixel is the output from one of the photoelectric conversion elements; a range-image-data-generating means for generating range-image-data based on the obtained image data, the range-image-data comprised of pixels, each having a pixel value according to the distance to the photographed object; the image-data-obtaining means including a first image-data-obtaining means for obtaining first image data from the imaging means by causing the imaging means to make an exposure, without causing the light-emitting means to emit pulsed light; the image-data-obtaining means further including a second image-data-obtaining means for obtaining second image data from the imaging means by so setting the emission period or the emission-start timing and the exposure period or the exposure-start timing in order to receive a part of the light reflected or scattered from the object over the whole exposure period, the part corresponding to the flat period of the pulsed light; the image-data-obtaining means further including a third image-data-obtaining means for obtaining third image data from the imaging means by so setting the emission period or the emission-start timing and the exposure period or the exposure-start timing in order to receive the part of the reflected or scattered light for a time according to the round-trip time for the distance to the object; the range-image-data-generating means including a first arithmetic means for finding reference image data by subtracting the first image data from the second image data; the range-image-data-generating means further including a second arithmetic means for finding intensity image data by subtracting the first image data from the third image data; the range-image-data-generating means further including a third arithmetic means for finding the range-image-data by calculating the ratio between the reference and intensity image data.