Abstract: A three-dimensional image capturing device comprises a light source and an imaging device, such as a CCD, having a plurality of photo-diodes. The light source outputs a pulsed distance measuring light beam simultaneously with a discharge of unwanted charges from the photo-diodes due to an electric charge discharging signal. A reflected light beam, generated by a measurement subject due to the distance measuring light beam, is received by the photo-diodes. When a predetermined time has elapsed since the output of the distance measuring light beam, an electric charge transfer signal is output so that electric charge, i.e. signal charge accumulated in each of the photo-diodes, is transferred to the vertical transfer unit. The electric charge and the electric charge discharging signal are repeatedly output, so that the signal charge is integrated in the vertical transfer unit.