Abstract: A closed circuit TV camera with a fixed focus lens, is used to measure the vertical displacement from and longitudinal distance from an industrial robot arm to checkered-row target pattern, i.e., a row of alternate black and white squares. The pattern is located in a fixed spatial relationship with a targeted object and is identified by the appearance of a burst of pulses in the video output during the horizontal scan. The vertical displacement of the target pattern from the optical axis of the camera is obtained by averaging the vertical deflection voltages, when the pattern is first acquired and when the pattern is just lost. The longitudinal distance to the target plane is obtained from the pulse repetition frequency within the burst, which increases linearly with distance.