Abstract
The 3-D vision system we developed uses laser scanning, and simultaneously produces range and intensity images covering a wide area. 3-D vision is indispensable in image processing for factory automation. Conventional, practical slit-light techniques using a TV camera have a limited narrow measurement area, take too long to accept input images, and cannot produce range and intensity images simultaneously. We developed a camera we call the 3-D imager and a vision system based on it. The 3-D imager uses a laser diode beam to scan the measured area and obtains range and intensity data at all points on the scan line. Range measurement is based on triangulation. The vision system, which consists of a 32-bit CPU (68020) and 12M-byte image memory, has three main features: (1) 3-D measurement covers 2048-by-3076-pixel image formed in one image input sequence. (2) Measurement is fast: The system takes 12 seconds to produce data for an entire 6-million-pixel area. (3) The system processes range and intensity data simultaneously. The 256-height-level range image is used to determine an object's shape, and the 256-gray-level intensity image to determine the surface texture, markings, and other features. When used to inspect PC boards, the system detected missing, shifted, and floating components. The inspection resolution is 125 pm in along the X and Y axes and 30 lam along the Z axis.
