摘要 |
Two stereoscopic images of the surface of an inspected object are projected by two different lens systems to two separate video cameras for recording thereby and for display via a CPU on a 3D monitor. The optical axes of the two lens systems are equiangularly spaced from a central Z axis extending normal to the object plane, so that the height of a feature on the surface of the workpice may be calculated by determining the difference in the amount of lateral offset in the X direction from the center of a displayed image of a given feature as shown in one of the displayed images from the amount of its corresponding lateral offset in the other image, and then calculating Z in accordance with the formula Z=the difference in the offset in the X direction divided by twice the tangent of the angle of inclination of a respective viewing axis relative to the Z axis. Alternatively, the two images may be superimposed to form a stereoscopic image, and the two lens systems are shifted on the Z axis until the slight offset images of the feature coincide.
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