Patent ID: 6950249

Claim:
A Z-axis assembly for an optical inspection apparatus comprising: a base; first and second rails secured to said base, said first and second rails being parallel to each other; a plurality of carriages supported by ball bearings for translatory movement parallel to the Z-axis on each of said first and second rails, said ball bearings having contact points with respective of the first and second rails, the contact points lying on at least a first line of travel for carriages on one of the first and second rails and at least a second line of travel for carriages on the other of the first and second rails; a support structure secured to said carriages; a lens assembly secured to said support structure so as to be movable parallel to the Z-axis and said lines of travel, said lens assembly including an optical axis parallel to the Z-axis and said lines of travel, but spaced apart from the lines of travel so that said optical axis and all lines of travel lie on a common plane.