Patent ID: 8254022

Claim:
A sample positioning stage for positioning a sample to be inspected relative to an optical inspection device, the stage comprising: a first generally planar body on which a sample to be inspected can be carried; a second body directly coupled to the first body via bearings extending between them which constrain movement of the first body relative to the second body to a first plane that is substantially parallel to the plane of the first body; a drive system being selectively operable in a first mode to drive the first and second bodies in the first plane relative to each other toward a demanded relative position received from an electronic position input device, and a second mode in which the drive system provides less resistance to the relative movement of the first and second bodies in the first plane by an external force exerted on at least one of the first and second bodies than in the first mode, the drive system being engaged in both the first and second modes; and a selector operable to change the mode of operation from the first mode to the second mode in response to an input received at the stage.