Abstract: The sensor comprises a structured light source (5, 6, 7) which is adjustable so as to interchange the positions of contrasting areas of the pattern it provides, a detector (1) which comprises an array of detector elements having dimensions matched to the pattern produced by the light source, an optical system (2, 8) for projecting a primary image of the light source pattern onto an object (3) that is to be sensed and for forming a secondary image on the detector (1) of the primary image thus formed on the object (3), positioning means (4) for moving at least part (2) of the optical system so as to vary the focussing of the primary image on the object (3) and processing means (12) for analyzing signals produced by the detector (1) in conjunction with information on the adjustment of the optical system (2, 8). The optical arrangement is `confocal` so that, when the primary image is in focus on the object (3), the secondary image on the detector (1) is also in focus.

Abstract: The device comprises a structure (1) supporting a light beam source (2), a beam guide and a camera assembly (3), the light beam source (2) being arranged to direct an outgoing beam of light (I) into the beam guide which projects the outgoing beam (P) onto a target surface to sweep the beam around an endless path (E) on the target surface, scans synchronously around the endless path (E) to receive light returning from the portion of the path (E) illuminated by the outgoing beam (P), and directs the returning light (P) onto a light sensor (12) provided in the camera assembly (3); the beam guide comprising a rotatable wedge prism (5) arranged such that the outgoing beam (2) is transmitted through relatively inclined surfaces (9, 10) of a projecting element of the prism (5) as it is rotated to direct the beam (P) to sweep around the endless path (E) and the light returning from the portion of the path illuminated by the beam (P) is received through relatively inclined surfaces (9, 10) of a receiving element of th