Patent ID: 6943874

Claim:
An apparatus for inspecting a surface, said apparatus comprising a housing, in which means for emitting and receiving a light beam are arranged, having a front wall turned towards the surface with a transparent window on the front wall to allow said light beam to pass between said emitting and receiving means and the surface, and having an optical coupling device arranged on the outer surface of said wall so that its optical axis is essentially parallel to the axis of said light beam, wherein said optical coupling device comprises: a fluid dispenser component fixed to said wall and pierced with an opening to allow said light beam to pass through; a hollow cylindrical nozzle leaktightly assembled with said fluid dispenser component and arranged as an extension of said opening, said fluid dispenser component being provided with an inlet orifice for a coupling fluid and with passages connecting said inlet orifice to said opening; a mobile tubular component, arranged partially within said cylindrical nozzle, as an extension of the latter, and capable of sliding within said hollow cylindrical nozzle; the hollow cylindrical nozzle having a uniform first inner diameter over most of its length and a second inner diameter over an outlet portion, said second inner diameter being smaller than said first inner diameter to form an internal shoulder near the outlet of said hollow cylindrical nozzle; said mobile tubular component having a head with a first external diameter slightly smaller than said first inner diameter of said cylindrical nozzle, and an elongated portion with a second external diameter slightly smaller than the second inner diameter of said outlet portion of the cylindrical nozzle to form an external shoulder of said tubular component; said elongated portion of the mobile tubular component being inserted into and projecting out of said outlet portion of the cylindrical nozzle and the external shoulder cooperating with said internal shoulder to stop the movement of said mobile tubular component in said hollow cylindrical nozzle.