Patent ID: 7485842

Claim:
An optical proximity sensor adapted to be mounted in a liquid-jet instrument having a spray head for spraying a jet of liquid, the optical sensor serving to evaluate a distance between the optical sensor and a given surface onto which the liquid is to be sprayed, the optical proximity sensor comprising: a printed circuit having a first face and a second face on which at least one light-emitting element and at least one light-receiving element are positioned, the light-emitting and the light-receiving elements being adapted to evaluate the distance between the light-emitting and the light-receiving elements, and the given surface; an intermediate part mounted on the second face of the printed circuit, and includes at least two through recesses in which the light-emitting and the light-receiving elements of the printed circuit are received; and protective means that cover at least one of the two through recesses, the protective means presenting optical properties adapted to the wavelength of the light used by the light-emitting and the light-receiving elements so as to enable the light to be focused, wherein the printed circuit and the intermediate part are provided with through holes which are mutually superposed to form a passageway serving to enable the liquid to be sprayed from the liquid spray head.