Patent ID: 7714302

Claim:
An apparatus for inspecting a surface containing a material that emits luminescent radiation in response to absorbing excitation radiation, comprising: a housing, a laser disposed in or adjacent the housing, a sensor opening defined in the housing and being arranged and constructed to permit emission of excitation radiation generated by the laser and to permit admission of the luminescent radiation emanating from the surface in response to the excitation radiation, a sensor arranged and constructed to monitor whether ambient light is being admitted between an edge of the sensor opening and the to-be-inspected surface when the surface is in contact with the sensor opening, a safety circuit arranged and constructed to permit the laser to be actuated only when the sensor detects an at least substantially completely light-impermeable contact between the edge of the sensor opening and the surface; and at least one ambient light sensor disposed on or in the housing, wherein the safety circuit is further arranged and constructed to permit the laser to be actuated only when the ambient light sensor detects ambient light around the housing.