Abstract A small cross-sectional beam of radiant energy from a source such as a laser is directed by way of an optical scanning device onto a surface to be inspected. The intensity of the radiant energy reflected from the surface of the object is measured to determine the quality of the surface. The intensity may be equalized by focusing the reflected energy and providing aperture means so located that energy from mid-scan areas passes through the equalizing means relatively unimpeded to be measured while energy from points closer to the mid-scan point is intercepted to a greater degree. If the surface to be inspected is moving in a direction having a component perpendicular to the direction in which the beam is deflected by the scanning device, the scanning device need only deflect the beam in one plane. If the object is stationary, the scanning device may include two deflecting means in tandem, one deflecting the radiant energy beam in one direction and the other deflecting it in a perpendicular direction.
Apparatus for inspecting the surface of an object located generally at an inspection position, the exact dimensions and location of the object being undetermined, said apparatus comprising: a. means for generating a collimated beam of radiant energy; b. a scanner for scanning said beam across the inspection position; c. a first photodetector positioned to receive radiant energy reflected from the inspection position; d. second and third photodetectors located at the inspection position and positioned to receive the beam at its opposite scanning extremes, said second and third photodetectors being spaced sufficiently close together such that an object at the scanning position partially overlaps both of said second and third photodetectors; e. means responsive to the outputs of said second and third photodetectors for generating an edge contRol signal; and f. inspection signal generating means, gated by said edge control signal, for generating an inspection signal in response to the output of said first photodetector.
Claim 2
Dependent Claim
154 words
Apparatus for inspecting the surface of an object located generally at an inspection position, the exact dimensions and location of the object being undetermined, said apparatus comprising: a. means for generating a collimated beam of radiant energy; b. a scanner for scanning said beam across the inspection position; c. a first photodetector positioned to receive radiant energy reflected from the inspection position; d. second and third photodetectors located at the inspection position and positioned to receive the beam at its opposite scanning extremes, said second and third photodetectors being spaced sufficiently close together such that an object at the scanning position partially overlaps both of said second and third photodetectors; e. means responsive to the outputs of said second and third photodetectors for generating an edge contRol signal; and f. inspection signal generating means, gated by said edge control signal, for generating an inspection signal in response to the output of said first photodetector.
Claim 3
Dependent Claim
16 words
Apparatus as defined by claim 1 wherein said beam of radiant energy is a laser beam.
Claim 4
Dependent Claim
14 words
Apparatus as defined by claim 2 wherein said scanning means is an optical spinner.
Claim 5
Dependent Claim
45 words
Apparatus as defined by claim 3 further comprising a lens positioned to collect laser light energy reflected from said inspection position off said spinner as a solid angle of light surrounding the impinging laser beam, said first photodetector receiving the light collected by said lens.