LASER PROFILE METRE Russian patent published in 2009 - IPC G01B11/24 

FIELD: instrument making.

SUBSTANCE: proposed laser profile metre serves to check up sophisticated-shape products, e.g. turbine blade, by light section method. The proposed instrument incorporate the blade lengthwise travel and fastening mechanism, two lasers with cylindrical lenses, for blade slot illumination, arranged in symmetry with the blade and on its both sides. The said lenses form flat light beams in the plane perpendicular to the blade lengthwise axis. It comprises TV camera and computer to process parametres of cross section under control. Additionally, the proposed metre comprises two lenses with their optical axes lying in the plane formed by the lasers axes and blade lengthwise axis. The said lenses are arranged in symmetry at angles α of the blade lengthwise axis. The metre includes also a beam splitter arranged between the first additional lens and TV camera lens, on its optical axis aligned with that of the first additional lens. It, further on, comprises the reflector, arranged in the plane perpendicular to that formed by lens axes at the point of intersection of the second additional lens optical axis, with perpendicular to TV camera lens axis, run through the point of its intersection with the splitter reflecting face in the plane, formed by the additional lens axes at the angle 2γ=(90°-2α)/2 to the second additional lens axis. Additionally introduced are two optical transparent plane-parallel plates made in material with its transmission spectrum maximum complying with the laser radiation wavelength, while its spectral transparency, outside the wavelength range, is minimum for the TV camera spectral sensitivity range. Aforesaid plates are fitted ahead of entrance pupils of additional lenses to revolve relative to mutually perpendicular axes crossing the additional lens optical axes. Thickness of the said plates B(mm) and refractivity are selected from the expression . The plate material, constant and plate diametres D_n satisfy the requirement D_n≥D_K, where D_K is the diametres of additional lens entrance pupils.

EFFECT: higher accuracy of inspection.

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