Patent ID: 11971362
Assignee: NUOVA OMPI S.R.L.
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G  H

Claim 8:
9. A method for inspecting transparent, cylindrical containers containing transparent or semi-transparent viscous or gel products, in particular for medical applications, comprising the steps of:
providing a transparent cylindrical container containing a transparent or semi-transparent viscous or gel product, supported so as to rotate around a vertical axis of rotation, coinciding with an axisymmetry axis of said container,
providing a support and/or gripping device for said cylindrical container, suitable for supporting it and provided with means for making it rotate about a vertical rotation axis, coinciding with a cylindrical axisymmetry axis of said cylindrical container,
providing a video camera directed so as to frame and capture images, in a form of pixels, of a window, the window being on a side wall of the cylindrical container, said side wall having a thickness equal to the difference between an outer radius, i.e. a radius of an outer surface of the side wall, with respect to the cylindrical axisymmetry axis, and an inner radius, i.e. a radius of an inner surface of the side wall,
providing a lighting device, placed opposite the video camera with respect to the cylindrical container, so as to back-light said cylindrical container, opposite the video camera,
controlling a rotation of the cylindrical container by means of the support and/or gripping device at constant angular speed around the vertical rotation axis,
controlling the activation of the video camera so as to acquire ‘n’ images of said window, for a predetermined number ‘n’ of regular angular intervals Δθ, during the rotation of the cylindrical container,
identifying points of said images which can be detected as impurities,
measuring a median displacement, ΔSmed, of each of said points during said regular angular intervals and comparing the median displacement to a discriminating value equal to a product of an internal radius of the cylindrical container and said regular angular intervals,
for each point of the identified points, classifying the respective impurity identified by the point as external to the container if said median displacement of the point is greater than said discriminating value, and classify the respective impurity identified by the point as internal to the container if said median displacement of the point is less than said discriminating value.