Patent ID: 6100986
Filing Date: 2000-08-08
Classification: G01B

Abstract:
A device for measuring the width dimension of an object which moves relative to the device along a transport direction, the width dimension of the object lying parallel to the transport direction, said device comprising:a light source generating elongated beam of light parallel to the transport direction, which beam of light is intercepted by the object to be measured during the relative movement of the device and object;a video camera having a viewing field containing a plurality of scanning lines searchable in a direction parallel to the transport direction;mirror means for applying the beam of light to the visual field of the camera, said mirror means comprising first and second concave, parabolic mirrors, the parabolic shape of the mirrors having a focal axis, the focal axes of the first and second parabolic mirrors lying normal to the transport direction and in a common plane, said first parabolic mirror being spaced from said light generating source so that the object to be measured intercepts the beam of light between the light generating source and the first parabolic mirror, said first and second parabolic mirrors being arranged such that the concavities of said mirrors are facing each other and so that the focal axes of the mirrors are lying at an angle of 90.degree. to each other, said second parabolic mirror receiving light beam reflected from said first parabolic mirror and applying it to the viewing field of said video camera so that the amount of blocking of the beam of light by the object to be measured may be sensed by searching a scanning line of the viewing field; andmeans coupled to said video camera for determining the width of the object to be measured from the amount of blocking of the beam of light by the object.