Station and method for checking tyres

A station for checking tyres in a tyre production line, comprising:

• a) a support adapted to support a tyre set on a sidewall thereof and to rotate the tyre around a rotation axis thereof;
• b) an apparatus;
• and
• c) a movement member,
• wherein the apparatus comprises:
• b1) a support frame;
• b2) a flange for attaching said support frame to the movement member;
• and
• b3) an acquisition system for acquiring digital images of a surface of the tyre mounted on the support frame, the acquisition system comprising:
• b3i) a linear camera having a first optical axis, an optical plane, a focal plane and an objective line belonging to the focal plane and to the optical plane, and
• b3ii) an illumination system adapted to illuminate the objective line, the illumination system comprising a light source and an optical lens system having a second optical axis,
• wherein the optical lens system comprises a first converging lens, proximal to the light source, and a second converging lens arranged on the side opposite the light source with respect to the first lens,
• wherein the light source, the first lens and the second lens are coaxial with the second optical axis,
• wherein the first lens has a numerical aperture greater than or equal to 0.5, and
• wherein an aperture of the second lens is greater than the numerical aperture of the first lens.

A method for checking tyres, the method comprising:

• a) arranging an acquisition system comprising:
• a linear camera having a first optical axis, an optical plane, a focal plane, and an objective line belonging to the focal plane and to the optical plane;
• and
• an illumination system adapted to illuminate the objective line, the illumination system comprising a light source and an optical lens system having a second optical axis,
• wherein the optical lens system comprises a first converging lens proximal to the light source, and a second converging lens arranged on a side opposite the light source with respect to the first converging lens,
• wherein the light source, the first converging lens and the second converging lens are coaxial with said second optical axis,
• wherein the first converging lens has a numerical aperture greater than or equal to 0.5;
• and
• wherein an aperture of the second converging lens is greater than an aperture of the first converging lens;
• b) arranging a tyre to be checked having a surface and moving the acquisition system close to the tyre;
• c) rotating the tyre with respect to the acquisition system in a manner that distinct linear surface portions of the tyre are successively situated in proximity to the objective line;
• and
• d) successively acquiring, by means of the acquisition system, a series of respective linear images of the distinct linear surface portions to obtain an image of a circumferential surface region via combining of the series of respective linear images.