Patent ID: 7466430

Claim:
A method of optically scanning a pneumatic tire of a vehicle wheel the method comprising the steps of: rotating the vehicle wheel about a stationary axis; scanning the surface of the pneumatic tire while the wheel is rotating by emitting three light beams from three given positions onto the surface of the pneumatic tire forming a light spot in each given position; receiving three beams reflected by the surface of the pneumatic tire corresponding to each of the three light beams for measuring the distance of each of the light spots relative to a reference position; measuring a rotary angle position of the vehicle wheel associating with the measured distances; and determining dimensions and positions of the pneumatic tire or constituent parts of the pneumatic tire based on the measured distances of the three light spots and the associated rotary angle position of the vehicle; wherein one of the light beams scans the tire tread surface, and the other two of the light beams scans the tire side walls at the inside and the outside of the wheel such that all external surface spots of the tire are scanned.