Optical method of reading the shape of a profile and application thereof to reading the inside edge of a spectacle frame rim

摘要

An optical non-contact method of reading the three-dimensional shape of a profile in accordance with the luminous section principle consists of scanning the profile with a plane light beam intersecting the profile transversely, simultaneously reading the trace of the plane light beam on the profile by means of an optical receiver having an optical pointing axis at a constant non-zero pointing angle to the light beam at a series of positions along the profile, and deducing the three-dimensional shape of the profile from the readings effected at these various positions. On each reading, the light beam whose trace on the profile is read by the optical receiver is chosen from a plurality of predefined light beams which can be activated alternately. The non-contact optical reading method is particularly suitable for reading the three-dimensional shape of the inside edge of a spectacle frame rim, known as the bezel. A specific device is used to implement the method in this particular application.