US Patent 7848634 Method and apparatus for identifying interchangeable lenses

An interchangeable lens connects in a prescribed position to a support surface on a camera of a camera system using a locking apparatus. A method and apparatus for identifying interchangeable lenses uses optical radiation. After the locking operation is performed, a defined optical radiation is directed from two or more, preferably six, light transmitters arranged in the support surface to reflecting or absorbing surfaces on the locking apparatus which are assigned to said light transmitters. The radiation returning from the respective reflecting/absorbing surfaces is picked up by light receivers arranged next to the light transmitters in the support surface. A binary coded signal for identifying the interchangeable lens is formed from the output signals of the light receivers.