Double group reading matrix type photoelectric coded circle

A matrix photoelectric coded disk with double-group reading belongs to a photoelectric coded disk in the technical field of photoelectric measurement. The technical problem to be solved is to provide a matrix photoelectric coded disk with double-group reading. The technical proposal of the solution comprises a coded disk and a slit disk; wherein, the coded disk is provided with N plus 2 circles of coded tracks, N is a natural number larger than or equal to 3; the slit disk is a disk with double-group reading and has N plus 2 circles to be matched with the coded disk; moreover, the diameter of each circle of the slit disk is equal to that of the corresponding circle of the coded disk from the smallest inner circle to the largest outer circle. The matrix photoelectric coded disk with double-group reading is formed after arranging the coded disk and the slit disk with double-group reading on the main shaft of an encoder.