| 摘要 |
PURPOSE:To make it possible to correct the positional deviation of an objective figure, by a method wherein the direction and the degree of the positional deviation of a specific pattern are detected by a position detecting signal and a delay circuit is selected to sent a control signal value corresponding to the amount of the positional deviation. CONSTITUTION:After objects 1, 2 to be photographed such as print boards are photographed by photography apparatuses 3, 4 to be converted to electric signals, said signals are compared with definite voltages outputted from reference voltage generators 7, 8 and the obtained binary signal is delayed to be outputted. A pattern position difference calculating circuit 12 receives the signals from delay circuits 10, 11 to detect the respective specific positions in the objects 1, 2 to be photographed and the difference thereof is calculated to select one circuit among the delay circuits 10, 11 corresponding to the calculated result while an output control signal value corresponding to the position difference is outputted to the selected delay circuit 10 or 11. As the result, even when the two-dimensional figures of two objects to be photographed generate mutual positional deviation, an faulty part can be detected by simple comparing inspection method. |
