PURPOSE: To simplify the setting of part frames and to inspect parts at a high speed by setting part images surrounding one or a plurality of changed parts when the changed parts are detected in the images of slit light and then the images of the light without the changed parts are detected.
CONSTITUTION: A part detecting circuit (CPU) 13 detects changed parts X in the images of slit light which is sequentially inputted by the relative movement with a part to be inspected and then detects the images of the slit light without the changed parts X. At this time, part frames F1 and F2 surrounding one or a plurality of the detected changed part X are set, and the data of the part frames are sent out. Namely, in the part detecting circuit 13, the images of a master substrate 1 and a sample substrate 2 are picked up with a visual sensor for the master substrate 11 and a visual sensor for the sample 12 at the same time. The images located on the corresponding positions on the substrates are compared in a comparing circuit 17. At this time, only the images in the regions specified by the part frames F1 and F2 are compared. Thus, the required amount of the comparison data can be made less, and the processing time becomes short by that amount.
SUGIOKA SEIJI
BABA SHINICHI
