| 摘要 |
PURPOSE:To execute a precise test without a useless time by testing a unit pattern simultaneously with the extraction of a macro-characteristic variable and determining a threshold to be used for the test of the succeeding unit pattern on the basis of the extracted characteristic variable. CONSTITUTION:The output of a video input device 4 is digitized by an A/D converter 9 and inputted to a density frequency detecting circuit (macro-characteristic extracting circuit) 21 and a defective area extracting circuit 16. A computer 1 sends threshold information to a line 17 on the basis of an output for the preceding unit pattern of the density frequency detecting circuit 21 and the defective area extracting circuit 16 extracts a defective area on the basis of threshold information and ideal pattern data sent from a storage circuit 12 and a read control circuit 13 and sends the extracted area to a fatal property discriminating circuit 19. The circuit 19 matches the sent data with the ideal pattern data, and when the fatal property is discriminated, the X, Y coordinates are stored in a built-in storage circuit, and after completing the test, sent to the computer 1.
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