| 摘要 |
PURPOSE:To streamline a test by placing printed boards having the same pattern on two sub-tables installed on X and Y tables so as to pick up an image and returning again the table to a dissident point so as to check it again when dissidence is found. CONSTITUTION:The printed boards 11 and 12 having the same pattern are placed on fine adjusting DELTAX, DELTAY tables 31 and 32 installed on a table 21 mov able in X and Y directions. Image pick up devices 41 and 42 are fixed so as to pick up the images at the same position on the printed boards. The outputs of the image pickup devices 41 and 42 are stored as a binary-coded video signals in memory devices 61 and 62 disposed in a matrix through binary-coding circuits 51 and 52, and a defect deciding circuit 7 detects a defect with the aid of the dissidence of signals of both systems. Prior to the test, the outputs of the binary- coding circuits 51 and 52 detect 8 dislocation, and a control circuit 9 corrects the dislocation by the fine adjusting motors 33 and 34. If a defect is detected, the table 21 is returned in directions X and Y to check it again. Thus faulty information due to dust can be prevented. |
