| 摘要 |
<p>PURPOSE:To make it possible to inspect efficiently a three-dimensional shape of a pattern of a wiring board as well as a plane shape thereof by applying lights of the three primary colors to the wiring board and by converting an optical image thereof into video signals by a color television camera. CONSTITUTION:Lights of the three primary colors, blue, green and red, are applied one the surface and the rear of a wiring board 10 by three irradiation lamps 31, 32 and 33 emitting the lights of the discrete colors respectively. A color television camera 34 picks up an image of the board 10 and converts the optical image of the surface thereof into video signals of the three primary colors of the lights, inputting the red video signal to a two-dimensional logic circuit 35 and the blue and green video signals to first and second three-dimensional logic circuits 36 and 37 respectively. The circuit 35 calculates the width of a pattern 12 from the red video signal and determines the quality of the pattern, i.e., whether a short-circuit fault 13, a disconnection fault 14 or the like exists or not, on the basis of the calculated width of the pattern. Based on shadow patterns formed by the lamps 31 and 32, the circuits 36 and 37 determine likewise the quality of the three-dimensional shape of the pattern 12, i.e., whether a projection fault 16 or the like exists or not, from the blue or green video signal.</p> |
