| 摘要 |
PURPOSE:To inspect a pattern at a high speed without being affected by the up-and-down movement of an object to be inspected, by dividing a light cut image obtained by a light cutting method into upper and lower images to compress two images in a height direction and respectively detecting the compressed images by two CCD line sensors. CONSTITUTION:A light cut image M is divided into an upper part M1 and a lower part M2 by a splitting prism 15 to obtain two images each having a height half that of the original light cut image M. Next, these images are compressed only in a height direction by cylindrical lenses 16-19 to obtain linear images short in the height direction with respect to the lateral direction. These linear images are formed on CCD line sensors 20, 21 leaving surplus. Therefore, the linear images can be detected without being shifted from sensors 20, 21 in spite of the variation of the light cut image M in the height direction with the up-and-down movement of the wiring pattern on a printed circuit board to be inspected. Since the image formed on the sensors 20, 21 have the light intensity distribution corresponding to the high and low parts of the object to be inspected, the output difference between the sensors is judged by a judging means to make it possible to detect the width and height of the pattern.
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