| 摘要 |
PURPOSE:To simply and accurately detect a surface flaw at a high speed, by receiving a reflected optical image obtained by irradiating the surface of an object to be inspected with parallel light at an irradiation angle of 20-30 deg. from a direction different from the direction of the pattern on the surface of the object to be inspected while treating the obtained image signal. CONSTITUTION:When a flaw is present, because irradiation performed at an angle of 45 deg. with respect to a pattern, only scattered light due to the flaw is received by an ITV camera 7 and, at this time, said scattered light is brought to high intensity because illumination is simultaneously performed from the four quarters. In addition, because a semiconductive pellet 4 is irradiated at an irradiation angle of 20-30 deg.C with respect to the surface thereof, reflected light due to the slight uneveness of the surface 4a thereof becomes remarkably small and incovenience, such that only the edge part of a deep flaw is bright and scattered light is not detected, is not generated. The photographed image signal obtained by the ITV camera 7 is applied to a signal treating circuit 9 through a binary circuit 8 to be subjected to signal treatment therein and the presence of a flaw is detected while informations such as the position, the size and the shape thereof are discriminated to be displayed by a display apparatus. |
