| 摘要 |
PURPOSE:To automatically and correctly inspect height of an IC wire irrespective of background conditions by a method wherein depth of field of a camera is made coincide with an allowable height range of a linear object, and whether or not a recorded image is focused is detected. CONSTITUTION:When depth of field of a camera is aligned with allowable height ranges ha, hb, hc of an IC wire, a wire having normal height is recorded in focus and a defective wire is recorded out of focus. With height data stored in a controller 19, a camera 14 is sequentially moved in a range of ha to hc while an aperture 13 is driven by a driver 17 to control a lens diameter so that depth of field is a specified value. By recording images sequentially in this state, video signals are AD-converted 20 and stored in an image memory 21, and an inspection circuit 22 is used to inspect whether or not the image is in focus according to gradient profile to judge whether an object is good or defective. |
