| 摘要 |
PURPOSE:To enables a highly accurate and quick width measurement in the boundary of the end rim of a spinning hole in a cap plate by computing the deformation of the boundary based on the positional relationship between two kinds of end rim images obtained at the first and second steps. CONSTITUTION:When a second projector 12 projects light, an image pertaining to the end rim 7 of the side 6 of a spinning hole 2 is received and taken with a light receiver 10 comprising a TV camera and stored into a memory 14 via an A/D converter 13. The stored data is converted into an area value SI with a first area computing element 16 and the inner circle R1=(SI/pi)<1/2> is calculated with a first radius calculation circuit 17. Then, on the part of the reflected light from the first projector 11, an image of the end rim 5 is received and taken with the light receiver 10 and stored into the memory 14. The data is converted into an area value S2 with the second area computing element 18 and the outer circle R2=(S2/pi)1/2 is calculated with the second radius calculation circuit 19. A subtractor 20 calculates the average width W corresponding to the width of the boundary 8 based on W=R2-R1. |
