| 摘要 |
PURPOSE:To improve working line profiling accuracy as compared with the conventional one by constituting a pattern extraction circuit provided to the preceding stage of a pitch processor from a band-pass filter to extract a signal component of an interference pattern which is formed by projected laser light from a picture signal. CONSTITUTION:A laser projector 4 projects slit light 8 in a direction to cross a weld line of an object to be welded. An image pickup device 2 receives a reflected image 8A of said slit light 8 through an optical filter 3 and scans and picks up the image 8A on image like figure (a) and sends out its picture signal to a signal separation circuit 5. Then, the circuit 5 separates a periodic signal from the picture signal and inputs the separated picture signal to the speckle pattern extraction circuit 6. The signal component of spatter light is completely eliminated from the picture signal passing through the circuit 6 like figure (c) and only the picture signal of the image 8A by the slit light 8 is supplied to the picture processor 7. Then, the processor 7 detects a feature point (namely, point on weld line) 8B shown in figure (a) from the above- mentioned picture signal inputted. |
