| 摘要 |
PURPOSE:To detect a beveling welding line highly accurately with a simple constitution, by employing such constitution that a beam of light is projected on a beveling welding line from a light-projecting means placed along a sensing axis through a microlens, and the reflected light received through microlenses being arranged symmetrically. CONSTITUTION:The light from an He-Ne laser 11 is applied onto a work WA through a condenser lens 112, an optical fiber 10 and a microlens 13, to form a bright portion S1a. Microlenses 23 and 33 arranged at the positions symmetrical with respect to the microlens 13 receive the rays reflected from visual fields S2a and S3a respectively. Said rays are inputted to phototransistors 21 and 31 through optical fibers 22 and 32 respectively. The outputs thereof are inputted to a subtractor 40 through amplifiers 61 and 62, filter circuits 81 and 82 and detectors 91 and 92. Then, regulation is effected so that said differential output, that is, the distance (d) between the symmetrical axis H of the visual fields S2a and S3a and a welding line WL becomes zero. Thereby, the welding line WL can be detected highly accurately with a simple constitution. |
