| 摘要 |
PURPOSE:To enable recognition of welding spot and the state of welding without influenced by condition of external light by incorporating solid state image pickup element having a light checker in front and a solid state light emission element having linear polarization characteristics. CONSTITUTION:A solid state image pickup element 11 for recognizing welding spot A and a solid state light emission element 12 having linear polarization characteristics are incorporated in a visual sensor 10. Linearly polarized light E emitted from the element 12 passes through a condensing optical system 15 and reflected by a polarized light beam splitter 14 and led to the optic axis of an incident optical system 13. The light E is converted from linearly polarized light to circular polarized light by a quarter wavelength plate 24 and projected onto a spot A. In this case, when the light E enters the optical sytem 13, reflected light R in the direction of the element 11 is generated, but arrested by the splitter 14. The reflected light R, even a few, reaches the element 11, but arrested by placing a light checker 16 in front of the element 11. On the other hand, reflected light C at the spot A arrives at the element 11, and forms an image on the element 11. |
