| 摘要 |
<p>PURPOSE:To secure large S/N ratio between regular reflected light from a body to be detected and the reflected light inside the detecting body itself, such as the reflected light from a holder inner wall, the reflected light from an optical lens portion, the reflected light from a optical filter, or the like (remaining light), to increase amplification sensitivity so as to set a sufficiently long detecting distance and secure large noise resistance against disturbance by reducing the remaining light. CONSTITUTION:A photoelectric switch is composed of a light projecting element 6, a light receiving element 7, a holder 8 positioning these elements and fitting inside, an optical lens portion 9, and an optical filter 10. A light scattering work face is formed on the inner wall face S of the holder 8. An approximately V-shaped groove 17 is formed in the optical filter 10 so as to position on a equidistance line between the light projecting element 6 and the light receiving element 7, while a slit 18 is formed in the middle of a light projecting lens 9a and a light receiving lens 9b formed in the optical lens portion 9. The extended portion of a shielding barrier plate 8b formed connecting to the holder 8 is inserted into the slit 18.</p> |
