| 摘要 |
<p>PROBLEM TO BE SOLVED: To accurately detect the presence/absence of a transparent object by providing a light emitting section, a light receiving section, and a light converging means, with the light emitting and receiving sections being arranged so that the light emitted from the former can be made incident on the latter, and detecting the intensity distribution of the light based on the extent of the light converged by the converging means. SOLUTION: The light emitting section 1 and light receiving section 2 are arranged in a mutually facing state so that the light V1 emitted from the section 1 can be made incident on the section 2 and a lens 6 is positioned as a converging means near the section 2 within the irradiating extent of the light V1. A transparent object P is passed through the irradiating area with the light V1 between the section 1 and lends 6 in the crossing direction. The lens 6 is slightly inclined in the y-axis direction. When the object P does not exist in the area, a circular converged light spot is formed, but, when the object P exists in the area, an elliptic converged light sop is formed in the section 2. Therefore, the presence/absence of the object P can be detected from the shape of the light spot.</p> |
