| 摘要 |
<p>The detector comprises a photo cell (4) and two spaced reflective surfaces (5, 6) facing the photo cell (4), located one on either side of the conveyor belt (1). The top edge of the surface (6) nearest the photo cell (4) is aligned with the top surface of the conveyor belt (1). The other surface (5) is approx. spherical and curves upwards from the level of the conveyor belt (1). The surface (6) nearest to the photocell (4) may be less reflective than that on the opposite side of the conveyor belt (1) and it may be divided into two, to provide a scanning aperture. The detector is used to distinguish between parcels and letters passing along a conveyor belt, for automatic sorting.</p> |
