| 摘要 |
PURPOSE:To allow the quantity of light of a light source to arrive at a photodetector with virtually no reduction thereof by passing the light emitted from the light source through the notched part of a light shielding film to form a light signal and concentrating this light signal at the photodetector. CONSTITUTION:Light from a lamp 23 enters a photoconductor 21 from an incident surface 21a. The light advancing in the arced surface direction is reflected from a reflecting film and most of the light of the lamp 23 advances toward a reflecting surface 21c. Since this surface 21c is formed along the parabolas centering at a through-hole 22, the light reflected by the surface 2c is the parallel light toward an exit surface 21b. This parallel light is also parallel in the crossing direction of the photoconductor 21 because the surface 21b is a convex lens shape. The parallel light out from the exit surface 21b passes through the torus lens part 6a of a disc 6 via the notched part 7a of the light shielding film 7 of the rotary disc 6 and arrives at photoconducting wires 14a-14f, 15a-15f, 16a-16f, thereby digitally displaying the weight of a person riding on a weighing cradle. |
