| 摘要 |
PURPOSE:To make it possible to detect the presence or absence of the powder in a container by certainly receiving emitted light, by simple constituion such that a light pervious spacer is provided to the head surface of a reflective sensor having a light emitting part and a light receiving part mounted to the head surface thereof. CONSTITUTION:A transparent spacer 5 is embedded in a reflective sensor 1 and closely contacted with terminal surfaces of optical fibers 2, 3. A head 6 is attached to the side wall of a container and, when the powder in the container is contacted with or slightly separated from a detection surface, light L emitted from the optical fiber 2 transmits the transparent spacer 5 and reflected by the surface of the powder to be received by the light receiving fiber 3. As mentioned above, because the spacer 5 is provided to the head surface of the sensor 1, emitted light is certainly received even if the head surface is covered with the powder and it is unnecessary to coincide the center line of a light emitting and receiving head and the presence or absence of the powder can be certainly detected by simple constitution. |
