PURPOSE: To enable the transmission of optical fiber to be carried out with high accuracy, by a method wherein the displacement of axis is converted to the movement of position, the distance between the reflected plate appended with a position and the end surface of input light of optical fiber fixed to a cylinder being changed, and the displacement amount of axis is detected with the change of input light amount to the end surface.
CONSTITUTION: The input light from the optical fiber 31 is focused with the condenser 30 at the toppest place of taper cam 34, passing through a beam splitter 28, being reflected with the reflection plate 27, further coming to the half mirror surface 28a of a splitter 28, being reflected to the right angled direction, and comes into the end surface 29a of optical fiber. At this time, the focus of input light is so arranged as to coincide with the end surface 29a. Further, the input light scatters and comes into the fiber 29 at the lowest place of taper cam 34. Therefore, the input light becomes largest at the toppest place of cam 34, decreasing at the lowest place of it, and the movement of moving axis 33 can be detected with the difference between both the quantities of light.
YOKOTA TAKASHI
TERAI SEIJI
