| 摘要 |
PURPOSE:To elevate the detection accuracy while facilitating the assembly and adjustment by a method wherein two plate bodies formed by combining two deflecting plates with the transmission axes thereof shifted by 45 deg. from each other are arranged facing each other and a light source and a light receiving section are provided sandwiching these deflecting plates while a section for correcting the quantity of light is provided. CONSTITUTION:A large-diameter deflecting plate 11 and a small-diameter deflecting plate 12 are laminated one upon another with the transmission axes thereof shifted by 45 deg. to form a first plate body 10. On the other hand, deflecting plates 41 and 42 are fixed with the transmission axes thereof shifted by 45 deg. from each other and the separate body is arranged as opposed to the non-laminated part of the first plate body 10. Four pairs of light sources 21-24 and light receiving sections 31-34 are arranged facing one another sandwiching these plate bodies 10 and 40. Cyclic lighting signals 90 deg. in the phase are transmitted to respective pairs of light sources 21 and 22 and 23 and 24 and a relative rotational displacement is detected between the plate bodies 10 and 40 from outputs of the light receiving sections 31-34. Moreover, the light reception outputs as opposed to the light sources 23 and 24 are compared with the set value to correct the lighting signals. |
