| 摘要 |
PURPOSE:To enable the adjustment of balance easily in a short time, by indicating the angle from a reference position on the balance correction surface of a rotor to enable easy and accurate recognition of the position to which a balance weight is to be attached. CONSTITUTION:A plurality of projections are formed and arranged at each specified angle on the first balance correction surface 38a comprising the central surface portion of a motor rotor 38 at a polygonal mirror 31 while one thereof is set at the reference position. Then, a plurality of groove sections are formed and arranged at each specified angle on the second balance correction surface comprising the central surface portion of a planar member 100 fixed on the lower end face of an internal magnetic ring 40 mounted on a cylinder 37 while one thereof is set at the reference position coinciding with the reference projection. With such an arrangement, positions on the first balance correction surface 38a and the second balance correction surface to which balance weights 101 and 102 shall be attached can be recognized easily and accurately thereby enabling the balance adjustment in a short time. |
