Stepping motor

Abstract

A stepping motor for optical pick-up devices is disclosed. In the stepping motor, a stator, having a coil and a yoke, is fixed to a first support plate. A rotating shaft is rotated by the coil of the stator, with a first end of the shaft being inserted into the stator and a second end being exposed outside the stator and being externally threaded to form a lead screw. The first and second ends are each domed. A first holder, having a trapezoidal dent, rotatably holds the domed first end of the shaft within the trapezoidal dent while being brought into point contact with the domed first end. A second holder, having a trapezoidal dent, rotatably holds the domed second end of the shaft within the trapezoidal dent while being brought into point contact with the domed second end. The second holder is supported by a second support plate while being normally and elastically biased by a spring means in an axial direction of the rotating shaft, thus elastically supporting the shaft in the axial direction. Due to such a simple support structure for the rotating shaft, the stepping motor has a reduced number of elements and is easily produced through a simple process while accomplishing improved operational reliability and improved productivity and reducing the operational noises.

Dependencies are inferred from the claim text.