| 摘要 |
PURPOSE:To attain rapid rotation and to improve abrasion resistance by forming at least one of upper and lower faces of a rotary polygonal mirror as a face supporting thrust load and forming at least a part of the supporting face with a ceramic. CONSTITUTION:The rotary polygonal mirror 10 is supported by at least one of its upper and lower faces without being supported only by a rotary shaft 12. In this case, at least a part of the face supporting the thrust load is formed with a ceramic 20. It is preferable to set up the porosity of the porous ceramic body to 10-60% by volume. On the other hand, the diameter of an opened pore is preferably set up to <=10mum. Consequently, an excellent property in the abrasion resistance of the ceramic 20 and high strength can be sufficiently displayed. |
