| 摘要 |
PURPOSE:To simplify the supporting structure to support a revolving shaft and to realize the plastic polygon mirror and the forming mold thereof which can be reduced in cost by mounting a spherical member to the end of the revolving shaft which is integrally molded with a mirror body. CONSTITUTION:The plastic polygon mirror 10 is constituted of the revolving shaft 11 consisting of a resin and the mirror body 12 consisting of the resin. The mirror body 12 having the mirror surface 12b is integrally molded at one end 11a of the revolving shaft 11 and the spherical member 13 is mounted, i.e. inserted to the other end 11b. The center of the spherical member 13 has the center aligning to the axial line of the revolving shaft 11 and a part of the spherical member 13 is exposed from the front end of the revolving shaft 11. The forming mold has a 1st cavity 15 to mold the revolving shaft 11, a 2nd cavity 16 to mold the mirror body having the plural mirror surfaces on the circumferential surface and a sprue 17. Since the spherical member 13 is inserted to the revolving shaft 11 by utilizing the gate sealing structure of injection molding, the molding of the plastic polygon mirror is facilitated. |
