| 摘要 |
PURPOSE:To restrain the flexural quantity of a sleeve to <=0.2mm. even if a permanent magnet having >=500mm. length is used, by arranging a supporting member which is brought into contact with the surface of the cylindrical sleeve consisting of a nonmagnetic member where a permanent magnet member having plural magnetic poles on the surface is stored. CONSTITUTION:A permanent magnet roll 1 is constituted by arranging a permanent magnet member 3 in a cylindrical sleeve 2 consisting of the nonmagnetic member. The permanent magnet member 3 is formed by fixing a cylindrical permanent magnet 4, which has plural magnetic poles on the surface, to a shaft 5. Contracted parts 5a and 5b of the shaft 5 are supported through bearings 6 and 6' by flange parts 7 and 7'. A supporting member 12 which is brought into contact with the surface of the permanent magnet roll 1 supported by side plates 11 and 11' of the developing device, and thus, the flexural quantity of the sleeve 2 is restrained to <=0.2mm. even if the permanent magnet member 3 longer than 500mm. is used. |
