发明名称 Camera having a magnetic flux shielding device
摘要 A camera having a shielding device to prevent leaked magnetic flux generated by a drive motor from affecting magnetic information recorded on film in a camera in which a drive motor is provided within a winding spool. The shielding device includes an inner shielding member and an outer shielding member which shield magnetic flux from the drive motor, even if the intensity of the magnetic flux leaked from the motor fluctuates. The outer shielding member is made of permalloy B with a high maximum relative permeability, and is provided outside of a motor housing case for the drive motor. The motor housing case forms the inner shielding member, and is made of pure iron having a high saturated magnetic flux density. The leaked magnetic fluxes generated by the drive motor having a strong magnetic field intensity are shielded by the motor housing case while other leaked magnetic flux having a weak magnetic field intensity is shielded by the outer shielding member.
申请公布号 US5857123(A) 申请公布日期 1999.01.05
申请号 US19970921513 申请日期 1997.09.02
申请人 NIKON CORPORATION 发明人 MIYAMOTO, HIDENORI;OTANI, TADASHI
分类号 G03B17/00;C22C19/03;G03B17/02;G03B17/24;G03B17/42;H02K5/00;(IPC1-7):G03B17/24 主分类号 G03B17/00
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