Phonograph
    6.
    发明授权
    Phonograph 失效
    留声机

    公开(公告)号:US2300150A

    公开(公告)日:1942-10-27

    申请号:US38926741

    申请日:1941-04-19

    Applicant: RCA CORP

    Inventor: GUEDON EMILE C

    CPC classification number: G11B19/14

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