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公开(公告)号:US2301980A
公开(公告)日:1942-11-17
申请号:US35333640
申请日:1940-08-20
Applicant: MAX STEENBECK
Inventor: MAX STEENBECK
IPC: H01J17/04
CPC classification number: H01J17/04
公开(公告)号:US2301980A
公开(公告)日:1942-11-17
申请号:US35333640
申请日:1940-08-20
Applicant: MAX STEENBECK
Inventor: MAX STEENBECK
IPC: H01J17/04
CPC classification number: H01J17/04