发明名称 Changeable character sign structure
摘要 Sign having self-storing characters which are quickly changeable. The face of the sign has a patterned array of openings juxtaposed against a contrasting background. The background may be supplied by color contrast and/or by illumination.
申请公布号 US4164824(A) 申请公布日期 1979.08.21
申请号 US19780924624 申请日期 1978.07.14
申请人 MINNESOTA MINING AND MANUFACTURING COMPANY 发明人 NIDELKOFF, JAMES G.
分类号 G09F9/37;(IPC1-7):G09F9/32 主分类号 G09F9/37
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