发明名称 System for positioning photographic transparencies correctly for projecting uses marks or cut-away corners on transparency frames
摘要 The system consists of marks (2) such as numerals in the corners of the transparency frame (1) which enable the user to insert the transparencies in a holder the right way up for projecting onto a screen. The corners of the frame can also be scored to allow one or more to be detached to indicate the correct position of the transparency.
申请公布号 FR2815431(A1) 申请公布日期 2002.04.19
申请号 FR20000013346 申请日期 2000.10.16
申请人 CROCY JEAN LOUIS 发明人 CROCY JEAN LOUIS
分类号 G03B21/64;(IPC1-7):G03B21/64 主分类号 G03B21/64
代理机构 代理人
主权项
地址