发明名称 Camera having a magnetic head and capable of detecting exposed frames by counting data items in a magnetic recording track
摘要 A camera with a processing device for reading information recorded on an information recording medium corresponding to each frame of film, and for writing information into the information recording medium, includes a control circuit for substantially erasing a subset of a plurality of data items pre-recorded on the recording medium for each frame, by writing information on the recording medium for each frame with the processing device, and a judgment circuit for (i) counting a number of non-erased data items on the recording medium for each frame, (ii) comparing the counted number with a threshold value, the threshold value being less than a number of the plurality of pre-recorded data items, and (iii) judging that the writing of information has not been performed by the processing means when the counted number is greater than or equal to the threshold value.
申请公布号 US5281987(A) 申请公布日期 1994.01.25
申请号 US19910786884 申请日期 1991.11.01
申请人 CANON KABUSHIKI KAISHA 发明人 NAGATA, TORU
分类号 G03B17/24;(IPC1-7):G03B17/24 主分类号 G03B17/24
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