| 摘要 |
A group of film cassettes (1) individually comprise a rotary disk (7), a bar code on the disk having alternating spaces and bars which when optically detected can provide film-related information and a measure of the angular position of the disk, and eye detectable film exposure status indicia (15,17,19) and a corresponding indicator (11a) one of which is on the disk and the other is fixed to align respective ones of the exposure status indicia and the indicator in accordance with the angular position of the disk. The bar code (9) is visible substantially only to infrared radiation to make it essentially invisible to the human eye but to allow it to be optically detected with infrared radiation, and has at least one space (11a) and/or bar with the same location on the disk for each of the cassettes. The indicator or exposure status indicia on the disk is superimposed or integrated with the one space and/or bar to economize available space on the disk, and is optically indistinguishable in infrared radiation from the one space and/or bar to prevent its being optically detected with infrared radiation. <IMAGE> |
