| 摘要 |
1,258,804. Feeding record tapes. BURROUGHS CORP. 7 Feb., 1969 [12 Feb., 1968], No. 6622/69. Heading G5R. Two photo-electric sensing means 12b, 14b are spaced transversely of a movable record tape 18 so that each is illuminated only in the presence of a reflective marking 20, 22 in the corresponding half of the tape, the two sensing means being connected in a circuit which provides a first output signal (e.g. zero) when both sensing means are either illuminated or not illuminated and a different output signal when either sensing means is illuminated alone. A reflector 24 on the far side of the tape enables a third photo-electric sensor 26 to detect a transparent section or the end of the tape. |
