| 摘要 |
In recording and/or reproducing signals on a tape (13) running between supply (14) and take-up reels (15) on which the tape (13) is wound, the tape position is detected by initially determining the radii of the outer turns of the tape (13) on the supply (14) and take-up reels (15) with the tape in a reference position, generating signal pulses in response to rotation of the reels (14, 15) for movement of the tape (13) from the reference position, counting the numbers of such signal pulses generated during movement of the tape (13) from the reference position to an arbitrary tape position, and calculating at least one of the radii of the outer turns of the tape (13) on the supply (14) and take-up reels (15) for the arbitrary tape position on the basis of the corresponding radii for the reference tape position and the numbers of the signal pulses counted during movement of the tape (13) from the reference position to the arbitrary tape position. The length along the tape (13) from the reference tape position to the arbitrary tape position may also be calculated on the basis of the radii on the supply (14) and take-up reels (15), respectively, for the reference tape position, and the numbers of signal pulses counted in correspondence to the revolutions of the supply (14) and take-up reels (15), respectively, during movement of the tape (13) from the reference position to the arbitrary tape position. |
