| 摘要 |
PURPOSE:To easily obtain the tape traveling time by installing the first and second detection circuits detecting the numbers of rotation of the first and second reels, the memory storing the inclination constant of the graph of broken line which approximates the relation between the sum of the numbers of rotation of both reels and the tape traveling time, and an arithmetic circuit. CONSTITUTION:The speed detectors 4 and 5 detect the numbers of rotation of the reels 1 and 2. When either of counters 14 and 15 become a fixed value (100 pulse in the example), both counters are reset and restart to count. K-storing memory 18 stores beforehand an (n) number of constants (Kn) which are needed when the elapsed time (t) is computed in correspondence to the numbers of rotation NL and NR from pulse counters 14 and 15. Arithmetic circuit 19 determines the elapsed time based upon the operation of Kn (NL+NR) with the numbers of rotation NL and NR and the constant (Kn) of the memory 18. The calculation Kn is as follows: Namely, the approximate graph of broken line is made based upon the related curve of NL+NR with the elapsed time (t). The constant Kn showing the inclination of the broken line consists of twenty K1- K10 straight lines, but the constant Kn is symmetrical with t10 as a center. Consequently, ten divisions are made upto time t10, and respective divisions are approximated by straight lines of constants K1-K10 and stored in the memory 18. |
