| 摘要 |
<p>PURPOSE:To increase the display precision of remaining time by making the increase of physical ROM capacity a reference table and interpolating with a prescribed expression. CONSTITUTION:When the rotational cycle of a reel is T, the line velocity of a tape is V, the area of a reel hub is S, the thickness of a tape to use is B and 1/2pi=A are defined, tape remaining time Rem is usually calculated with the expression I by detecting a reel pulse. In such a manner, since a cutting-off error is generated by the physical limitation of a ROM table, the remaining time with high precision is incapable of finding. Then, a differential coefficient Rem', the expression II obtained by differentiating the expression I is multiplied to the omitting difference DELTATsec omitted, the multiplied expression is added to the expression I as an interpolating data, and the expression III interpolating the gap of quantization is defined, the calculating precision of the remaining time is improved remarkably while holding the ROM table to a small size. The remaining time is calculated by the expression III since the cycle Tsec of two revolutions of the feeding reel 1a is detected by a reel pulse detector 3. The reel pulse is inputted to a micro-processor 5 through a waveform forming shaping circuit 4 and the cycle T is represented with hexadecimal number of maximum 12-bit length.</p> |
