Tape speed sensor, control circuit using tape speed sensor and method of controlling tape speed sensor using control circuit

Abstract

An error component such as an eccentricity implicated in an encoder itself is superimposed upon a detected value from an FG due to an assembly error of assemblies themselves and in the manufacturing process. As a result, a speed could not be controlled with a high accuracy and wow and flatter could not be reduced. A tape speed (TSS) signal detected and corrected from the tape transport by FG and PG is inputted into a PLL loop within a data controller (TBC) of a reproducing system. A reproduced signal is converted by an A/D converter in response to a reference clock generated therein and this data is temporarily stored in an FIFO. When this data is reconverted by a D/A converter into an analog signal, if this data is sequentially converted at a timing of an absolute control clock of a quartz oscillator, then it is possible to eliminate the error component superimposed upon the head reproduced signal. Thus, from a theory standpoint, it becomes possible to erase the wow and flatter of the drive mechanism system from the head reproduced signal.