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

摘要

Error components, such as eccentricity implicated in an encoder itself can be superimposed upon a detected value from a light receiving element due to assembly errors of assemblies themselves and in the manufacturing process. As a result, speed cannot be controlled with high accuracy and wow and flatter can not be reduced. A tape speed (TSS) signal detected and corrected from the tape transport by FG (18) and PG (19) 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 (41) in response to a reference clock generated therein and this data is temporarily stored in a first-in-first-out memory FIFO (44). When this data is reconverted by a D/A converter (43) 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, it becomes possible to erase the wow and flatter of the drive mechanism system from the head reproduced signal.