by sensing driving condition of record carrier, e.g. travel, tape tension

Full Title

Driving, starting or stopping record carriers of filamentary or web form; Driving both such record carriers and heads; Guiding such record carriers or containers therefor; Control thereof; Control of operating function (driving or guiding heads G11B3/00 - G11B7/00, G11B21/00) > Control of operating function, e.g. switching from recording to reproducing > by sensing features present on or derived from record carrier or container (G11B15/16 takes precedence) > by sensing driving condition of record carrier, e.g. travel, tape tension