In a tape threading mechanism having a threading arm for moving a leader block from a tape cartridge to a take-up reel, the take-up reel is provided with a guide groove having an intrusion port in the vicinity of the outer periphery of the take-up reel so as to guide a leader block toward the take-up center of the take-up reel. The filter component includes concentrically arranged filtering elements disposed in a filter-in-filter configuration. The silos selectively store data. Equivalent planes represented by {110} surfaces, are preferentially oriented parallel to a film surface in the Heusler alloy layer. A spotter optic is located in the second rear surface of the front element.