Lateral tape motion detector

摘要

A tape edge sensor system for detecting lateral movement of a storage tape includes a first photo-emitter, a first photo-detector positioned to receive a first light signal from the first photo-emitter, a first aperture disposed between the first photo-emitter and the first photo-detector, and a feedback system connected to the first photo-emitter and the first photo-detector. The first aperture defines a first region at a first tape edge through which the first light signal is received by the first photo-detector with the storage tape blocking a portion of the first light signal. The feedback system determines the first photo-detector's signal amplitude and adjusts the first light signal such that the first photo-detector signal amplitude is within a first average amplitude range. A tape edge sensor system using compensating photo-interrupters is also provided.