Importance

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Abstract

A capstan controlled tape transport mechanism that includes a tape tension controller for preventing tape slack in the tape path is presented. The transport mechanism includes a capstan, a spinnable reel, and a reel motor which controls the speed of revolution of the reel in response to a reel motor voltage/current. The spinning of the reel results in the winding of the tape around the reel to generate a tape stack whose radius varies according to the amount of tape wound around the reel hub. Each revolution of the reel generates a fixed number of reel tach pulses per reel revolution. The spinnable capstan controls the transport of tape across the capstan in the direction of the reel, generating a fixed number of capstan tach pulses per capstan revolution. The tape tension controller calculates a target count representing the expected number of capstan tach pulses per reel tach pulse based on the current tape stack radius, and monitors the received number of capstan tachs per received reel tach at the current tape stack radius. If the received number of capstan tachs exceeds the target count, the tape tension controller increases the reel motor voltage/current to cause the reel to spin faster to take up any existing slack in the tape path. Once the tape tension controller starts to receive reel tach within the target number of capstan tachs for the given tape stack radius, any existing adjustment voltage is ramped back down to the nominal reel motor voltage/current.

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First Claim