Tape tension measuring device

摘要

A tape-tension measuring device is made to be interchangeable with a tape cassette in a cassette-type magnetic recording and/or reproducing apparatus for accurately indicating the tension produced in the recording and reproducing modes of such apparatus. The tape-tension measuring device has a casing equivalent to the housing of the tape cassette to be interchanged therewith, and first and second reel assemblies corresponding to the take-up and supply reels of a tape cassette are provided within the casing to receive the take-up and supply reel shafts of the recording and/or reproducing apparatus. The second reel assembly has inner and outer ring portions which are relatively rotatable against the resistance of a spring in response to the tension in a test tape which extends between and is wound on the reel assemblies. The test tape is guided between the reel assemblies so that the recording and/or reproducing head and the erasing head of the apparatus remain free of the test tape to avoid influencing the tape tension produced by the cooperative action of the capstan and pinch roller of the apparatus. A tape cleaning member ensures that a clean section of the test tape is engaged by the capstan and pinch roller.