| 摘要 |
PURPOSE:To hold the running capacity of a tape well for a long period by setting the surface electric resistivity of a cylindrical conductive material which consists essentially of a plastic resin and contains a carbon blask or the like, to a value in a prescribed range. CONSTITUTION:..A tape guide 1 should be set to the tape leading-out hole of a video tape cassette and is cylindrical and is constituted with a synthetic resin consisting essentially of, for example, a polyoxymethyl POM. Electric resistivities of plural tape guides 1 are measured preliminarily, and they are set to the video tape cassette to run the tape actually. If the surface electric resistivity is 0-10<2>OMEGA, the tape back tension is increased by electrification of the guide 1, and a safely device of a reproducing device is operated to stop running the tape. If the resistivity is 10<10>-10<14>OMEGA, the quantity of electrification is increased when the tape is run repeatedly at a low temperature of about 5 deg.C, and the back tension is increased then to stop running the tape. If the resistivity is 10<3>-10<9>OMEGA, the tape is run well.
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