We have presented a high density MUSE videodisc with 60 minutes of playback time per side. We have continued examining the optical pick-up and the disc parameters, and we determined the newly specifications. The optical pick-up using a small packaged visible laser diode and an objective lens with an N.A. of 0.55 was employed. And the main carrier frequency was set to 12.5 MHz. Under these conditions, we obtained the fine played back image, and the SN ratio was 44dB or more.
This paper describes a study for tape driving force of magnetic recor d-ing or reproducing apparatus. First, we have cleared the parameter that influences tape driving force. Next, we have formulated each parameter which has a great influence on tape driving force. And we inspected that this formula is in fair agreement with the experiment.
In order to make the recording time longer in VCRs, one of methods is to make the tape thinner. But stiffness of the thin tape generally becomes less, and that increases the space between the tape and the magnetic head. This time we investigated the influence of tape stiffness of transverse direction and improve tape to head contact by optimizing a head's radius of curvature of track widh direction and tape tension.
The eficcient method for numerical simulation of tape floating behavior in VTR has been developed. Discrete Reynolds equation and discrete elastic equation were solved using Newton-Raphson method. We also investigated tape floating behavior for several drum-guide-tape system, which have some means to decrease tape / drum spacing in the head entrance region.